WO2022219081A1

WO2022219081A1 - Structural component and vehicle

Info

Publication number: WO2022219081A1
Application number: PCT/EP2022/059946
Authority: WO
Inventors: Hans-Peter Dahm; Holger Seidlitz; Felix Kuke
Original assignee: TGM Lightweight Solutions GmbH; BRANDENBURGISCHE TECHNISCHE UNIVERSITÄT COTTBUS-SENFTENBERG, Körperschaft des öffentlichen Rechts
Priority date: 2021-04-16
Filing date: 2022-04-13
Publication date: 2022-10-20
Also published as: DE102021109621A1; EP4323259A1

Abstract

The aim of the invention is to make it possible to increase the area provided for a drive unit, in particular a motor, while increasing or at least maintaining the cooling power in such a way that no visible adaptations of the outer vehicle geometry are required. This is achieved by a structural component (10) for a vehicle, having at least one structural element (1) which provides a shape, at least one closed coolant channel (2) for conducting a coolant fluid, and a coolant inlet and coolant outlet for connecting the coolant channel (3) to an external coolant circuit, wherein the structural element (1) and/or the coolant channel has at least regions that have a polymer through which carbon elements pass or consist of such a polymer.

Description

STRUCTURAL COMPONENT AND VEHICLE

The invention relates to a structural component and a vehicle, in particular a motor vehicle having one.

In addition to greater safety, the development of vehicles on land, on water and in the air is increasingly aimed at higher speeds. In motor vehicles in particular, ie vehicles driven by engines, this depends on the ratio of the power of the engine to the weight and resistance of the vehicle. A mere increase in engine power is often associated with an increase in the size and weight of the engine and with an increase in weight of other connected components, so that it usually cannot be converted into an increase in efficiency, or not to the full extent. For example, the cooling capacity must be increased along with the engine power.

Effective cooling of a combustion engine is a prerequisite for high performance. Thus, an increase in the cooling capacity is accompanied by a multiplication of the cooling elements and thus both with an increase in the weight of the vehicle and with an increased space requirement for the cooling elements in the engine compartment.

Despite their low thermal conductivity, the materials currently used for current heat transfer systems are mainly stainless steel, aluminum and unreinforced plastics in order to ensure the required resistance to corrosion and media. For highly stressed liquids, it is necessary to use more complex nickel-chromium-molybdenum alloys, which, in addition to the higher density, also have a lower thermal conductivity.

In order to reduce the weight, light metals, in particular aluminum as a low-weight material, have been increasingly used in the construction of cooling units and internal combustion engines in recent years. However, alkali metal borates, which are known to be good corrosion inhibitors for cast iron engines, do not protect aluminum well from corrosion (JP 49-5509), so this alternative introduces additional problems. The high material weight, the low thermal conductivity, the high costs and the susceptibility to corrosion represent a considerable disadvantage. Although the heat exchangers installed here have a comparatively high efficiency, this is significantly reduced when considering the energy balance due to the high dead weight and the size. In addition, not least because of the increased space requirement, the increase in engine power is severely limited and the means currently available have already come to an end, especially if the intention is to stick to well-known and classic geometries.

The object of the invention is now to provide a way of increasing the space available for a drive unit, in particular a motor, while increasing or at least maintaining the cooling capacity in such a way that no visible adjustments to the outer vehicle geometry are necessary.

This object is achieved by a structural component and a vehicle having the features of the independent claims.

Thus, a first aspect of the invention relates to a structural component for a vehicle, which has at least one shaping structural element, which has at least one closed coolant channel connected to the structural element in a form-fitting or material-locking manner for conducting a coolant fluid, as well as a coolant inlet and a coolant outlet for connecting the coolant channel to an external one Has coolant circuit. In other words, the structural component according to the invention is set up to enable heat exchange between a surface and the coolant that is or can be guided in the coolant channel. The structural component acts as a heat exchanger, or the heat exchanger is integrated into the structural component. Thus, when used as intended, the structural component assumes at least part of the cooling capacity in a vehicle. Depending on the further design of the structural component, the cooling capacity at least achieves that of a conventional heat exchanger.

Structural components are therefore characterized by a particularly large surface-to-volume ratio. In comparison to solid cast parts with a similar external shape, the weight is reduced many times over. This is achieved in that the shaping outer surface has a very small wall thickness and stabilizing elements extend from this at a defined point. In the present case, the structural element is to be understood as meaning the shaping outer surface. Furthermore, in the present case the coolant channel is designed as a stabilizing element of the structural component.

