DE102020201556A1 - Inner rib and flat tube with an inner rib - Google Patents

Abstract

The invention relates to an inner rib (7), in particular for a flat tube (1), in particular a heat exchanger, made of a metallic flat strip which is shaped in a wave-like manner with a plurality of wave crests (8) and wave troughs (9), each alternating in a longitudinal direction of the inner rib (7), with a substantially straight, web-like rib region (10) being provided between a wave crest (8) and an adjacent wave trough (9), which connects the wave crest (8) with the wave trough (9) , the metallic flat band having a first band thickness L1 which is essentially constant in the area of the wave crests (8) and the wave troughs (9), the flat metallic band having a second band thickness L2 which is in the area of the web-like rib area (10 ) is formed, where L2 is smaller than L1.

Description

Technical area

The invention relates to an inner fin and a flat tube with an inner fin, in particular for a heat exchanger, in particular for a motor vehicle.

Background of the invention

In heat exchangers for motor vehicles, flat tubes are known in which an inner rib is pushed or inserted into the tube interior of the flat tube, which rests on the opposite broad sides of the flat tube and are soldered there so that the flat tube has increased internal pressure resistance. For this purpose, the inner rib is, for example, modulated in a wave-like manner with a large number of wave crests and wave troughs, which are each alternately soldered adjacent to the broad sides of the flat tube.

The inner rib improves the internal pressure resistance of the flat tube and also increases the heat transfer rate from a first fluid flowing through the flat tube to a second fluid flowing around the flat tube, or vice versa.

Modern motor vehicles are increasingly being optimized for low consumption values and / or low emissions. This applies in particular to vehicles with internal combustion engines. However, the focus on low consumption values is also very relevant for electric vehicles or hybrid vehicles, since in particular the low consumption of electrical energy per kilometer driven is cost relevant for driving the motor vehicle and also determines the maximum range of the motor vehicle.

In this context, however, it can be seen that the flat tube is the focus with regard to the cost and weight of the heat exchanger due to its very frequent use in a heat exchanger.

Presentation of the invention, task, solution, advantages

It is the object of the invention to create an inner fin which, compared to the prior art, allows good heat transfer with a flat tube with a good internal pressure resistance at the same time, and which can nevertheless be produced cost-effectively with reduced material usage. It is also the task to create a flat tube with an inner rib which is inexpensively strengthened with less use of material and yet has good internal pressure resistance with good heat transfer.

The object relating to the inner rib is achieved with the features of claim 1.

One embodiment of the invention relates to an inner rib, in particular for a flat tube, in particular a heat exchanger, made of a metallic flat strip, which is shaped in a wave-like manner with a plurality of wave crests and wave troughs, which are each arranged alternately in a longitudinal direction of the inner rib, with between a Wave crest and an adjacent wave trough a substantially straight, web-like rib area is provided which connects the wave crest with the wave trough, wherein the metallic flat band has a first band thickness L1, which is essentially constant in the area of the wave crests and the wave troughs, the flat metallic band has a second band thickness L2, which is formed in the area of the web-like rib area, where L2 is smaller than L1. As a result, material is saved in an intermediate area between the wave crests and the wave troughs to such an extent that a significant weight reduction is achieved while the internal pressure resistance and heat transfer are still sufficiently good.

In one embodiment, it is advantageous if the metallic flat band has a first band thickness L1, which is essentially constant in the entire region of the wave crests and the wave troughs, and that the flat metallic band has a second band thickness L2, which is essentially entire area of the web-like rib area is formed. As a result, material is saved in the entire intermediate area between the wave crests and the wave troughs to such an extent that a significant weight reduction is achieved while the internal pressure resistance and heat transfer are still sufficiently good.

It is particularly advantageous if the metallic flat strip is curved in the region of the wave crests and the wave troughs. As a result, the area of the connection to the flat tube can be made in the curved area, advantageously by soldering.

It is particularly advantageous if the strip thickness reduction R from the first strip thickness L1 to the second strip thickness L2 takes place in a range from 0.2 * L1 to 0.9 * L1, i.e. 0.2 * L1 <L2 <0.9 * L1, in particular 0.3 * L1 <L2 <0.7 * L1 or more particularly 0.35 * L1 <L2 <0.55 * L1 or more particularly L2 = 0.5 * L1 applies. This achieves the intended goals with regard to internal pressure resistance, material savings and also with regard to improving the pressure drop in the pipe interior.

