DE212022000196U1 - Exchanger tube for a heat exchanger and heat exchanger - Google Patents

Abstract

Exchanger tube (10) for a heat exchanger (1) which extends in a transverse direction (Y) with a cross section perpendicular thereto which is elongated in a longitudinal direction (X) with respect to a vertical direction (Z), the exchanger tube (10) The following includes:
- an outer jacket (20) which is formed from a single first metal strip (21) and surrounds an inner cavity (40), the outer jacket (20) comprising: a first side wall section (23) on a vertically first side (U) and a second side wall portion (25) on a vertically second side (L) extending in the longitudinal direction (X) and spaced apart in the vertical direction (Z), a rear portion (24) comprising the side wall portions (23, 25). on a longitudinally rear side (R), an inner front section (22) extending from the first side wall section (23) on a longitudinally front side (F) towards the second side (L), and an outer front section ( 26), which extends from the second side wall section (25) on the front side (F) towards the first side (U) and at least partially overlaps with the inner front section (22), the inner front section (22) being a inner convex portion (22.2) and the outer front portion (26) includes an outer convex portion (26.1) disposed outwardly from the inner convex portion (22.2) with respect to the inner cavity (40); and
- an inner rib (30), which is formed from a single second metal strip (31), is arranged at least largely within the outer jacket (20) and extends from a rear rib section (34) to a front rib section (32), which is at least partially between the inner front section (22) and the outer front section (26), the outer front section (26) having a spring section (22.4), which includes the inner convex section (22.2), from the first side ( U) engages and engages the spring section (22.4) from the second side (L) via the front rib section (32) arranged therebetween, whereby the spring section (22.4) is clamped in the vertical direction (Z).

Description

field of technology

The invention relates to an exchanger tube and a heat exchanger.

State of the art

In vehicles such as cars or trucks, heat exchangers are used as part of cooling circuits, which in turn are required to cool vehicle components such as engines, transmissions, etc. Some of these cooling circuits use a liquid heat exchange medium that absorbs heat from the vehicle's components and transfers it to the ambient air at the main heat exchanger, such as a radiator installed in the front of the vehicle. In other cases, the heat exchanger is a condenser, in which the heat exchange medium (or fluid) enters the condenser in a gaseous state, is condensed and cooled in the condenser, and leaves the condenser in a liquid state.

According to a common construction, the heat exchanger includes an inlet manifold connected to a heat exchanger core. The heat exchanger core typically includes a plurality of spaced-apart exchanger tubes, which are largely responsible for the heat exchange between the fluid and the ambient air. The airflow required to cool the fluid can be provided to the exchanger core by forced or natural convection. One could say that the fluid is received in the inlet tank, from where it is distributed to the exchanger tubes. The fluid is directed from the exchanger tubes to an outlet container. According to another construction, an inlet cavity and an outlet cavity are provided as separate sections in a single container.

External ribs are often provided on the exchanger tubes in order to increase the effective surface and thus the heat transfer to the ambient air. As is well known, the individual tube is also provided with an internal structure, sometimes referred to as a turbulator or internal fin. These structures can serve multiple purposes. For example, they increase the surface area available for heat transfer, can facilitate the formation of nonlaminar, turbulent flow, and can increase the structural integrity of the tube. The inner fin typically extends along the length of the exchanger tube and defines a plurality of channels for the flow of a heat transfer fluid.

Heat exchanger tubes with a large number of channels are also known as multi-channel tubes. A known method for producing multi-channel pipes is the extrusion of a strand of a deformable heat-conducting material through a die. The extrusion process allows the inner fins to be formed to have intricate geometric features to improve heat transfer efficiency that other known manufacturing processes could not easily provide. However, the extrusion process is expensive because the extrusion die must be frequently replaced to maintain the desired dimensions of the complicated geometric features. Extruded pipes are also susceptible to corrosion attack from road salt and acid rain and require extensive anti-corrosion coatings for automotive applications, adding further complexity to manufacturing and cost.

Another known method for forming multi-channel pipes is to fold one or more sheets of a flexible, heat-conducting material (usually metal). Multiple channels can be defined by internal corrugated folds of sheet material that form the internal rib. Pleated tubes provide numerous advantages over extruded tubes in terms of lower cost and ease of manufacture for the tube itself as well as for the final assembly of the heat exchanger. One advantage is that folded tubes can be formed from thin strips of plated aluminum, providing excellent corrosion protection without the need to apply additional coatings. Sometimes a single sheet is used for the entire pipe, such as in the WO 2012/106242 A2 shown. According to another construction, a thinner sheet is used for the inner fin while a thicker sheet is used for the outer casing tube, as in US 2017/0144212 A1 , EP 3 399 267 A1 or US 2007/0095514 A1 shown. Yet another construction uses one thinner sheet for the inner rib and two thicker sheets for the outer shell, as in the DE 10 2008 052 785 A1 disclosed.

The front nose of the tube, that is, the portion oriented toward the front of the automobile, is exposed to incoming air to increase heat transfer efficiency as the vehicle moves in the forward direction. However, this configuration leaves the front nose vulnerable to impact damage from road hazards such as rocks and debris as well as for corrosion damage caused by environmental influences such as acid rain, road salt and wind friction. This is particularly true for folded tubes because the thickness of the front nose is the same as that of the thin strip of plated aluminum material from which the folded tube is made.

To overcome this problem, it has been proposed to provide multiple layers of sheet material in the front nose, either by folding a single sheet in multiple layers or by providing an overlap of multiple sheets. However, these measures complicate the formation and assembly process. Additionally, there is often a trade-off between maximizing stability and minimizing the weight of the pipe. Another problem arises when a special sheet metal is used for the inner rib because the position of the rib relative to the outer shell must be secured during the assembly process before they can be joined by a final brazing process.

Technical task

It is therefore an object of the present invention to provide a multi-channel exchanger tube for a heat exchanger which has advantageous mechanical stability in relation to its weight and is easy to manufacture.

This task is achieved by an exchanger tube according to claim 1 and a heat exchanger according to claim 17.