The coolant channel itself is therefore not to be arranged on an outer surface of the structural component. As a result, the arrangement of the coolant channel does not determine the external geometry of the structural component. Thus, no additional structures of the heat exchanger are preferably required. Rather, the heat exchanger is integrated into the structural element in such a way that it uses the existing structure. In other words, there is no additional heat exchanger in flea spaces, i.e. arranged adjacent to the structural element of a structural component, but is formed from structural element and stabilizing elements. This has the advantage that no further component and thus no additional weight or density has to be introduced.

According to the invention, the structural element and/or the coolant channel has an area which has or consists of a polymer interspersed with carbon elements. Such polymers are known, for example, from DE 102019 106387, DE 102018 102061 and DE 102017 108079 and are characterized by particularly high thermal conductivity. As a result, the structural element dissipates heat from the coolant channel via the wall thickness and its entire outer surface, and the cooling fluid is thus cooled.

This provides a heat transfer system with high thermal conductivity, high corrosion resistance and significantly reduced component weight, which means that additional connection and conventional heat transfer systems can be substituted. In addition, when the structural component according to the invention is arranged in the vicinity of the heat source, a significant shortening of the paths of the coolant system and consequently a significant reduction in the amount of coolant can be achieved.

Since the heat exchanger is integrated into existing components, omitting a conventional heat exchanger leads to a reduction in the number of parts and consequently to a reduction in the overall weight.

Ultimately, the performance of drive units has hitherto been limited by the possible cooling capacity, which is overcome with the structural component according to the invention.

The carbon elements, carbon particles, graphene and/or carbon fibers and/or nanotubes are particularly advantageous. These turned out to be particularly suitable for increasing the thermal conductivity and, depending on the design, also for strengthening the structural component. It was also shown that the heat conduction is further optimized if the carbon elements are specifically arranged in the material, that is, on the one hand, are in contact with one another and/or are aligned with one another and with the surface of the structural element. It is particularly preferred if the direction of extension of the fibers or tubes or of the particles which are in contact with one another are arranged at an angle in the range from 10 to 90°, in particular in the range from 30 to 90°. This increases the rapid dissipation of heat.

Basically, structural components are large, thin-walled parts. This means that the amounts of material are relatively small compared to the part surface. However, the structural components also have thick-walled sections with accumulations of material. In relation to the mold surface, this creates areas that are thermally undercooled on the one hand and places that are thermally overloaded on the other. An alignment in the range from 10 to 60°, in particular from 30 to 50°, is also provided in particular in areas where accumulations of material are formed. Such accumulations of material are preferably provided on sections of the structural element which extend perpendicularly from an adjacent surface, ie a profile structure and/or a tapering of the surface results. With conventional materials, there is a risk of thermal bridges in these sections, which is reduced by the preferred orientation of the carbon elements of the structural component according to the invention, in particular in the preferred embodiment.

In a preferred embodiment of the invention, it is provided that the structural element has one, preferably a plurality of through openings.

It is further preferably provided that adjacent walls of the passage openings have a distance in the range of 0.5 to 10 cm, preferably 1 to 5 cm. The distance is proportional to the laminarity of a fluid flowing through the channel.

The passage openings preferably have a honeycomb, round, elliptical, meandering or other regular cross section. Such through-openings can, for example, be designed to carry fluid and therefore, when used as intended, a coolant or air can flow through them.

In a preferred embodiment of the invention, the structural component, in particular the shaping surface and/or a stabilizing element, forms an open or closed air duct for directed air flow, at least in regions. In this configuration, in particular the area of the structural element forming the air duct or adjoining it has the carbon elements. In this configuration, removal of the heat dissipated by the structural element from the cooling channel of the structural component is increased due to the air guided and accelerated in the air channel. Consequently, the efficiency of the cooling effect of the structural component acting as a heat exchanger is increased.

Thus, compared to conventional heat exchangers, the heat-exchanging unit has a larger volume flow with a partially increased flow rate. The resulting air flow enables an additional coolant reduction.

Depending on the design, the structure enables turbulent flows on the walls of the through openings and their end sections, which largely leads to an increase in the molecular contacts on the surface and thus to higher heat transfer. Depending on the design of the air duct, the air flowing out of the air duct is guided in such a way that lift and downforce effects can be achieved in a targeted manner, which, for example, increase the performance of sports cars or positively influence the flight characteristics of an aircraft.

In the present case, an air duct is to be understood as an element that directs and limits an air flow, which has an air inlet through which the air flows into the air duct and an air outlet arranged downstream, as well as a plurality of walls which limit the sides of the duct. Depending on the configuration and in particular the diameter and configuration of the walls, the air flow guided in the duct is laminar and/or turbulent.

A closed air duct of a vehicle is, for example, delimited on all sides by one or more components and leads, for example, outside air to a cooler arranged inside, for example in the engine compartment or in the area of a side sill. Open air ducts, on the other hand, are open on at least one side of the duct, ie have no wall there. Such open air ducts are arranged, for example, at the rear of a vehicle or on the top or bottom of wings.

