Heat exchanger

Abstract

The invention relates to a heat exchanger (1) for a motor vehicle (7), comprising a first heat exchanger tube and at least one second heat exchanger tube (2, 2 '), the heat exchanger tube (2, 2') having a first tube end face (4), the first tube end face (4) being oriented towards a front face V of the motor vehicle (7), the first tube end face (4) having a height h1, and the first tube end face (4) having a height h2. An elastic body (3, 3 ', 3' ') is arranged on the first tube end side (4) over the length L1 of the first heat exchanger tube and the at least one second heat exchanger tube (2, 2'), characterized in that the elastic body (3, 3 ', 3' ') has a height h2, and the elastic body (3, 3', 3 '') fully covers the first tube end side (4) over the height h2.

Description

Technical Field

[0001] The invention relates to a heat exchanger for a motor vehicle and to a motor vehicle of the type according to the independent claims. Background Art

[0002] JP 2016 061 459 A discloses a universal heat exchanger having an elastomer arranged at the end side of a heat exchanger tube. The elastomer serves as a protection for the heat exchanger tube and is intended to protect the heat exchanger from flying objects, such as stones. The elastomer is cylindrically shaped, wherein the end side of the heat exchanger tube is bent outward. In this case, in a mathematical sense, the tube is shaped convexly (konkav) and the elastomer is shaped concavely (konvex) relatively. The elastomer therefore contacts the heat exchanger tube only on a small surface. In order to be able to achieve protection, the elastomer must therefore be designed to be large in order to adequately protect the tube height, and, in addition, due to the relatively small contact area between the elastomer and the heat exchanger tube, a particularly process-reliable connection must be achieved. Summary of the invention

[0003] The object of the present invention is to design a heat exchanger in such a way that protection of the heat exchanger tubes by means of an elastomer can be adequately achieved with a low material outlay and at the same time a firm contact can be produced between the elastomer and the heat exchanger tubes.

[0004] In contrast, the heat exchanger according to the invention having the features of the independent claim has the advantage that the elastomer has a large surface contact with the heat exchanger tube and can therefore be held particularly stably in its position. The material distribution is designed particularly advantageously. Thus, the entire tube end face of the heat exchanger tube is protected against flying objects, such as stones, even if they strike the end face obliquely. Thus, by means of the shape according to the invention of the elastomer, good protection of the heat exchanger can be achieved with an advantageous, low material investment.

[0005] Therefore, a heat exchanger according to claim 1 and the dependent claims, and a motor vehicle having a heat exchanger according to claim 1 and the dependent claims are now proposed.

[0006] The heat exchanger according to the invention is usually used in motor vehicles for the heat exchange of two different fluids, wherein the first fluid is ambient air and the second fluid comprises a liquid or gaseous coolant or refrigerant, depending on the purpose of the heat exchanger. The heat exchanger can be a coolant heat exchanger, which releases heat from a cooling circuit of a motor vehicle to the environment. In this case, the cooling circuit absorbs heat in the motor vehicle from a heat source, such as an internal combustion engine or a battery, or an electrical heat source, such as an electric motor or power electronics, and releases it again to the ambient air in the heat exchanger.

[0007] As a refrigerant heat exchanger, the heat exchanger can use a refrigerant in liquid or gaseous state to exchange heat with the ambient air, for example, releasing heat from an air conditioning circuit and / or absorbing heat from a heat pump circuit.

[0008] Usually, the heat exchanger is arranged in the front area of ​​the motor vehicle, and the driving wind and the ambient air generated during the driving of the motor vehicle flow through there. In slow driving or when the vehicle is stationary, an additional fan can assist the ambient air to flow through the heat exchanger.

[0009] The arrangement in the front area of ​​the motor vehicle carries a great risk that objects, for example, which are caught by other vehicles driving ahead or by the vehicle itself, can strike the heat exchanger at its front side V. For example, these can be stones or branches which enter through openings, such as the radiator grille, which is supposed to conduct ambient air to the heat exchanger, and subsequently cause damage to the heat exchanger, in particular to the heat exchanger tubes. Such damage can lead to disadvantageous deformations of the heat exchanger tubes, which, due to the heat exchange of the heat exchanger, can lead to rupture of the heat exchanger tubes as secondary damage.