General description of the invention

The invention provides an exchanger tube for a heat exchanger. This can in particular be a heat exchanger for a vehicle such as a passenger car or truck. The heat exchanger is normally a condenser, to be installed in a front section of the vehicle or in any other part of the vehicle, as the case may be.

The exchanger tube, which can also be referred to as a “heat exchanger tube” or for the specific application as a “condenser tube”, extends in a transverse direction with a cross section perpendicular thereto, which is elongated in a longitudinal direction with respect to a vertical direction. In general, the terms “transverse,” “longitudinal,” and “vertical” are used in this framework to define a frame of reference with three pairwise orthogonal directions. In this respect, these terms should not be construed as limiting in any way. However, when the exchanger tube is installed in a heat exchanger in a vehicle, the longitudinal direction usually corresponds to the longitudinal axis (X-axis) of the vehicle, the transverse direction corresponds to the transverse axis (Y-axis) of the vehicle, and the vertical direction corresponds to the vertical axis (Z-axis) of the vehicle . The transverse direction usually corresponds to the largest dimension of the exchanger tube. The exchanger tube is usually straight and has a constant cross-section along the transverse direction. The cross section perpendicular to the transverse direction is elongated in the longitudinal direction with respect to the vertical direction; d. that is, the dimension of the exchanger tube in the longitudinal direction is larger than its dimension in the vertical direction, usually at least three times, at least five times or at least eight times larger. Due to the elongated cross section, the exchanger tube can also be referred to as a flat exchanger tube. The exchanger tube is flattened in particular in the vertical direction.

The exchanger tube includes an outer jacket that is formed from a single first metal strip and surrounds an inner cavity. The first metal strip can also be referred to as the first sheet and is usually made of aluminum or an aluminum alloy. It should be noted, however, that one or both surfaces of the first metal strip may be at least partially covered with a brazing material - for example an aluminum alloy such as AA4343 or generally the alloy series AA4XXX. The outer jacket surrounds an inner cavity, it being understood that the cavity is not completely enclosed by the outer jacket because the exchanger tube must have at least one opening at each of the two ends in the transverse direction so that the fluid can enter and exit the tube . It should also be noted that the internal cavity does not have to be continuous, but can be divided into several sections or sub-cavities that are not directly connected to each other, i.e. H. are not designed for direct fluid exchange. Of course, each of the sections could also be viewed as a cavity. It is understood that the outer shell normally provides a fluid-tight seal around the inner cavity perpendicular to the transverse direction (i.e., on either side in the longitudinal and vertical directions).

The outer shell includes a first sidewall portion on a vertically first side and a second sidewall portion on a vertically second side that extend in the longitudinal direction and are spaced apart in the vertical direction. The terms “first side” and “second side” only serve to distinguish two opposite sides of the exchanger tube along the vertical direction and are therefore not to be construed as limiting in any way. If it's in the Vehicle is installed, the side referred to herein as the “first side” may, for example, face up or down with respect to the direction of gravity. In some embodiments, the “first side” could also be referred to as the “top,” in which case terms such as “toward the first side” could be replaced with “up” or “over.” According to a common construction, both side wall sections are straight and parallel to the longitudinal direction. They are spaced apart in the vertical direction, with the above-mentioned internal cavity (or at least a part thereof) interposed therebetween. The outer shell further includes a rear portion connecting the sidewall portions on a longitudinally rear side. The terms “rear side” and “front side” only serve to distinguish two opposite sides of the exchanger tube along the longitudinal direction and should therefore not be construed as limiting in any way. However, when installed in a vehicle, the front side usually faces the front of the vehicle while the rear side faces its rear. It is to be understood that all sections mentioned herein are part of a single, continuous piece of metal - namely the first metal strip - and therefore the boundary between two adjacent sections may not be clearly visible. The rear section is often arcuate or curved in such a way that there is a smooth transition between the two side wall sections. However, other constructions are also possible. Since the rear section connects the sidewall sections, it extends along the vertical direction (but is usually not parallel to it).

An inner front portion of the outer shell extends from the first sidewall portion on a longitudinally front side toward the second side and an outer front portion of the outer shell extends from the second sidewall portion on the front side toward the first side and is at least partially overlapped with the inner front portion , wherein the inner front portion includes an inner convex portion and the outer front portion includes an outer convex portion disposed outwardly from the inner convex portion with respect to the inner cavity. The inner front portion extends from the first sidewall portion toward the second side, but generally not parallel to the vertical direction. It is called the “inner” front section because it is at least partially located closer to the inner cavity. It extends from the first side wall section on a (longitudinal) front side, which is of course opposite the rear side mentioned above. Likewise, the outer front portion extends from the front side of the second sidewall portion toward the first side, but generally not parallel to the vertical direction. Accordingly, each of the front portions extends from one sidewall portion to the other sidewall portion. Both front sections overlap at least partially in such a way that they form a double wall that separates the inner cavity from the outside of the exchanger tube. The inner front section includes an inner convex section, whereas the outer front section includes an outer convex section. In this context, the term “convex” refers to the shape as seen from the outside of the exchanger tube. Each convex section may be arcuate and curved continuously (or in sections), but it could also have at least one acute bend or kink. Normally the two convex sections partially or even completely overlap. In a configuration where the front side corresponds to the direction of travel of the vehicle, the front sections can be considered as elements of a front nose.

The exchanger tube further comprises an inner fin formed from a single second metal band, disposed at least mostly within the outer shell and extending from a rear fin portion to a front fin portion at least partially housed between the inner front portion and the outer front portion. The second metal band may also be referred to as a second sheet and is also typically made of aluminum or an aluminum alloy. As with the first metal band, one or both surfaces of the second metal band may be at least partially covered with a brazing material. The thickness of the second metal band is typically considerably less than the thickness of the first metal band because the inner fin is disposed mostly or entirely within the outer shell and thus does not need to have the same mechanical stability. Without limiting the invention in this respect, the inner fin may have various functions, such as increasing the surface area available for heat transfer, facilitating the formation of turbulent flow, and increasing the structural integrity of the tube. The rear rib portion is of course arranged on the longitudinal rear side of the inner rib, while the front rib portion is arranged on the front side. The front rib portion is at least partially received between the inner front portion and the outer front portion of the outer shell. One could also say that the front rib portion is at least partially received between the front portions of the outer shell clamped. On the one hand, this serves to secure the position of the inner fin in relation to the outer shell. On the other hand, an effective three-layer structure is formed that improves the mechanical stability on the front side of the exchanger tube, which usually corresponds to the front nose. Nevertheless, a relatively small amount of material is used, which is why the weight of the exchanger tube can be kept low.

