Profile for tube sheet, tube sheet and cooler for automotive air conditioning system

Abstract

To provide a profile for a tube sheet, a tube sheet, and a cooler that are more resistant to thermal shocks.SOLUTION: The invention relates to: a profile (10) for a tube sheet of a cooler with a cross-sectional shape between slots of tubes which have at least two wave troughs (12); a tube sheet with such a profile; and a cooler comprising the tube sheet; where the cooler further comprises many parallel tubes.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a profile for a tube sheet of a cooler, a tube sheet having such a profile, and a cooler having at least one tube sheet, in particular for an automotive air conditioning system.

[0002] Automotive coolers typically comprise a number of parallel tubes, in particular flat tubes, through which a coolant flows. Such a flow occurs in particular between two so-called tube sheets, which have suitable slots into which a large number of tubes are inserted, and the large number of tubes are soldered to the tube sheets.

[0003] Such connection points are subject to particular loads especially when the coolant temperature changes rapidly. In this case, a significant temperature difference occurs between the individual tubes, causing the tubes to expand differently, which results in a significant load at the connection points between the tubes and the tube sheets. Thus, damage occurring in such areas is due to so-called thermal shock.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Against this background, it is an object of the present invention to provide a profile, a tube sheet and a cooler which are more resistant to thermal shock.

Means for Solving the Problems

[0005] The above object is solved on the one hand by a profile according to claim 1. Thereby, the profile has a cross-sectional shape between the slots of the tubes having at least two wave troughs. As a result, the stress distribution is improved in the case of the above-mentioned loads so that the resistance to thermal shock is significantly improved. The results of initial tests showed a thermal shock resistance improved by a factor of two to three.

[0006] Preferred embodiments are described in the dependent claims.

[0007] When there is a web peak with two web troughs placed therebetween, even if it is sufficient to fix the tube "doubly" substantially by the two web troughs and the tube slot extends between the two web troughs, it is preferable to provide at least three web peaks. That is, this means that an additional web peak is connected to each web trough. Here, it must be mentioned that the web trough extends in the direction of the tube and the web peak extends in the direction of the tube sheet or inside the cooler tank provided with the tube sheet. When three web peaks are provided, the tube slot extends from the two outer surfaces to at least the highest point of the outer web peak.

[0008] It has been found that it varies by the design of the individual radius of the web through extensive testing. The values given below apply to the width of flat tubes from 14 to 37 mm and / or the material thickness of the profile according to the invention of 1 to 2 mm, in particular about 1.5 mm and / or the tangential spacing of the web troughs and peaks of about 4 to 6 mm. Thus, with regard to the radius, the values according to claims 3 and 4 are preferred, in which case it has been found that there is a particularly firm connection between the tube sheet having the profile according to the invention and the flat tube. Considering different radii, such a radius is always measured inside the profile, i.e., on the opposite side of the tube, and it must be mentioned that the outer or external radius indicates a radius closer to the outside of the profile when the outside means the position where the web (progressing across the profile) starts. Here, it must be mentioned that the cross-sectional shape of the profile is typically symmetric with respect to the center in the mentioned web progression direction.

[0009] Also, it has been found that in the research scope, when there is at least one flattening portion in at least one web peak or trough, it is even more advantageous for the sustainable resistance to thermal shock.

[0010] In a wide range of research, the general formula according to claim 6 was determined for the width of such a flattening portion. In this case, it should be emphasized that only one of the values of W1 to W4 should be satisfied, which is similarly applicable to one or more of the radii of R1 to R5.

[0011] In the manner mentioned, the profile according to the invention can be made of aluminum or an aluminum alloy.

[0012] This is preferably also similarly applicable to a number of tubes soldered to at least one profile, in particular flat tubes.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0014] As shown in Fig. 1, the profile (10) of the present invention for the tube sheet of the cooler has the form of a flat shell with a long, extended rectangular shape and rounded corners and edges. On the upper surface according to Fig. 1, the profile (10) shown is closed by additional profiles, and as a result, a tube sheet that is typically vertically aligned during operation is manufactured. Under the profile (10) shown in Fig. 1, in the orientation of Fig. 1, and typically in a horizontal mounting state, a number of flat tubes are inserted into slots (16) formed at the "bottom" of the profile (10). The present invention is mostly related to the cross-sectional shape of the bottom maintained between the slots (16). The dimensions of the bottom section maintained in the direction from the lower left to the upper right according to Fig. 1 are slightly larger than the dimensions of the slots (16) in the same direction, particularly 1.5 to 2.5 times larger.

[0015] In Fig. 2, not only the web form of the bottom but also additional webs (18) surrounding the periphery are shown. At this time, the webs each surround the respective slots (16) and have a form corresponding to the form of the flat tubes to be inserted basically. As can be seen more clearly in Fig. 6, the webs (18) have a considerable, preferably constant height (H) over the circumference, and such a height reliably ensures a soldering connection with the flat tubes to be inserted. The slots (16) and the webs (18) are typically formed by a burring process.