[0010] The impinging objects can also directly damage the heat exchanger tubes, which damage leads to immediate leaks. As a result, coolant or refrigerant may escape from the heat exchanger, which may lead to operational failures of the motor vehicle and possible environmental damage. Therefore, appropriate protective measures are required for the heat exchanger tubes in order to protect them from flying objects.

[0011] The heat exchanger according to the invention consists of a first heat exchanger tube and at least one second heat exchanger tube. The heat exchanger tubes can be stacked on top of each other and can each have corrugated ribs between the heat exchanger tubes. The ends of the heat exchanger tubes usually lead into two collectors. The second fluid, which can exchange heat, is guided from the first collector via the heat exchanger tubes to the second collector. Here, the second fluid releases heat to the ambient air or absorbs heat. The corrugated ribs located between the heat exchanger tubes, which are in direct material contact with the heat exchanger tubes, increase the surface of the heat exchanger that can be used for heat transfer and are flowed through by the ambient air.

[0012] The heat exchanger tube can be formed as a flat tube, which is composed of two long tube wall sections in cross section and has a first tube end side and a second tube end side. Here, the long tube wall section is usually significantly longer than the first height h1 of the tube end side, which also corresponds to the height of the heat exchanger tube. The tube end side can be formed by an arcuate section. However, it can be proposed that these tube end sides have one or more straight sections, which transition to long tube wall sections through arcuate sections.

[0013] Flat tubes are usually made of thin sheets with a wall thickness d, wherein the sheets are made of a metal material, in particular an aluminum material. The sheets are closed by bending and subsequent brazing or welding. Therefore, there are usually no sharp-edged sections on the flat tubes in order to avoid stress peaks in the material.

[0014] The flat tubes can be thicker or thinner in their first height h1 depending on the second fluid with which heat can be exchanged. Flat tubes for coolants generally have a greater first height h1 than flat tubes for refrigerants.

[0015] The first tube end side of the heat exchanger tubes points toward the front side V of the motor vehicle and can have an elastomer over the axial length L1 of the first and second heat exchanger tubes, which can at least partially cover the respective first tube end side. Here, the respective first tube end side in the solution according to the invention is fully covered by the elastomer over the second height h2, i.e., so that the respective elastomer is in direct material contact over the entire second height h2. As a result, the respective elastomer follows the shape of the respective first tube end side and advantageously establishes a maximum surface contact. As a result, a particularly stable connection of the respective elastomer to the respective first tube end side is established in an advantageous manner according to the invention.

[0016] In a further advantageous embodiment, the heat exchanger has at least one third heat exchanger tube. Similar to the first and second heat exchanger tubes, the at least one third heat exchanger tube has an elastomer on the respective first tube end side, which is arranged with an axial length L2. The length L2 is different from the length L1 of the respective first and second heat exchanger tubes. Due to the different lengths of the elastomers on the heat exchanger tubes, the heat exchanger can be protected in a particularly advantageous manner with a small amount of material.

[0017] Depending on the installation of the heat exchanger in the motor vehicle, components of the heat exchanger may be shielded against flying objects. This may be, for example, a carrier in the motor vehicle or also a fan which is usually arranged in front of the heat exchanger. If these components shield the heat exchanger accordingly, the respective first tube end side may be implemented without an elastomer or, depending on the situation, with an elastomer.

[0018] In a further embodiment according to the invention, a fourth heat exchanger tube can be provided which does not have any elastomer at all. Such a fourth heat exchanger tube is shielded so that the elastomer can be completely omitted. As in the case of only partial application over the length L1, L2 of the heat exchanger tube, individual installation positions of the heat exchanger can be taken into account and thus material and costs can be saved in an advantageous manner.

[0019] The elastic body is arranged on the respective first tube end side so that the elastic body can be mathematically shaped concavely in a direction oriented toward the respective first tube end side and convexly toward a side facing away from the respective first tube end side.

[0020] In a further preferred embodiment, the respective elastomer has a continuous course in its elevation and thus forms a bulge which rises on the respective first tube end and particularly preferably reaches its maximum at a third height h3 of the respective elastomer.