The outer front portion engages a spring portion including the inner convex portion from the first side and engages the spring portion from the second side via the front rib portion disposed therebetween, thereby clamping the spring portion in the vertical direction. The term “clamped” thus refers to the fact that the spring section is held at opposite sections by the outer front section and thus acts as a support and/or guide frame. In some embodiments, the spring portion may be formed entirely by the inner convex portion, while in other embodiments it may include additional portions. Although the manufacturing method of the heat exchanger tube preferably includes elastic deformation of the spring portion, as discussed below, the term "spring portion" is not to be construed as limited to such an embodiment. The outer front portion engages the spring portion from the first side, i.e. H. it is in direct contact with the spring section from the vertical first side. On the other hand, the outer front section accommodates the spring section from the second side - i.e. H. from the vertical second side - engages indirectly via the front rib section. In other words, the outer front section directly engages the front rib section and the front rib section in turn directly engages the spring section. As a result, the outer front portion forms a bracket around the spring portion in the vertical direction, i.e. that is, the spring section is clamped vertically. As a result, the outer front portion forms a bracket around the spring portion in the vertical direction, i.e. that is, the spring section is clamped vertically. Accordingly, accurate positioning of the outer front portion, the spring portion and the front rib portion as well as a firm connection between these portions are formed. This is particularly helpful in a joining process such as a brazing process.

According to one embodiment, the spring portion is elastically compressed in the vertical direction (i.e., in the pipe thickness direction). In other words, the outer front section exerts vertical forces on the spring section, which cause elastic deformation of the spring section. It should be noted, however, that depending on the material of the outer jacket and the conditions of a brazing process, which normally involves heating of the entire exchanger tube, an elastic deformation of the spring section can turn into a plastic deformation. However, it is understood that elastic compression of the spring portion ensures close contact with the outer front portion or the front rib portion.

The inner front section advantageously includes an inclined section adjacent to the inner convex section, the inclined section being inclined/curved from the first side wall section towards the second side, whereby the inner convex section is offset from the first side wall section towards the second side and a End portion of the outer front portion on the first side is arranged relative to the inner convex portion. In this embodiment, the inner convex portion is not disposed directly adjacent to the first sidewall portion, but the oblique portion is disposed therebetween. The slanted portion is disposed at an angle with respect to the first sidewall portion; it is particularly towards the second side, i.e. H. towards the second side wall section, diagonally. The slanted portion typically includes a convex subsection adjacent the first sidewall portion and a concave subsection adjacent the inner convex portion. In other words, the angle between the inclined section and the first sidewall section initially increases and then decreases again. At the transition between the oblique section and the inner convex section, the inner front section can even be parallel to the first side wall section. The inner convex portion is offset from the first side wall portion toward the second side by interposing the oblique portion. This results in an additional space being available on the first side relative to the inner convex section, which in this embodiment is occupied by an end section of the outer front section.

The inclined section preferably has an inclination of less than 70° with respect to the first side wall section. Since the transition between the sloping section and the adjacent sections is usually not abrupt, the slope is usually not consistent. As such, the statement refers to the maximum inclination (or angle of inclination) in relation to the first side wall section. This is usually identical to the inclination with respect to the longitudinal direction. If the inclination is limited to less than 70°, this helps to avoid an excessively acute bend between the first sidewall portion and the slanted portion, which in turn reduces the stress on the first metal strip during the forming process. In some embodiments, the tilt can even be limited to less than 60°.

The cross section of the end section can be adjusted to better match the cross section of the inner front section. According to such an embodiment, the end portion comprises a tapered cross section and is disposed adjacent the oblique portion. The cross section of the end section tapers, i.e. H. the thickness of the end section decreases towards its edge. This allows the end section to be positioned adjacent to and at least close to the slanted section. In particular, the end section can be in contact with the inclined section at several points and/or over a certain distance. This in turn makes it possible to join the end section to the inclined section, for example by brazing.

There are various ways in which the tapered cross section can be achieved. The thickness could decrease gradually and/or stepwise. The decrease could remain the same along the length of the end section or it could vary. According to one embodiment, the tapered cross section is a wedge-like cross section with a wedge angle of less than 70°. The wedge angle usually remains the same but may vary along the length of the end section. The size of the wedge angle can be selected according to an inclination of the inclined portion with respect to the first side wall portion.

It is highly preferred that the outer front portion be flush with the first sidewall portion with respect to the vertical direction. In other words, the outer front portion extends along the vertical direction to the same position (i.e., the same "height") as the first sidewall portion. This can result in a straight top of the exchanger tube, the top being formed primarily by the first sidewall portion and to some extent by the outer front portion. It should be noted that this embodiment is preferably combined with (and facilitated by) the above-mentioned embodiment in which the end portion has a tapered cross section.

For secure connection and also to improve the stability of the front of the exchanger tube, it is preferred that the front rib section is joined to the inner front section and the outer front section. This joining usually corresponds to a brazed connection. As explained above, the outer shell and/or the inner fin may be covered with a braze material such that after formation and assembly of the outer shell and inner fin, the entire exchanger tube can be heated to melt the braze material and thereby all braze joints in the exchanger tube to be attached at the same time.

It is also preferred that the end portion be joined to the oblique portion. This joining is also normally achieved by brazing. This joining connection can be facilitated and improved by a tapered cross-section of the end portion which is adapted fairly closely to the cross-section of the oblique portion.