It is also useful in a further embodiment if the metallic flat strip has two opposite broad sides, between which the strip thickness can be determined, the strip thickness reduction R being made from the first strip thickness L1 to the second strip thickness L2 on at least one broad side of the flat strip or is made on both opposite broad sides of the flat strip. An asymmetrical or a symmetrical stiffness behavior can thus be achieved, the arrangement of the strip thickness reduction also depending on the production of the strip thickness reduction, for example by rolling the metallic strip.

In a further embodiment, it is also expedient if the strip thickness reduction R from L1 to L2 is carried out on both opposite broad sides of the flat strip by a constriction, with approximately the same proportional strip thickness reduction on both broad sides R1 , R2 of about R1 = (L1-L2) / 2 and R2 = (L1-L2) / 2. In this way, a favorable force distribution is achieved with the desired reduction in material.

It is also advantageous if the strip thickness reduction R from L1 to L2 is present on both sides of the neutral fiber of the strip, in particular on both sides of the neutral fiber about the same proportional strip thickness reduction in terms of amount R1 , R2 of about R1 = (L1-L2) / 2 and R2 = (L1-L2) / 2. This also results in a favorable distribution of force with the desired reduction in material.

It is also advantageous if the metallic flat strip has a first strip thickness L1, which is essentially constant in the entire area of the wave crests and troughs, and that the flat metallic strip has a second strip thickness L2, which is essentially in the entire area of the web-like rib region is formed. In this way, a favorable force distribution is achieved with the desired reduction in material.

The object relating to the flat tube is achieved with the features of claim 9.

One embodiment of the invention relates to a flat tube with a tube wall and a tube interior, the tube wall having two opposite broad sides and two opposite narrow sides, an inner rib according to the invention being arranged in the tube interior, the corrugation peaks on one of the two broad sides of the tube wall and the corrugation troughs rest on the other of the two broad sides, in particular the wave crests are connected to one of the two broad sides of the pipe wall and the wave troughs are connected to the other of the two broad sides, in particular are soldered, welded or glued.

In an exemplary embodiment, it is advantageous if the wave crests are soldered on one of the two broad sides of the pipe wall and the wave troughs on the other of the two broad sides, with soldering meniscuses formed from solder material between the strip and the broad sides, the web-like rib area having the second strip thickness L2 is arranged between the solder menisci.

Further advantageous refinements are described by the following description of the figures and by the subclaims.

Figure list

The invention is explained in more detail below on the basis of several exemplary embodiments with reference to the figures of the drawings.

• 1 eine schematische Schnittdarstellung eines Flachrohrs,
• 2 eine schematische Teilschnittdarstellung des Flachrohrs mit einer erfindungsgemäßen Innenrippe,
• 3 ein Ausschnitt des Schnitts der Innenrippe, und
• 4 ein weiterer Ausschnitt des Schnitts der Innenrippe.

Show it:

• 1 a schematic sectional view of a flat tube,
• 2 a schematic partial sectional view of the flat tube with an inner rib according to the invention,
• 3 a section of the section of the inner rib, and
• 4th Another section of the cut of the inner rib.

Preferred embodiment of the invention

the 1 shows a flat tube 1 with a pipe wall 2 and a pipe interior 3 in one cut. The pipe wall 2 is an example of a sheet metal strip 4th formed, which is deformed. So can the sheet metal strip 4th be designed as a folded tube and soldered, as shown, or alternatively the flat tube can also be designed as a welded tube.

The pipe wall 2 has two opposite broadsides 5 and two opposite narrow sides 6th which are arranged alternately around the circumference. The flat tube 1 is in the embodiment shown on one of the two narrow sides 6th closed, with an overlap of end regions of the sheet metal strip 4th are formed which overlap and are soldered there.

Inside the pipe 3 is an inner rib 7th arranged. The inner rib 7th is from one formed metallic flat strip, which is rolled, for example, to form its structure. For example, the metallic band made of aluminum, an aluminum alloy, steel, etc. is formed.