[0021] In a further embodiment according to the invention, the respective elastomer occupies a second height h2 which corresponds to at least 80% of the respective first height h1 of the tube end face or at least 80% of the height of the heat exchanger tube.

[0022] In a further embodiment according to the invention, the third height h3 of the respective elastic body corresponds to at least three times the respective tube wall thickness d of the heat exchanger tube. Therefore, sufficient elastic material is arranged in the respective elastic body to effectively protect the respective first tube end side.

[0023] Thus, the particularly sensitive tip of the respective first tube end is protected with a particularly large amount of elastic material. However, the transition of the respective first tube end to the long tube wall section is protected with less elastic material, which is not a disadvantage, since the heat exchanger tube has a significantly better resistance in the transition due to the greater amount of tube material with respect to the collision direction and therefore requires less elastic material for protection.

[0024] In a further advantageous embodiment, the respective elastomer consists of a silicone material. The use of silicone has the advantage that the respective elastomer can be applied directly to the already installed heat exchanger. Thus, different lengths L1, L2 can also be realized in a simple manner on the respective first tube end side. The application can be automated, so that the desired application amount and thus the elastomer shape according to the invention can be realized. The applied silicone material can be dried directly on the heat exchanger and can therefore also adhere directly to the respective first tube end side in a particularly advantageous manner.

[0025] However, it is also possible to produce the respective elastomer separately in terms of its length and the required shape and to apply it to the respective first pipe end side after drying by means of a suitable adhesive.

[0026] It is also possible to use other suitable materials to shape the elastomer and to apply the elastomer directly to the heat exchanger or to adhesively bond the shaped elastomer.

[0027] The heat exchanger equipped with an elastomer can be installed in a motor vehicle and there assume the task of correspondingly exchanging heat between a cooling fluid in the motor vehicle and the ambient air. It can also be provided that a plurality of correspondingly protected heat exchangers are installed in a vehicle, for example when the heat exchanger is positioned in the wheel arch and thus on both sides of the motor vehicle. This is a commonly used installation situation in particular in electrically driven motor vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Other advantageous embodiments of the present invention are described by the following description of the drawings.

[0029] Figure 1 A heat exchanger tube is shown in cross section with an elastomer arranged at the tube end.

[0030] Figure 2 The heat exchanger according to the invention is shown in a front view,

[0031] Figure 3 A schematic diagram of a motor vehicle according to the invention is shown. DETAILED DESCRIPTION

[0032] Figure 1 A cross-sectional view transverse to the longitudinal axis of the heat exchanger tubes 2, 2', 2", 2'' of the heat exchanger 1 is shown. The heat exchanger tubes 2, 2', 2", 2''' are formed as flat tubes, characterized by two long tube wall sections and closed by two tube end sides 4, 4'. Here, the respective long tube wall sections are significantly longer than the first height h1 of the respective flat tubes. In the embodiment shown, the two tube end sides 4, 4' form arcuate sections. The flat tubes are bent from sheet metal and brazed or welded. It is therefore advantageous to have a soft transition at the bending point. It can also be proposed that the two tube end sides 4, 4' have one or more straight sections and transition to the long tube wall sections via arcuate sections.

[0033] During operation of the heat exchanger 1, the first tube end side 4 is oriented forward and thus points to the front side V of the vehicle in the motor vehicle 7. The second tube end side 4' therefore points to the rear side of the vehicle. This first tube end side 4 is therefore subject to an increased risk of being hit by rolled-up objects, such as stones or branches. This applies in particular during driving of the motor vehicle 7. These objects can hit the heat exchanger tubes 2, 2', 2'' in the area of ​​the first tube end side 4 and cause severe damage there, up to and including leakage on the heat exchanger tubes 2, 2', 2'', 2'''. This can lead to a breakdown of the motor vehicle 7 and to a loss of coolant or refrigerant to the environment.