One embodiment provides that the front rib portion extends in the vertical direction over 30-60% of a height of the inner cavity defined by a distance of the side wall portions in the vertical direction, and that the inner front portion and the outer front portion are separated by one Space on the first side are separated relative to the front rib section. The height of the inner cavity is the vertical distance between the first sidewall portion and the second sidewall portion. If this distance does not remain the same, the "height" in this frame is specifically the vertical distance at the front side of the side wall sections that adjoin the inner and outer front sections. Since the front rib portion is received between the inner and outer front portions, it extends toward the first side. As mentioned above, the end portion of the outer front portion is preferably joined directly to the slanted portion, and therefore the front rib portion should not extend to the end portion. It has even been found that the front rib section should preferably terminate at a certain distance from the end section. Because of the finite thickness of the front rib section, there is a gap between the inner and outer front sections on the first side relative to the front rib section. This gap may gradually decrease toward the end portion, which may be in contact with the slanted portion and possibly with the inner convex portion. To facilitate this, the front rib section should extend to a maximum of 60% or only 50% of the height of the internal cavity cken. On the other hand, the front rib section should extend to at least 30% or 40% of the height, which, for example, helps maintain tension on the spring area. It should be noted that in the gap region, the outer front portion can be deformed into the gap to some extent without corresponding deformation of the inner front portion. In other words, there is a region where the deformation of the front sections is decoupled (to a certain extent), which can be beneficial for the shock resistance of the exchanger tube.

In one embodiment, the inner front portion includes a leg portion adjacent the inner convex portion, the front rib portion being at least partially received between the leg portion and the second sidewall portion. The leg section can be part of the spring section. The leg section can serve, in particular during the formation and assembly of the exchanger tube, to introduce an elastic deformation force into the inner convex section. The leg section is arranged opposite the second side wall section and, in the assembled state, is normally parallel to the second side wall section and the first side wall section. However, it is possible for the leg portion to initially be at an angle with respect to the first sidewall portion such that when the upper and second sidewall portions are moved to their final parallel position, it must be deflected to achieve the parallel position , which in turn creates an elastic deformation force on the inner convex section.

Preferably, the rear rib portion engages the rear portion in the longitudinal direction. In other words, the inner rib extends the entire length of the inner cavity such that the rear rib portion is in contact with the rear portion of the outer shell. The inner rib can be deformed elastically, in particular in the longitudinal direction, such that the rear rib section presses against the rear section of the outer casing.

The inner fin normally comprises a central fin section between the rear fin section and the front fin section, the central fin section being at least partially corrugated and in contact with both side wall sections. The cross section of the central fin section is at least partially corrugated, corresponding to a meander, zigzag or wave shape. The central fin section is accordingly directed alternately towards the first and second side between the upper and second side wall sections and is in contact with the first side wall section and the second side wall section, respectively, at certain points. It is also possible that the vertical dimension of the central fin section is chosen to be larger than the height of the inner cavity prior to assembly, such that it has to be deformed (elastically and/or plastically) during assembly of the exchanger tube. It is understood that the central fin section divides the inner cavity into subsections, i.e. sub-cavities. This effectively creates a plurality of flow channels within the heat exchanger tube, which facilitates the generation of turbulent flow. Accordingly, the exchanger tube can be regarded as a multi-channel tube. The corrugated structure also increases the contact area between the fluid and the heat exchanger tube, thereby improving heat transfer. Finally, the corrugated structure improves the mechanical stability of the heat exchanger tube.

It is preferred that the central rib portion be joined to both sidewall portions. Again, this joining is usually accomplished by brazing. By joining the middle section to the first and second side wall sections, the position of the inner rib is secured relative to the outer jacket and the mechanical stability of the exchanger tube is improved.

The inner rib preferably includes a stop portion disposed proximate the inner front portion and extending in the vertical direction over at least 50% of the height of the inner cavity, the stop portion being at least partially at an angle of greater than 60° with respect to the longitudinal direction runs. Such a stop section can easily be integrated into a corrugated structure. As will be explained below, when assembling the exchanger tube, the stop portion may be in contact with the inner front portion, while the rear rib portion is in contact with the rear portion of the outer shell such that the inner rib is held in a position near the first side wall portion before the outer casing is closed. If the angle between the stop section and the longitudinal direction is less than 60°, there is an increased risk that the stop section will slide off the inner front section during assembly. The same applies if the stop section extends over less than 50% of the height. Furthermore, the nominal distance between the stop section and the opposite end of the inner rib is advantageously greater than the distance between the inner front section and the bottom of the rear section so that the inner rib is slightly compressed during assembly when the stop section is engaged on the inner front section. The spring force of the inner rib in the direction of the tube width also helps to keep the inner rib in place during assembly.

The invention further provides a heat exchanger, in particular a heat exchanger for a vehicle. The heat exchanger comprises a first container and a second container for a fluid, each extending in the vertical direction, the first container defining an inlet container cavity and one of the containers defining an outlet container cavity. The first and second containers, which can be referred to as manifolds or integral manifolds at least in some embodiments, are designed to receive a fluid during operation. The term "fluid" refers herein to a liquid or gaseous medium. The respective fluid is of course the medium of a cooling circuit to which the heat exchanger belongs when it is installed in the vehicle, for example. The fluid can also be referred to as cooling fluid, cooling medium, coolant or refrigerant. Each container extends along the vertical direction and is normally elongated with respect to the vertical direction. The term "vertical direction" is to be understood in the sense explained on the first page with respect to the exchanger tube according to the invention; This means that when the exchanger tube is installed in the vehicle, the vertical direction corresponds to the Z-axis (vertical axis) of the vehicle, but it could also correspond to a horizontal axis such as the Y-axis of the vehicle.

The first container defines an inlet container cavity and one of the containers (the first container or the second container) defines an outlet container cavity of the heat exchanger. The inlet tank cavity, which may also be referred to as an inlet tank space or inlet tank volume, is a cavity of the heat exchanger that receives a fluid, for example, from vehicle components such as a water jacket of an engine, a transmission cooler, a battery pack or the like, the fluid being subsequently cooled in the heat exchanger, before it is returned to the vehicle's cooling circuit. In this regard, the first container has at least one inlet channel which communicates with the inlet container cavity. During operation, the fluid from the outlet container cavity is distributed back to the vehicle components via at least one outlet channel of the respective container. The outlet container cavity can also be referred to as an outlet container space or outlet container volume. Although the invention is not limited to this, the heat exchanger may in particular be a condenser adapted to receive a fluid in a gaseous state and to discharge the fluid in a liquid state. In this case, the fluid is in a gaseous state in the inlet container space and in a liquid state in the outlet container space.