The inner rib 7th is formed in a wave-shaped modulated shape and has a wave structure which has a large number of wave crests 8th and wave troughs 9 trains. The multitude of wave crests 8th and wave troughs 9 are each alternating in a longitudinal direction of the inner rib 7th arranged, being between a wave crest 8th and a neighboring wave trough 9 a substantially straight, web-like rib area 10 is provided, which the wave crest 8th with the trough of the waves 9 connects. This creates a large number of adjacent web-like rib areas 10 formed the interior 3 of the flat tube 1 in fluid paths 11 subdivide. The web-like rib areas 10 be designed to be closed over a large area or with interruptions in order to allow a cross flow.

The wave crests 8th lie on one of the two broad sides 5 the pipe wall 2 and the wave troughs 9 are on the other of the two broad sides 5 on. The wave crests are advantageous and optional 8th with one of the two broadsides 5 the pipe wall 2 and the wave troughs 9 with the other of the two broadsides 5 connected, in particular soldered, welded or glued.

In a preferred embodiment, the wave crests are 8th on one of the two broad sides 5 the pipe wall 2 and the wave troughs 9 on the other of the two broad sides 5 soldered, being between the band of the inner rib 7th and the broadsides 5 of the flat tube 1 Solder meniscus 12th from solder material, as shown in 2 can be seen.

Here is the web-like rib area 10 between the solder menisci 12th , which on opposite broad sides 5 are formed, arranged. It's in the 1 and 2 to see that the wall thickness of the sheet metal strip 4th the pipe wall 2 of the flat tube 1 is significantly thicker than the wall thickness of the metallic flat band of the inner rib 7th , for example at least twice as thick, three times as thick or more.

On closer inspection of the inner rib 7th is in 2 to see that the metallic flat band of the inner rib 7th has a first band thickness L1, which is in the region of the wave crests 8th and the wave troughs 9 is provided and which is essentially constant.

Furthermore, the flat metallic band has the inner rib 7th a second band thickness L2, which is in the area of the web-like rib area 10 is formed, where L2 is smaller than L1.

In an advantageous embodiment, it is optional and expedient if the metallic flat band of the inner rib 7th has a first strip thickness L1, which is essentially in the entire region of the wave crests 8th and the wave troughs 9 is essentially constant, the flat metallic strip of the inner rib having a second strip thickness L2, which is essentially in the entire region of the web-like rib region 10 is formed essentially constant.

From the 2 it can be seen that the metallic flat band of the inner rib 7th in the area of the wave crests 8th and the wave troughs 9 is curved. The curvature can have a radius of curvature or assume a plurality of radii of curvature.

The transition from the first strip thickness L1 to the second strip thickness L2 takes place advantageously in the transition from the curved wave trough 9 to the essentially straight web-like rib area 10 and takes place advantageously in the transition from the curved wave crest 8th to the essentially straight web-like rib area 10 as in 2 can be seen.

The strip thickness reduction R takes place from the first strip thickness L1 to the second strip thickness L2 in a range from 0.2 * L1 to 0.9 * L1, so that 0.2 * L1 <L2 <0.9 * L1 applies. It is particularly advantageous if the strip thickness reduction R from the first strip thickness L1 to the second strip thickness L2 is in a range from 0.3 * L1 to 0.7 * L1, so that 0.3 * L1 <L2 <0.7 applies * L1 or further advantageous if the strip thickness reduction R from the first strip thickness L1 to the second strip thickness L2 is in a range from 0.35 * L1 to 0.55 * L1 and 0.35 * L1 <L2 <0.55 applies * L1. Furthermore, it can also be advantageous if L2 = 0.5 * L1.

A closer look reveals that the metallic flat band of the inner rib 7th two opposite broadsides 13th has, between which the strip thickness can be determined, the strip thickness reduction R from the first strip thickness L1 to the second strip thickness L2 on at least one broad side 13th of the flat band of the inner rib 7th is made or, as in the 2 until 4th shown on both opposite broadsides 13th of the flat band of the inner rib 7th is made.

According to the 2 until 4th is the strip thickness reduction R from L1 to L2 on both opposite broadsides 13th of the flat band of the inner rib 7th made by a constriction. This is optional on both broad sides 13th roughly the same proportional strip thickness reduction in terms of amount R1 , R2 of about R1 = (L1-L2) / 2 and R2 = (L1-L2) / 2.

