DE10209237A1 - Air-cooled front cooler module - Google Patents

Abstract

An air-cooled front cooler module for a motor vehicle with an internal combustion engine has one or more cooler networks. These cooler networks have pipes and serve as heat exchangers. A cooling medium flows through each of them and cooling air flows outside. Furthermore, one or more fans with fan drives are provided. DOLLAR A The fan drive of the fan (s) protrudes into at least one of the cooler networks. DOLLAR A In a preferred embodiment, the fan drive is located in an area that is in the slipstream of a bumper. DOLLAR A The pipes of the radiator network are left out in this area.

Description

The invention relates to an air-cooled front cooler module for a motor vehicle with an internal combustion engine, one or more heat exchangers with radiator grids with pipes that use one or more cooling media flowed through and cooled by cooling air, and with one or several fans with fan drive.

Motor vehicles usually have internal combustion engines, too need to be cooled. It's about cooling the coolant itself, but also about the charge air. Increasingly, motor vehicles also have to Air conditioning capacitors are equipped. This cooling is expediently built in Form of front cooler modules that are located directly behind the front of the Vehicle are arranged where they are exposed to the driving wind. you tried to make the cooler as compact and with small external dimensions build up because of the space in the engine compartment immediately behind is becoming increasingly scarce, as more and more and larger units are also there increasing technology and increasing demands have to.

The front end of the motor vehicle is said to have a certain desired stability to protect the occupants in the event of a collision. At the same time Front part of the motor vehicle but also remain compliant to do that The risk of injury to pedestrians is as low as possible in the event of an impact hold. Attempts are being made to resolve this contradiction through compromise solutions to encounter. Since the front cooler modules do not affect the stability of the front of the Motor vehicle contribute, but the flexibility of the crumple zone influence them unfavorably, try them from the remove the immediate deformation area.

In addition, one would like to reduce the openings in the front of the motor vehicles as much as possible for aerodynamic and acoustic reasons. If these openings (colloquially often referred to as "radiator grille") are relatively large, the air resistance (c _w value) also increases and the noise level caused by the motor vehicle also increases. Both effects are undesirable, so you tend to want to reduce these openings.

Both trends, on the one hand the increasing compacting of the cooler and on the other hand, the adjustment of the access routes for the driving wind complicate the Construction of coolers. It should be borne in mind that larger engines also have one need appropriate cooling.

The object of the invention is therefore an air-cooled front cooler module for To propose motor vehicles that can meet these requirements.

This task is achieved in a generic front cooler module solved that the fan drive of the fan in at least one of the cooler networks protrudes.

Conventional is most common in compacting attempts in the prior art attempts have been made to approach the exterior dimensions of a radiator focus, so somehow reduce its dimensions without losing its Function at risk.

According to the invention, however, the opposite is done: it becomes practical the central, central area of a cooler network, at least that one The cooler network that is closest to the fan wheel is simply left out. It arises practically a "cooler with a central hole". The external dimensions (width, Length, height) remain essentially unchanged.

So the fan drive, which was previously in the undesired form in the Engine compartment had to stretch in, practically in this vacant area be placed inside the front cooler module so that the Fan drive can now be run strong and inexpensive, reducing the cooling performance further improved.

The fan wheel itself can now also be placed very close to the cooler network. On the other hand, the fan guard, which was previously required, can now be completely replaced to be dispensed with, what the hitherto occurring obstruction of the outflow at Avoids airflow, and further improve the Cooling performance leads.

The approach surprisingly leads to success: Although parts of the Cooler network simply disappear or no longer in comparison to the prior art are structured as evenly as before, there are clear advantages for the Overall depth of the complete front cooler module. Several inches of space in The direction of the vehicle's longitudinal axis is obtained. There are little losses to the capacity of the heat exchanger, which is particularly important in The following embodiments to be discussed are negligible, compared to the achievable advantages.

Other units can also be placed in the resulting recesses be integrated, the previously unfavorably shaped within the engine compartment had to be ordered.