[0034] Therefore, the elastomers 3, 3', 3'' are arranged on the first tube end sides 4 of the heat exchanger tubes 2, 2', 2', respectively oriented forward, and the elastomers protect the respective first tube end sides 4 from collision with flying objects. Here, the elastomers 3, 3', 3'' are arranged on the respective first tube end sides 4 so that the respective first tube end sides 4 are covered at the second height h2. The respective elastomers 3, 3', 3'' contact the respective first tube end sides 4 over the entire second height h2, and thus the respective elastomers 3, 3', 3'' can be particularly firmly placed on the respective first tube end sides 4. Here, the second height h2 is smaller than the first tube height h1, but corresponds to at least 80% of the first tube height h1.

[0035] The respective elastomer 3, 3', 3'' can either be preformed and subsequently applied to the respective first tube end side 4 in the desired length using a suitable adhesive, or can be applied in a particularly advantageous manner in liquid form to the respective first tube end side 4 in the desired length L1, L2 after assembly of the heat exchanger 1.

[0036] In this case, a suitable silicone material can advantageously be used, which can be applied in a simple manner and, after drying, firmly adheres to the respective first tube end 4 and forms the respective elastomer 3, 3', 3'' according to the invention. However, all other known elastic materials can also be used, which can be applied either preformed or in liquid form.

[0037] The respective elastic body 3 , 3 ′, 3 ″ has a third height h3 , which corresponds to at least three times the tube wall thickness d of the respective heat exchanger tube 2 , 2 ′, 2 ″.

[0038] Preferably, the respective elastomer 3, 3', 3" has a continuous course in its bulge and thus forms a kind of raised projection on the respective first tube end side 4. As a result, the particularly sensitive tip of the respective first tube end side 4 is accordingly protected with a particularly large amount of elastic material. However, the transition of the respective first tube end side 4 to the long tube wall section is protected with less elastic material, which is not a disadvantage, since the heat exchanger tube 2, 2', 2" has a better resistance in the transition due to more tube material with respect to the collision direction and therefore requires less elastic material for protection.

[0039] Figure 2A heat exchanger 1 is shown in a front view. The heat exchanger 1 is composed of a plurality of heat exchanger tubes 2, 2', 2", 2''' stacked on each other, and corrugated ribs 5 are arranged between these heat exchanger tubes. The ends of the heat exchanger tubes lead into collectors 6 arranged on each side. Through the first collector 6, the fluid to be cooled is guided through the heat exchanger tubes 2, 2', 2", 2''' to the other side into the second collector 6. During the flow, the fluid to be cooled releases heat to the ambient air through the heat exchanger tube wall. The corrugated ribs 5 arranged between the heat exchanger tubes 2, 2', 2", 2''' increase the surface available for heat exchange and are flowed through by the ambient air. Typically, the heat exchanger 1 is used to cool a coolant, but can also be used as a gas heat exchanger in which the refrigerant absorbs or releases heat.

[0040] The heat exchanger 1 shown has a first and a second heat exchanger tube 2, 2', each having an elastomer 3 arranged on a respective first tube end side 4, which has a first length L1. The required length of the elastomer 3, 3', 3'', respectively applied to the tube end side 4 depends on the risk of collision caused by flying objects (such as stones). It can therefore be proposed that a part of the heat exchanger tubes 2, 2', 2'', 2''' is already shielded by a fan 8 arranged in front of the heat exchanger 1 or other components in the motor vehicle 7, so that stone impact is impossible. Therefore, the elastomer 3, 3', 3'' only needs to be arranged on the respective first tube end side 4 where a collision is expected.

[0041] The heat exchanger 1 therefore also has a third heat exchanger tube 2 ″, in which an elastomer 3 ′, 3 ″ is arranged, respectively, with a length L2 different from L1. It can also be provided that a further application length is provided in each case in order to specifically protect only the endangered areas of the heat exchanger 1 . Therefore, there is also a fourth heat exchanger tube 2 ′″, which in each case has no elastomer 3 , 3 ′, 3 ″ at all.

[0042] Because multiple embodiments are possible, these embodiments cannot be shown exhaustively. Figure 2 The embodiments shown are examples of possible implementations.