Particularly advantageously, branches of the structural elements in the form of lamellae, honeycombs, fins or rods extend into or through the air duct in relation to its cross section. This leads to an advantageous increase in surface area and consequently to a further increase in the efficiency of the heat exchanger function of the structural component. In addition, the arrangement of the further structural elements leads to a significant increase in stability, particularly when the branches extend through the air duct, ie connect two opposing walls of the air duct. This is particularly advantageous for the configuration of the structural component according to the invention as an active or crash-loaded structural component.

If the branches are designed in such a way that they extend not only over the cross section but over the entire length of the air duct, they form a plurality of open or closed sub-ducts in the air duct and thereby increase the heat-exchanging surface of the structural element and, if necessary, the flow rate. If, on the other hand, they are only arranged in one section relative to the length of the air duct, they act as disruptors and primarily influence the type of air flow.

In a preferred embodiment of the invention, it is provided that the wall in the area of the passage openings has a wall thickness in the range from 0.5 to 30 mm, preferably in the range from 1 to 10 mm. In this area, the ratio of stability to heat conduction is optimized. The structural component is advantageously designed for air discharge, air forwarding and/or air ducting, in particular as an air baffle, spoiler, floor baffle, monocoque, crash element, side member, side skirts, air intake unit, in particular radiator grille or as part of one of the aforementioned and/or part of a body, a car body structure , a chassis structure, an aircraft fuselage, an aircraft wing or a rocket stage. It was found that in these configurations the structural component can take over the function of a conventional cooler and can even surpass the cooling capacity that can be provided by such a cooler. As a result, the engine output can be further increased with the same engine compartment size and reduced weight.

A further aspect of the invention relates to a vehicle having a cooling circuit, an air flow duct and a structural component according to the invention, the coolant duct being connected to the cooling circuit in a fluid-conducting manner or being part of the cooling circuit.

In a particular embodiment of the invention, it is provided that a cooler having cooling ribs through which fluid flows is replaced by the structural component. Thus, the weight of the vehicle as well as the engine compartment occupied by the heat exchanger is significantly reduced with at least the same cooling capacity and the power can therefore be increased by a drive unit, in particular by an internal combustion engine, with the external vehicle geometry remaining the same.

Unless otherwise stated in the individual case, the configurations described can advantageously be combined with one another.

The invention is further described below using the example of figures.

Show it:

Figure 1: a perspective cross-sectional drawing of a detail of a structural component according to the invention in the area of an air duct in a first embodiment of the invention,

FIG. 2: a sectional drawing of a section of a structural component according to the invention in the area of an air duct in a second embodiment of the invention, and

FIG. 3: a schematic detailed drawing of a section of the device according to the invention

Structural component in the second embodiment.

FIG. 1 shows a cross-sectional drawing of a detail of a structural component 10 according to the invention in a perspective view. The structural component 10 has a structural element 1, which is in branched in the embodiment shown in such a way that a plurality of honeycomb-shaped channels 5a is formed, of which a closed honeycomb is shown in the detail shown.

The channels 5a preferably have a diameter in the range from 0.2 mm to 200 mm. The larger the diameter of the channels 5a, the larger the volume flow flowing in them and the larger the proportion of laminar flow.

In the embodiment shown, the branches 1a of the structural element 1 extend to the left, so that the branches 1a form a closed channel 5a. When used as intended, for example when the structural component 10 is arranged in the air duct of a motor vehicle, the closed duct 5a can serve to guide an air flow L.

Furthermore, the structural component 10 has a coolant channel 3 . The coolant channel 3 is designed as a closed channel for conducting a fluid, for example a liquid or gaseous coolant. In the embodiment shown, the coolant channel 3 runs transversely to the flow direction of the air flow L, so that a flow direction of a fluid flow F runs transversely to the flow direction of the air flow.

Furthermore, the structural component has a coolant inlet and a coolant outlet (both not shown), both of which are connected to the coolant channel 3 in a fluid-conducting manner.

The structural component 10 has in particular a fiber-reinforced plastic (CFRP) 3 and is manufactured, in particular in the section shown. In comparison to known materials used as a structural component, the structural component 10 also has carbon elements 3a. These carbon elements 3a as particles, or preferably in the form of short fibers, with a length of up to 1 mm and a thickness in the range of 5-6 pm, long and / or continuous fibers with a length of 1 mm and a thickness also in range of 5-6 pm, carbon nanotubes with a diameter from 0.4 nm, or carbon particles with particle sizes in the range of 10-70 pm. Also conceivable is the use of metal powder, which preferably has a particle diameter of more than 15 μm or, in the case of a diameter of less than 15 μm, has been processed into filaments by means of compounding.