The heat exchanger further includes an exchanger core designed for heat exchange of the fluid with the ambient air and comprising a plurality of exchanger tubes according to the invention, the exchanger tubes being adapted to direct the fluid from the inlet container cavity to the outlet container cavity. The exchanger core can extend along the transverse direction and along the vertical direction, with the exchanger tubes extending along the transverse direction. During operation, the ambient air flows along the exchanger core, promoting heat exchange between the ambient air and the fluid. In other words: the heat exchange process takes place almost entirely at the exchanger core. The fluid flows through the exchanger tubes, which are designed to direct the fluid from the inlet container cavity to the outlet container cavity. Each exchanger tube is connected such that it receives the fluid directly or indirectly from the inlet container cavity and directs it directly or indirectly to the outlet container cavity. It is understood that the exchanger core usually includes structures such as external fins to increase its surface area and thus improve heat exchange with the surrounding air. The outer ribs can be arranged between the tubes and partially or completely cover the tube width.

The disclosure further provides a method for producing an exchanger tube for a heat exchanger, wherein the exchanger tube extends in a transverse direction with a cross section perpendicular thereto which is elongated in a longitudinal direction with respect to a vertical direction. If these and other terms have been explained above in relation to the exchanger tube according to the invention, they will not be explained again herein.

The method includes forming an outer shell from a single first metal strip such that the outer shell includes: a second sidewall portion on a vertically second side, a first sidewall portion on a vertically first side, a rear portion including the sidewall portions on a longitudinally rear side connects, an inner front portion extending from the first sidewall portion on a longitudinally front side toward the second side, and one an outer front portion extending from the second sidewall portion on the front side toward the first side, the inner front portion including an inner convex portion and the outer front portion including an outer convex portion.

The method further comprises forming an inner rib from a single second metal strip, the inner rib extending from a rear rib portion to a front rib portion. This may be performed before, after and/or during the formation of the outer shell described above.

In a further step, the inner rib is arranged between the side wall sections, i.e. H. between the second side wall section and the first side wall section. It is understood that in this condition the side wall sections are not in their end positions, but rather that one side wall section could be at an angle with respect to the other side wall section, similar to an open lid. The inner front section and the outer front section are also spaced apart with an opening therebetween through which the inner rib can be inserted.

After the inner rib is disposed between the sidewall portions, the outer shell is closed to surround an inner cavity and the inner rib is at least largely disposed within the outer shell, the outer front portion at least partially overlaps the inner front portion, the front rib portion is at least partially received between the inner front portion and the outer front portion, the outer convex portion is disposed outwardly from the inner convex portion with respect to the inner cavity, the sidewall portions extend in the longitudinal direction (X) and are spaced apart in a vertical direction, and the outer front portion engages a spring portion comprising the inner convex portion from the first side and engages the spring portion from the second side via the front rib portion disposed therebetween, whereby the spring portion is clamped in the vertical direction.

Forming the outer casing can be accomplished by gradually deforming the first metal strip as it is passed in the transverse direction through a sequence of roll forming stations. Each roll forming station may include one roll or a plurality of rolls that perform bending operations on the profile of the first metal strip. The outer casing can also be closed in this way. A similar procedure can be used to form the inner rib.

The method can further include carrying out at least one joining process, in particular a brazing process, after the outer jacket has been closed. This is typically done by exposing the entire exchanger tube to an elevated temperature to melt a brazing material.

Preferred embodiments of the method generally correspond to those of the exchanger tube according to the invention and will therefore not be explained again.

Closing the outer shell preferably includes plastically deforming the outer front portion to engage the spring portion, thereby elastically compressing the spring portion in the vertical direction. This elastic deformation or compression of the spring section has already been mentioned above. It contributes significantly to forming a close contact between the spring section and the outer front section. As also mentioned above, the elastic deformation could turn into plastic deformation if the heat exchanger tube is exposed to an elevated temperature during brazing.

It is also preferable that an end portion of the outer front portion is formed with a tapered cross section by performing at least one rolling process on the end portion. During the forming process described above, the end portion may be passed through one or more pairs of rollers which provide the desired tapered cross section. This could be a wedge-shaped cross section, for example. It is preferred that the end section is formed by several rolling processes, i.e. rolling steps. Compared to a single rolling step, this reduces the load on the metal strip and the rollers, which is beneficial for the durability of the exchanger tube and reduces roller wear. Additionally, rolling the end introduces energy into the metal strip, which can facilitate the flow of brazing material during the brazing process.

Preferably, a stop portion is formed on the inner rib and the inner rib is disposed between the side wall portions such that the rear rib portion engages the rear portion and the stop portion engages the inner front portion such that the inner rib is elastically compressed and between the rear section and the inner front section is held. A possible position and shape of the stop section were described above in relation to the exchanger tube according to the invention. During the assembly process, when the inner rib is positioned between the first sidewall portion and the second sidewall portion, the rear rib portion is positioned in contact with the rear portion of the outer shell while the stop portion is positioned in contact with the inner front portion. One could also say that the rear section and the inner front section serve as stops for the inner rib. The dimensions are adjusted such that the described positioning of the rear rib section and the stop section is only possible by elastically compressing the inner rib in a direction that corresponds to the longitudinal direction of the assembled exchanger tube. This elastic deformation can be largely facilitated by a corrugated structure of the central rib section.

One embodiment provides that at least one cutting operation is carried out on the exchanger tube after the outer shell has been closed. According to a common method, the first metal strip is a part of an endless sheet or metal strip which is passed in the transverse direction through a sequence of roll forming stations. A certain length of the endless sheet corresponds to a single exchanger tube. Once all rolling steps for the respective length of sheet have been carried out, the metal strip is cut from the endless sheet. The corresponding cutting operation, which of course includes cutting the outer shell and the inner rib, is a critical operation which places considerable stress on the material. It is of great advantage in this step that the front rib section is received between the front sections of the outer shell and that the spring section is clamped by the outer front section, both of which assist in maintaining the correct relative positions of these elements.