The cooler is preferably put out of function exactly where it is anyway has its lowest efficiency, namely in that section of the Radiator, which is completely covered by the bumper and therefore lack of driving wind only contributes to the cooling effect through free convection. This is done by the There is a recess for the fan drive in the slipstream of a shock absorber. In particular, however, the space released is preferred To use embodiments of the invention particularly useful.

Even if there are other vehicle elements in the way of a motor vehicle the cooling air to the front cooler module are preferably the Cut out the pipes exactly behind the vehicle elements.

To the vehicle elements in the path of the cooling air, which the homogeneous flow of the front cooler module, so to speak to the stems The most important thing in front of the radiator is the bumper, but not exclusively.

It turns out that the now more homogeneous cooling the less favorable Mixing effects of otherwise differently cooled cooling medium in the collectors drastically reduced and thus improved efficiency, especially since a better one Heat flow despite the shorter residence time of the cooling medium External surfaces can be observed.

There are several options, such as a recess for the fan drive can be realized within the cooler. It is preferred if one as usual, the cooler network has some side by side horizontal pipes can be omitted.

Alternatively, it is also possible to place the pipes in certain middle areas huddle, i.e. evenly or suitably from the edge to the center in Steps or curves to rise and / or to let down, so that in the resulting increased distances between the pipes Forms recess.

Technically, another possibility is that one of the Cooler networks are made up of two subnetworks which are arranged one above the other and have a distance from each other. Between these two parts of the Cooler network is then again the recess for the fan drive. The two parts of the radiator network can be practically independent and each form their own radiator network. The connections of these two Parts of the cooler network should be coordinated appropriately so that they together the functionality of this overall cooler network can ensure.

These two subnets do not necessarily have to be the same size. By subnets of different sizes can also be used in a not exactly central, but still in Cutout located in the central area of the cooler network.

The invention is applicable to both front cooler modules that multi-layer structure of multiple cooler networks are designed as well Front cooler modules, in which the individual cooler networks are combined, so-called monoblocks.

The cooler modules with their cooler networks are preferably layered arranged perpendicular to the cooling air. This means that the cooling after the Cross flow principle takes place, that is, the cooling air perpendicular to the cooling medium in flows into the radiator grids. In a first approximation, the direction of flow is Cooling air parallel to the driving wind, but it is also depending on the specific structure the motor vehicle or the front end angle of about 20 ° possible depending on the direction of movement.

It is also preferred if the flow resistance of the Front cooler module for the cooling air over the area swept by the fan wheel through the Use of an air-permeable screen remains approximately constant.

Further preferred features can be found in the subclaims.

An exemplary embodiment of FIG Invention described in more detail. Show it:

Figure 1 is a schematic vertical section through the front of a motor vehicle with a front cooler module according to the invention. and

FIG. 2 shows a schematic view in the direction of travel of the embodiment of the front cooler module from FIG. 1.

The front part of a motor vehicle shown in FIG. 1 is shown purely schematically in section. The vehicle has a body 10 , of which only the bonnet 12 can be seen in the sectional view. To the right outside the picture, the engine compartment (not shown) and behind it the passenger compartment would follow. At the bottom of FIG. 1, the vehicle floor 11 and the wheels would be conceivable. The fenders of the body are in front of or behind the image plane and are therefore also missing in the sectional view.

The vehicle would move to the left. A bumper 13 and a stiffening 14 for the bumper 13 are therefore indicated schematically there. A spoiler 15 extends obliquely from the vehicle floor 11 up to the bumper 13 . The spoiler 15 has large openings in which a ventilation grille 16 is arranged. The ventilation grille 16 in turn has openings. There are also ventilation grilles 16 between the bumper 13 and the bonnet 12 . Cooling air L _{A can} flow in from the left through the ventilation grille 16 . This is indicated by six arrows, cooling air L _A flowing in both above and below the bumper 13 .

The bumper 13 and its stiffening 14 are thus vehicle elements in the path of the cooling air L _A.

This cooling air L _A now flows onto a front cooler module 20 . In the illustrated embodiment, the front cooler module 20 consists of several elements. A different structure is also conceivable here, depending on the vehicle type.