The carbon elements 3a are preferably aligned in polymer 3 essentially transversely to the material thickness of the polymer 3 .

FIG. 2 shows a structural component 10 according to the invention in a further preferred embodiment. Shown is the cross section of an air duct 5, which is provided, for example, in a motor vehicle for guiding outside air into the engine compartment. The structural component 10 has a structural element 1 delimiting the air duct 5 on three sides. On a surface of the structural element 1 facing the interior of the air duct 5, fin-shaped branches 1a of the structural element 1 extend into the air duct 5 and form open ducts 5b.

In the embodiment shown, the fins pierce the structural element so that they also emerge from the structural element 1 on a surface of the structural element 1 that is remote from the air duct 5 .

In the embodiment shown, the fin-shaped branches 1a are reinforced in the area of the puncture point to stabilize the fins, ie they have an accumulation 4 of material.

Furthermore, the structural component 10 has a coolant duct 2 which adjoins the structural element 1 and is connected to the cooling duct 2 in a form-fitting and/or material-locking manner in the embodiment shown.

FIG. 3 shows a detailed drawing of the embodiment of the structural component 10 according to the invention shown in FIG. 2. This shows in particular the orientation of the carbon elements 3a. Thus, the carbon elements 3a preferably extend in the direction of extension in the area of the fins, while in the area of the structural element and a wall of the coolant channel 2 they are aligned essentially transversely to the direction of extension of the structural element 1 or of the coolant channel 2, in particular at an angle in the range of 10 -50° to these. In the area of the material accumulations 4, the carbon elements 3a are preferably aligned at an angle of 40-50°, in particular at an angle of 45° to the direction of extension of the gate element 3 and to the direction of extension of the respective branch 3a or the respective fin 3a.

The structural component 10 described has the function of ensuring the most efficient possible heat transfer from a fluid flow F to an air flow L. For this purpose, the lightest possible materials are used, in particular fiber-reinforced polymers 3, whose conductivity is increased by thermally conductive carbon elements 3a. The thermal conductivity is further increased by the orientation of the carbon elements 3a, since the thermal conductivity of the carbon elements 3a is increased in the direction in which the carbon elements 3 extend, the thermal conductivity of the structural element 1 and thus the efficiency of the entire structural component also increases if the carbon elements 3A are arranged essentially transversely to the Extension direction of the structural element 1 run. reference list

L airflow

F fluid flow

10 structural component

1 Structural element la branches of the structural element, honeycomb/fin-shaped

2 coolant channel

3 Polymer/fiber reinforced plastic

3a carbon elements (carbon fibers, carbon nanotubes, plastic particles)

4 material accumulation

5 air duct

5a closed channel

5b open channel

Claims

patent claims

1. Structural component for a vehicle, having at least one shaping structural element, at least one closed coolant duct for conducting a coolant fluid and a coolant inlet and a coolant outlet for connecting the coolant duct to an external coolant circuit, the structural element and/or the coolant duct having at least areas which polymer interspersed with carbon elements or consists of such.

2. Structural component according to claim 1, wherein the carbon elements are carbon particles, graphene and/or in particular aligned carbon fibers and/or carbon nanotubes.

3. Structural component according to claim 2, wherein the carbon fibers or carbon nanotubes in the structural elements are aligned in the direction of extent of the wall, perpendicular to the direction of extent or at an angle in the range of 1 to 90°, preferably in the range of 1 to 60° to the direction of extent of the wall are.

4. Structural component according to one of the preceding claims, further comprising at least one, preferably a plurality of through-openings, wherein adjacent walls of the through-openings have a distance in the range of 0.5 to 10 cm, preferably 1 to 5 cm.

5. Structural component according to one of the preceding claims, wherein the wall has a thickness in the range of 0.2 mm to 200 mm in the region of the through-openings.

6. Structural component according to one of claims 1 to 3, wherein the structural component at least partially forms an open or closed air duct for directed air flow and has the carbon elements in the region of the air duct.

7. Structural component according to claim 6, wherein structural elements, in particular honeycomb, fin or rod-shaped, extend into the air duct or through the air duct.

8. Structural component according to one of the preceding claims, wherein the structural component is designed for air discharge, air forwarding and/or air passage, in particular an air deflector, a spoiler, a floor deflector, a monocoque, a crash element, a side member, a side skirt, an air intake unit, in particular a radiator grille or is a part of any of the foregoing and/or a part of a body, body structure, landing gear structure, fuselage, wing or rocket stage.

9. Vehicle having a cooling circuit, an air flow channel and a structural component according to one of the preceding claims, wherein the coolant channel is connected to the cooling circuit in a fluid-conducting manner or is part of the cooling circuit.

10. Vehicle according to claim 9, wherein a radiator having cooling fins through which fluid flows is replaced by the structural component.