Brief description of the drawings

• 1: eine perspektivische Ansicht eines erfindungsgemäßen Wärmetauschers;
• 2: eine erste perspektivische Ansicht eines erfindungsgemäßen Tauscherrohrs;
• 3: eine Seitenansicht des Tauscherrohrs von 2;
• 4: eine Detailansicht von 3;
• 5: eine Seitenansicht des Tauscherrohrs von 2 in einer ersten Stufe eines Herstellungsverfahrens;
• 6: eine Seitenansicht des Tauscherrohrs von 2 in einer zweiten Stufe des Herstellungsverfahrens; und
• 7: eine Seitenansicht des Tauscherrohrs von 2 in einer dritten Stufe des Herstellungsverfahrens.

Preferred embodiments of the invention will now be described by way of example with reference to the accompanying drawings. Show it:

• 1 : a perspective view of a heat exchanger according to the invention;
• 2 : a first perspective view of an exchanger tube according to the invention;
• 3 : a side view of the exchanger tube from 2 ;
• 4 : a detailed view of 3 ;
• 5 : a side view of the exchanger tube from 2 in a first stage of a manufacturing process;
• 6 : a side view of the exchanger tube from 2 in a second stage of the manufacturing process; and
• 7 : a side view of the exchanger tube from 2 in a third stage of the manufacturing process.

Description of preferred embodiments

1 illustrates a heat exchanger 1 according to the invention, which can be used as a radiator in a vehicle such as a passenger car or truck. The heat exchanger 1 can in particular be a condenser in which an initially gaseous fluid is condensed into the liquid state. The heat exchanger 1 comprises a first distributor or first container 2, which is connected to a second distributor or second container 9 via an exchanger core 8. The first container 2 and the second container 9 each have an approximately cylindrical shape and are elongated along a first axis Z, which is a vertical axis of the vehicle. Both containers are closed at both ends by respective end walls.

The exchanger core 8 extends along a vertical direction Z (which corresponds to the height axis of the vehicle) and along a transverse direction Y (which corresponds to the transverse axis of the vehicle).

The interior of the first vessel 2 is divided by a partition wall 7 into an inlet vessel cavity 3 and an outlet vessel cavity 4. The inlet vessel cavity 3 communicates with an inlet pipe 5 through which it receives a gaseous fluid during operation of the heat exchanger 1. The fluid is then distributed to a lower part of the exchanger core 8 and led into the second vessel 9. It is distributed from there to an upper part of the exchanger core 8 and led to the outlet vessel cavity 4 which communicates with an outlet pipe 6. It is understood that the fluid condenses on its way from the inlet vessel cavity 3 to the outlet vessel cavity 4. The exchanger core 8 comprises a plurality of exchanger tubes 10, one of which is in 2-7 is shown and will now be described.

2 shows a perspective view of the exchanger tube 10 (or condenser tube), while 3 and 4 Show side views. The exchanger tube 10 extends along the transverse direction Y, which corresponds to the flow direction of the fluid during operation. The exchanger tube 10 is countersunk right to the transverse direction Y has a cross section which is elongated in the longitudinal direction X relative to the vertical direction Z. In other words, this means that the exchanger tube 10 can be referred to as a flat exchanger tube. It comprises an outer jacket 20 made from a single first metal strip 21, which consists of an aluminum sheet coated with a brazing material. The outer jacket 20 surrounds an inner cavity 40. An inner rib 30 (or a turbulator) is arranged inside the inner cavity 40. Similar to the outer jacket 20, the inner rib 30 is made from a single second metal strip 31, which consists of an aluminum sheet; the second metal strip may, in embodiments, be provided with plating on the surface - usually on both sides. However, the thickness (or strength) of the second metal strip 31 only corresponds to approximately 30-40% of the thickness of the first metal strip 21.

The outer casing 20 includes a first side wall section 23 and a second side wall section 25, both of which extend parallel to the longitudinal direction X and are spaced apart along the vertical direction Z. The distance between the side wall sections 23, 25 defines a height of the inner cavity 40. The first side wall section 23 is arranged on a vertically first side U (or upper side), while the second side wall section 25 is arranged on a vertically second side L (or lower side ) is arranged. On a longitudinally rear side R, the side wall sections 23, 25 are connected by an arcuate, convex rear section 24 of the first metal band 21. On a longitudinal front side F, an inner front portion 22 of the band 21 extends from the first side wall portion 23 to the second side L and an outer front portion 26 of the band 21 extends from the second side wall portion to the first side U.

Like best in 4 As can be seen, the inner front section 22 includes an oblique section 22.1 (or a bend) which is inclined towards the second side L at an angle of approximately 60 ° with respect to the first side wall section 23. The oblique section 22.1 merges into an inner convex section 22.2, which has an arc shape and corresponds to an arc of approximately 180°. A convex subsection 22.5 is arranged at the transition between the first side wall section 23 and the inclined section 22.1, while a concave subsection 22.6 is arranged at the transition between the inclined section 22.1 and the inner convex section 22.2. Compared to the oblique section 22.1, the inner convex section 22.2 is connected to a leg section 22.3, which in the assembled state is essentially parallel to the longitudinal direction X. It should be noted that the inner front portion 22 with the convex portion 22.2 and the leg portion 22.3 also forms a locking feature that cooperates with one end of the inner rib 30, thereby keeping the inner rib 30 in an intermediate assembly state shown in FIG 4 is shown, can remain in place along the first side wall section 23. The outer front section 26 almost completely overlaps the inner front section 22 on the outside (with respect to the inner cavity 40). It includes an outer convex section 26.1 with an end section 26.2 at its end. The end section 26.2, which has a wedge-shaped cross section with a wedge angle of 60°, is in contact with the oblique section 22.1, while a part of the outer convex section 26.1 engages the inner convex section 22.2 from the first side U. The inner convex section 22.2 and the leg section 22.3 are parts of a spring section 22.4. While the outer front section 26 engages the spring section 22.4 directly from the first side U, it also engages the spring section 22.4 indirectly from the second side L via a front rib section 32. The front rib section 32 is arranged and received between the inner convex section 22.2 and the outer convex section 26.1 and between the leg section 22.3 and the second side wall section 25. The spring section 22.4 is thus effectively clamped along the vertical direction Z. On the first side U of the front rib section 32, the inner convex section 22.2 and the outer convex section 26.1 are separated by a gap 41 which tapers towards the first side U.