[0016] Fig. 2 shows the web form of the profile (10) of the present invention already between the slots (16). The web form has two web troughs (12) and three web peaks (14) facing the side of the flat tubes (not shown) in the example shown. The slots (16) extend approximately to the highest points of the two outer web peaks (14).

[0017] Figure 2 shows a profile for a flat tube having a width of 18.5 mm (measured from left to right in Figure 2), Figure 3 shows a profile for a width of 14 mm, Figure 4 shows a profile for a flat tube width of 25.2 mm, and Figure 5 shows a profile for a flat tube width of 36.4 mm. As shown in Figure 3, here the web is somewhat flatter, and in the embodiments according to Figures 4 and 5 the web peaks are explained in more detail and disassembled with reference to Figures 7 and 8 as follows.

[0018] Figure 6 shows radii (R1 to R5), but in this case it must be emphasized that the radii are always measured on the opposite side of the flat tube (not shown). In this regard, the outer or external radius means the radius measured on the (lateral) outside, i.e., on the left side in relation to the first web peak (14.1) in Figure 6. In contrast, the inner or internal radius is measured at a position continuously placed inside (continuously on the right side in Figure 6), such as R2 in the case of the first web peak (14.1) and R4 in the case of the first web trough (12.1). Also, the profile cross-sectional form according to the present invention shown in Figure 6 is symmetric about the center of the second central web peak (14.2), and as a result, contrary to the described direction indication, it applies to the right half of the profile according to Figure 6. The preferred values for a flat tube with a width of 18.5 mm are R1 = 2.3 mm, R2 = 2.6 mm, R = 1.9 mm, R4 = R5 = 1.9 mm, and R5 = 4 mm.

[0019] Figure 7 shows the flattening portion presented in claim 6 and is shown with respect to the profile of Figure 6.

[0020] The profile of Figure 8 corresponds to the profile of Figure 4, and in this case, a wider planar section (W3) is provided to correspond to the preferred design.

Explanation of Reference Signs

[0021] 10 Profile 12 Web trough 12.1 First web trough 12.2 Second web peak 14 Web peak 14.1 First web peak 14.2 Second central web peak 14.3 Third web peak 16 Slot 18 Web

Claims

1. a profile (10) for a tube sheet of a cooler, the cooler further comprising a number of parallel tubes, the tube sheet having a cross-sectional shape between the tube slots having at least two web troughs (12); At least three web peaks (14) are further provided; From the outside to the inside, the outer radius (R1) of the first web peak (14.1), the inner radius (R2) of said first web peak (14.1), the outer radius (R3) of the first web trough (12.1), the inner radius (R4) of said first web trough (12.1) and the radius (R5) of the second web peak (14.2) are as follows: R1=1.5~3.5mm, R2=2 to 4 mm, R3=1.9~5mm, R4=1.9~40mm, R5 is measured at 3 to 50 mm. The at least two web troughs (12) and the at least three web peaks (14) are also formed between the slots and are formed over the entire area of ​​the bottom of the tubesheet profile (10), the at least three web peaks (14) including two outer web peaks (14), the slots extend to the highest points of the two outer web peaks (14), and the slots are formed by burring.

2. 2. A tubesheet profile according to claim 1, characterized in that at least one web peak (14) or trough (12) has at least one flattening portion.

3. The following formula applies to at least one flattening section (W1) on a first web peak (14.1) from the outside to the inside, at least one flattening section (W2) between said first web peak (14.1) and a first web trough (12.1), at least one flattening section (W3) within said first web trough (12.1) and at least one flattening section (W4) between said first web trough (12.1) and a second web peak (14.2):

3. The tubesheet profile of claim 2, wherein alpha (α) is the angle between the first web trough (12.1) and the second web peak (14.2) relative to a tangent to the first web trough (12.1), Twidth is the tube width, and R1-R5 are the outer radius (R1) of the first web peak (14.1), the inner radius (R2) of the first web peak (14.1), the outer radius (R3) of the first web trough (12.1), the inner radius (R4) of the first web trough (12.1) and the radius (R5) of the second web peak (14.2).

4. 4. A tubesheet profile according to claim 1, characterized in that the tubesheet profile is made of aluminum or an aluminum alloy.

5. Tube sheet, characterized in that it comprises at least one tube sheet profile according to any one of claims 1 to 4.

6. A cooler for an automotive air conditioning system, comprising at least one tube sheet according to claim 5.

7. 7. A cooler for an automotive air conditioning system according to claim 6, characterized in that said tubes are made of aluminum or an aluminum alloy and are soldered to at least one tube sheet profile.

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