Correspondingly, the strip thickness reduction R from L1 to L2 is on both sides of the neutral fiber 14th of the band of the inner rib 7th proportionally, especially on both sides of the neutral fiber 14th roughly the same proportional strip thickness reduction in terms of amount R1 , R2 of about R1 = (L1-L2) / 2 and R2 = (L1-L2) / 2. It is therefore true that R = R1 + R2.

Claims (10)

Inner rib (7), in particular for a flat tube (1), in particular a heat exchanger, made of a metallic flat strip, which is shaped in a wave-like modulated manner with a large number of wave crests (8) and wave troughs (9), each alternating in a longitudinal direction of the inner rib (7) are arranged, with a substantially straight, web-like rib region (10) being provided between a wave crest (8) and an adjacent wave trough (9), which connects the wave crest (8) with the wave trough (9), the metallic flat strip has a first strip thickness L1, which is essentially constant in the area of the wave crests (8) and the wave troughs (9), characterized in that the flat metallic strip has a second strip thickness L2, which in the area of the web-like rib area (10) is formed, where L2 is smaller than L1. Inner rib (7) Claim 1 , characterized in that the metallic flat band has a first band thickness L1, which is substantially constant in the entire area of the wave crests (8) and the wave troughs (9), and that the flat metallic band has a second band thickness L2 which is formed essentially in the entire area of the web-like rib area (10). Inner rib (7) Claim 1 or 2 , characterized in that the metallic flat band is curved in the area of the wave crests (8) and the wave troughs (9). Inner rib (7) Claim 1 , 2 or 3 , characterized in that the strip thickness reduction R from the first strip thickness L1 to the second strip thickness L2 takes place in a range from 0.2 * L1 to 0.9 * L1, thus 0.2 * L1 <L2 <0.9 * L1 applies , in particular 0.3 * L1 <L2 <0.7 * L1 or more particularly 0.35 * L1 <L2 <0.55 * L1 or more in particular L2 = 0.5 * L1 applies. Inner rib (7) Claim 1 , 2 , 3 or 4th , characterized in that the metallic flat strip has two opposite broad sides (13), between which the strip thickness can be determined, the strip thickness reduction R being made from the first strip thickness L1 to the second strip thickness L2 on at least one broad side (13) of the flat strip is or is made on both opposite broad sides (13) of the flat strip. Inner rib (7) Claim 5 , characterized in that the strip thickness reduction R from L1 to L2 is carried out on both opposite broad sides (13) of the flat strip by a constriction, with approximately the same proportional strip thickness reduction R1, R2 of approximately R1 = (L1 -L2) / 2 and R2 = (L1-L2) / 2 is present. Inner rib (7) Claim 5 or 6th , characterized in that the tape thickness reduction R from L1 to L2 is present on both sides of the neutral fiber (14) of the tape, in particular on both sides of the neutral fiber (14) approximately the same proportional tape thickness reduction R1, R2 of approximately R1 = (L1-L2) ) / 2 and R2 = (L1-L2) / 2 is present. Inner rib (7) according to one of the preceding claims, characterized in that the metallic flat band has a first band thickness L1 which is substantially constant in the entire area of the wave crests (8) and the wave troughs (9), and that the flat metallic band has a second band thickness L2, which is formed essentially in the entire area of the web-like rib area (10). Flat tube (1) with a tube wall (2) and a tube interior (3), the tube wall (2) having two opposite broad sides (5) and two opposite narrow sides (6), with an inner rib (7) in the tube interior (3) ) is arranged according to one of the preceding claims, the wave crests (8) resting on one of the two broad sides (5) of the pipe wall (2) and the wave troughs (9) resting on the other of the two broad sides (5), in particular the wave crests (8) ) are connected to one of the two broad sides (5) of the pipe wall (2) and the wave troughs (9) are connected to the other of the two broad sides (5), in particular are soldered, welded or glued. Flat tube (1) Claim 9 , characterized in that the wave crests (8) are soldered on one of the two broad sides (5) of the pipe wall (2) and the wave troughs (9) on the other of the two broad sides (5), with ( 5) Form solder menisci (12) from solder material, the web-like rib area (10) is arranged with the second strip thickness L2 between the soldering menisci (12).

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