It is understood that the first metal strip 21 is initially normally a rectangular sheet, whereby the inner and outer sections 22, 26 with their respective convex sections 22.2 and 26.1 are formed in the longitudinal edge sections (or edge regions) of the metal strip 21.

During operation of the vehicle, the front side F corresponds to the direction of travel, which is why sand and other particles usually hit the exchanger tube 10 from this side. Accordingly, the exchanger tube 10 has a multi-layer structure on the front side F with three layers on the second side L and two layers with the space arranged therebetween on the first side U. The three-layer structure provides improved stability, while the two-layer structure with the space therebetween allows some deformation of the outer front section 26 that is independent of the inner front section 22. Accordingly, it is unlikely that any particles that strike the exchanger tube 10 from the front side F will penetrate the outer jacket.

The inner rib 30 extends from the front rib portion 32 to a rear rib portion 34 which engages the rear portion 24 of the outer shell 20. It also includes a corrugated central rib portion 33 which is in contact with both side wall portions 23, 25 and is connected thereto by brazing. The central rib section 33 divides the inner cavity 40 into a plurality of sub-cavities 40.1, each of which corresponds to a separate fluid channel through the exchanger tube 10, corresponding to a multi-channel configuration.

A method for producing the exchanger tube 10 will now be based on 5 to 7 explained. The outer jacket 20 and the inner rib 30 can be produced by passing the respective metal strip 21, 31 through a series of profile rolling stations. The roll forming stations are arranged one behind the other along a direction corresponding to the transverse direction Y, and the metal strip 21, 31 is transported along this direction. At each profile rolling station, one or more rollers act on the metal strip 21, 31, whereby its profile gradually changes into the in 5 the shape shown is bent. The wedge-shaped cross section of the end section 26.2 is also formed by one or more rolling processes. 5 shows a state of the method in which the side wall sections 23, 25 are not parallel but at an angle to one another and the profile of the outer jacket 20 is open. Accordingly, the inner rib 30 can be easily inserted between the side wall sections 23, 25.

In order to maintain the correct position of the inner rib 30 during the further assembly process, the stop section 33.1 is brought into contact with the leg section 22.3 of the inner front section 22. This occurs simultaneously with an elastic compression of the inner rib 30 or in particular the central rib section 33. Since the stop section 33.1 is at an angle of approximately 80° with respect to the first side wall section 23 (which corresponds to the longitudinal direction X when assembled), it is held in place by friction and does not slide off the inner front section 22.

While the inner rib 30 is clamped between the rear section 24 and the inner front section 22, the outer shell 20 is closed by folding the side wall sections 23, 25 into a shape as in 7 parallel position shown can be moved. Since the inner convex portion 22.2 and the leg portion 22.3 are moved toward the outer convex portion 26.1 and second side wall portion 25, the front rib portion 32 is deformed into a curved shape. In this state, the outer convex section 26.1 and the end section 26.2 are not yet in contact with the inner convex section 22.2 and the oblique section 22.1.

In a final formation step, the outer front section 26 is formed into the 3 and 4 The spring portion 22.4 is now elastically deformed because it is engaged by the outer front portion 26 from the first side U. This elastic deformation, which results in a prestress of the spring portion 22.4, ensures close contact between the spring portion 22.4, the outer front portion 26 and the front rib portion 32. Normally, the forming steps described above are carried out on a continuous sheet and then a length corresponding to the transverse dimension of the exchanger tube 10 is cut from the continuous sheet. It is very advantageous in this cutting process that the relative positions of the outer shell 20 and the inner rib 30 are secured as described above. Furthermore, the structure of the exchanger tube 10 is also stabilized by the corrugated shape of the central rib portion 33. Finally, the entire exchanger tube 10 is subjected to an elevated temperature which melts the brazing material, thereby joining the central fin portion 33 to the side wall portions 23, 25. At the same time, the front fin portion 32 is joined to the leg portion 22.3, the inner convex portion 22.2, the outer convex portion 26.1 and the second side wall portion 25. In addition, the end portion 26.2 is joined to the oblique portion 22.1 and a part of the outer convex portion 26.1 is joined to the inner convex portion 22.2.

Notes on construction and assembly procedures

The design of the exchanger tube according to the invention allows the tube to be formed at an angle and over several rolling stations, thereby reducing the so-called "profile roll wear".

Rolling is therefore advantageous for the realization of the end section 26.2 of the outer section 26, which requires a reduction in thickness and taper.

In addition, rolling the end introduces energy into the pipe, which acts as a catalyst for the The present design also allows for better overlap of the material because there are no acute angles in the overlap area. This creates almost no gap between the inner convex section 22.2 and the outer convex section 26.1 on the side of the bevel section 22.1. However, to ensure that the two features remain in close contact during brazing, the overlap of the inner convex section 22 and the outer convex section 26 is held in tension by the spring design of section 22.4. The spring section 22.4 is rolled into the tube and provides the tension between the inner and outer convex sections. It keeps the inner tube compressed against the outer tube surface. The spring feature 22.4 is advantageously oversized by a few percent, for example 5 to 10%, in the early roll forming stations so that it can hold the inner tube wall pressed against the outer surface.

The inner rib 30 is pressed into place when it is mounted on the tube and hooks onto the inner front section 22 on the spring 22.4 / the leg section 22.3. This helps hold the inner rib 30 in place like a compressed spring because the two side walls 23 and 25 are rolled together until the spring section 22.4 is finally hooked into the outer front section 26.

In the final roll forming stations, the inner and outer sections 22, 26 of the tube are rolled until the outer section 26 encloses the inner section 22, at which point the tube surfaces are bonded together and the inner rib 30 is locked in place. The spring section 22.4 maintains contact between the inner and outer sections while ensuring a small gap of 0 to 0.5 mm between them. However, the inner rib 30 should preferably not extend beyond the centerline of the tube to control the gap thickness. In addition, the inner rib preferably does not extend too far backwards so that the tensile stress on the spring feature 22.4 is maintained. The end section 26.2 should preferably not extend further backwards beyond the bending radius so that the spring effect on the design feature 22.4 is maintained.