[0043] Figure 3The schematic diagram shows how the heat exchanger 1 is arranged in the motor vehicle 7. The heat exchanger 1 is arranged in the front area of ​​the motor vehicle 7, which is particularly well flowed by the driving wind. In this case, the heat exchanger 1 can be positioned vertically upright or tilted in the motor vehicle 7. In particular, in electrically driven motor vehicles 7, the heat exchanger 1 is usually arranged tilted in order to provide space for a front storage box under the engine hood. Usually, the motor vehicle 7 also has a fan 8, which can guide ambient air through the heat exchanger 1 in addition to the driving wind, for example when driving slowly or when stationary. It can also be proposed that a further heat exchanger is arranged in front of or behind the heat exchanger 1. Through these vehicle-specific arrangement possibilities, different possibilities are created for how objects, such as stones, can reach the heat exchanger 1. Therefore, the possibility of applying the protection achieved by the elastomers 3, 3', 3'' only in the endangered area produces the additional advantage of saving material.

[0044] Reference numerals list

[0045] 1 Heat exchanger

[0046] 2, 2', 2'' heat exchanger tubes

[0047] 3, 3', 3'' Elastomer

[0048] 4 Pipe end side

[0049] 5 Corrugated ribs

[0050] 6 Collector

[0051] 7 Motor Vehicles

[0052] 8 Fan

[0053] V front

[0054] h1 Height of the end side

[0055] h2 Height of the covering part

[0056] h3 height of the elastic body

[0057] L1, L2 Length of elastic body

[0058] d Pipe wall thickness

Claims

1. A heat exchanger (1) for a motor vehicle (7), comprising a first heat exchanger tube and at least one second heat exchanger tube (2, 2'), wherein: The heat exchanger tubes (2, 2') each have a first tube end side (4), wherein the first tube end side (4) is oriented toward the front side (V) of the motor vehicle (7), wherein the respective first tube end side (4) each has a first height (h1), wherein an elastomer (3, 3', 3'') is arranged on the respective first tube end side (4) over a respective first length (L1) of the first heat exchanger tube and the at least one second heat exchanger tube (2, 2'), The invention is characterized in that the respective elastomer (3, 3', 3") has a second height (h2) and the respective elastomer (3, 3', 3") covers the respective first tube end side (4) at the respective second height (h2) and abuts against the respective first tube end side.

2. The heat exchanger (1) for a motor vehicle (7) according to claim 1, characterized in that At least one third heat exchanger tube (2") has a respective elastomer (3, 3', 3") on a respective first tube end side (4), wherein the respective elastomer (3, 3', 3") is arranged on a respective second length (L2) of the respective first tube end side (4) of the at least one third heat exchanger tube (2"), and the respective second length (L2) is different from the respective first length (L1).

3. The heat exchanger (1) for a motor vehicle (7) according to claim 1 or 2, characterized in that The respective elastic body (3, 3', 3'') is concavely shaped in a direction oriented toward the respective first tube end side (4), and is convexly shaped toward a side facing away from the respective first tube end side (4).

4. A heat exchanger (1) for a motor vehicle (7) according to any one of the preceding claims, characterized in that The respective second height (h2) corresponds to at least 80% of the respective first height (h1).

5. A heat exchanger (1) for a motor vehicle (7) according to any one of the preceding claims, characterized in that The third height (h3) of the respective elastomer (3, 3', 3") corresponds to at least three times the tube wall thickness (d) of the respective heat exchanger tube (2, 2', 2") .

6. The heat exchanger (1) for a motor vehicle (7) according to claim 5, characterized in that The respective elastomer body (3, 3', 3") has in its cross-sectional profile a continuous course starting from the respective first tube end side (4), which has a maximum rise at a third height (h3) of the respective elastomer body (3, 3', 3") .

7. A heat exchanger (1) for a motor vehicle (7) according to any one of the preceding claims, characterized in that At least one fourth heat exchanger tube (2''') has no elastomer (3, 3', 3'').

8. A heat exchanger (1) for a motor vehicle (7) according to any one of the preceding claims, characterized in that The respective elastic bodies ( 3 , 3 ′, 3 ″) are made of silicone material. 9 . A motor vehicle ( 7 ) comprising a heat exchanger ( 1 ) according to claim 1 .

Images