List of reference symbols:

1

Heat exchanger

2

first container

3

Inlet container cavity

4

Outlet container cavity

5

inlet pipe

6

outlet pipe

7

partition wall

8th

exchanger core

9

second container

10

exchanger tube

20

Outer jacket

21

first metal band

22

inner front section

22.1

oblique section

22.2

inner convex section

22.3

leg section

22.4

Spring section

22.5

convex subsection

22.6

concave subsection

23

first side wall section

24

rear section

25

second side wall section

26

outer front section

26.1

outer convex section

26.2

End section

30

inner rib

31

second metal band

32

front rib section

33

middle rib section

33.1

stop section

34

posterior rib section

40

inner cavity

40.1

sub-cavity

41

space

F

front side

L

second page

R

rear side

U

first page

X

Longitudinal direction

Y

Transverse direction

Z

Vertical direction

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2012106242 A2 [0006]
• US 20170144212 A1 [0006]
• EP 3399267 A1 [0006]
• US 20070095514 A1 [0006]
• DE 102008052785 A1 [0006]

Claims (17)

Exchanger tube (10) for a heat exchanger (1) which extends in a transverse direction (Y) with a cross section perpendicular thereto which is elongated in a longitudinal direction (X) with respect to a vertical direction (Z), the exchanger tube (10) The following includes: - an outer jacket (20) which is formed from a single first metal strip (21) and surrounds an inner cavity (40), the outer jacket (20) comprising: a first side wall section (23) on a vertically first side (U) and a second side wall portion (25) on a vertically second side (L) extending in the longitudinal direction (X) and spaced apart in the vertical direction (Z), a rear portion (24) comprising the side wall portions (23, 25). on a longitudinally rear side (R), an inner front section (22) extending from the first side wall section (23) on a longitudinally front side (F) towards the second side (L), and an outer front section ( 26), which extends from the second side wall section (25) on the front side (F) towards the first side (U) and at least partially overlaps with the inner front section (22), the inner front section (22) being a inner convex portion (22.2) and the outer front portion (26) includes an outer convex portion (26.1) disposed outwardly from the inner convex portion (22.2) with respect to the inner cavity (40); and - an inner rib (30), which is formed from a single second metal strip (31), is arranged at least largely within the outer jacket (20) and extends from a rear rib section (34) to a front rib section (32), which is at least partially between the inner front section (22) and the outer front section (26), the outer front section (26) having a spring section (22.4), which includes the inner convex section (22.2), from the first side ( U) engages and engages the spring section (22.4) from the second side (L) via the front rib section (32) arranged therebetween, whereby the spring section (22.4) is clamped in the vertical direction (Z). exchanger tube Claim 1 , wherein the spring section (22.4) is elastically compressed in the vertical direction (Z). Exchanger tube according to any one of the preceding claims, wherein the inner front section (22) comprises an inclined section (22.1) adjacent to the inner convex section (22.2), the inclined section (22.1) extending from the first side wall section (23) to the second side ( L) is inclined, whereby the inner convex section (22.2) is offset from the first side wall section (23) towards the second side (L), and an end section (26.2) of the outer front section (26) is on the first side ( U) is arranged relative to the inner convex section (22.2). exchanger tube Claim 3 , wherein the inclined section (22.1) has an inclination of less than 70 ° with respect to the first side wall section (23). exchanger tube Claim 3 or 4 , wherein the end section (26.2) comprises a tapering cross section carried out by at least one rolling process and is arranged adjacent to the oblique section (22.1). exchanger tube Claim 5 , wherein the tapered cross section is a wedge-like cross section with a wedge angle of less than 70°. Exchanger tube according to any one of the preceding claims, wherein the outer front section (26) is flush with the first sidewall section (23) with respect to the vertical direction (Z). An exchanger tube according to any one of the preceding claims, wherein the front rib portion (32) is joined to the inner front portion (22) and the outer front portion (26). Exchanger tube according to any of the Claims 3 until 8th , wherein the end section (26.2) of the outer front section is joined to the inclined section (22.1). Exchanger tube according to any one of the preceding claims, wherein the front rib section (32) extends in the vertical direction (7) over 30-60% of a height of the inner cavity (40) defined by a distance between the side wall sections (23, 25) in the vertical direction (Z). ) extends and the inner front section (22) and the outer front section (26) are separated by a gap (41) on the first side (U) relative to the front rib section (32). Exchanger tube according to any one of the preceding claims, wherein the inner front section (22) comprises a leg section (22.3) adjacent to the inner convex section (22.2), the front rib section (32) at least partially between the leg section (22.3) and the second side wall section (25) is included. exchanger tube Claim 11 , wherein the leg section (22.3) is straight and extends parallel to the second side wall section (25). An exchanger tube according to any one of the preceding claims, wherein the rear rib portion (34) engages the rear portion (24) in the longitudinal direction (X). Exchanger tube according to any one of the preceding claims, wherein the inner rib (30) comprises a central rib section (33) between the rear rib section (34) and the front rib section (32), the central rib section (33) being at least partially corrugated and in contact with both side wall sections (23, 25). Exchanger tube according to any one of the preceding claims, wherein the central rib section (33) is joined to both side wall sections (23, 25). Exchanger tube according to any one of the preceding claims, wherein the inner rib (30) comprises a stop section (33.1) which is arranged near the inner front section (22) and extends in the vertical direction (Z) over at least 50% of the height of the inner cavity ( 40), the stop section (33.1) extending at least partially at an angle of more than 60 ° with respect to the longitudinal direction (X). Heat exchanger (1), comprising: - a first container (2) and a second container (9) for a fluid, each extending in a vertical direction (Z), the first container (2) defining an inlet container cavity (3) and one of the containers (2, 9 ) defines an outlet container cavity (4); and an exchanger core (8) adapted to heat exchange the fluid with ambient air and comprising a plurality of exchanger tubes (10) according to any one of the preceding claims, wherein the exchanger tubes are adapted to transfer a fluid from the inlet container cavity (3) to the outlet container cavity (4 ) to guide.

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