Not every vehicle has all of these elements, but others can added.

In the illustrated embodiment, the front cooler module 20 has an air conditioning condenser 21 , a charge air cooler 22 , a coolant cooler 23 and finally a fan 30 . The structure is layered, with each layer arranged perpendicular to the direction of travel. The first layer in the direction of travel is the air conditioning condenser 21 , followed by the charge air cooler 22 , the coolant cooler 23 and the fan 30 . The cooling air L _A therefore flows perpendicular to these layers.

The fan 30 has a fan drive 31 and a fan wheel 32 . There are also embodiments in which the fan 30 is arranged in the direction of travel in front of the heat exchangers, that is to say to the left of these in the figure.

Each individual layer, for example the air conditioning condenser 21 , is constructed as a separate heat exchanger. In this example, three independent cooler networks 24 are created , one for each heat exchanger.

For the charge air cooler 22 , this is again indicated separately in an enlarged area at the bottom left in FIG. 1. The cooler network 24 of the heat exchanger is a system of fins and pipes 25 through which a cooling medium L _M flows. This cooling medium L _M essentially flows from left to right or from right to left, ie horizontally, just as the cooling air L _A flows horizontally. So both meet on the cross flow principle for cooling. The medium L _{M to} be cooled can be air, cooling water or another refrigerant, for example carbon dioxide CO ₂ . It flows through oval tubes or round tubes 25 , which are preferably at a constant distance from one another. On the right and left of the vehicle, inflow collectors or outflow collectors 26 are provided, which will be described in more detail in connection with FIG. 2.

The heat transport between the cooling air L _A and the cooling media L _M mainly takes place on the way of free and forced convection, the heat radiation, on the other hand, has only a small proportion.

Behind the sandwich arrangement of the various heat exchangers 21 , 22 , 23 with their cooler networks 24 there is also the fan 30 in parallel and to a certain extent in layers. For a front radiator module, a corresponding room depth must be kept in the vehicle, because the actual engine compartment can only be built up to the right of the radiator. The front cooler module 20 must be able to work both in the driving wind mode and in the pure fan mode. A view of FIG. 1 shows that the end face of the entire radiator network 24 is generally approximately twice as large as the openings of the ventilation grilles 16 between the spoiler 15 , the bumper 13 and the bonnet 12 . In both driving wind mode and fan mode, only partial areas of the heat exchanger are directly flowed through, i.e. cooled by forced convection. The rest of the surface gives off the heat by means of free convection. As a result, different temperatures of the respective cooling medium L _M are normally formed in each of the many parallel tubes 25 through which flow 25 flows. The media from the better and poorly cooled areas mix in the outflow collector to form an average temperature there.

In contrast to the prior art, it is precisely the area behind the bumper 13 that is kept free from the tubes 25 of the heat exchangers 21 , 22 and 23 of the front cooler module 20 . The entire part of the cooler network 24 which is actually occupied by pipes 25 is subjected to direct convection from cooling air L _A by forced convection. The conventionally poorer cooled areas are eliminated. As can also be seen in FIG. 1, this measure is not necessarily carried out in all cooler networks 24 , but in particular in the cooler networks 24 which are furthest back in the direction of travel, in the example shown the charge air cooler 22 and the coolant cooler 23 .

These are the heat exchangers closest to fan 30 .

Of course, the cooling effect in this area is dispensed with in these two cooler networks 24 , the cooling actually taking place in the outer areas, on the other hand, is more effective and the unfavorable effects resulting from the mixing are avoided. The entire volume flow of the charge air and the coolant of the charge air cooler 22 and of the coolant cooler 23 is each shifted into the area of the forced convection. The dwell time, for example, of an air particle in the pipe 25 of the charge air cooler 22 becomes shorter because the speed of the air particles increases due to the reduced flow cross section. However, the temperature difference ΔT in the wall layer area of the cooler network 24 of the charge air cooler 22 is greater, since the cooling air L _{A also flows} directly. In total, this results in a better heat flow Q and thus in a better cooling despite the smaller radiator network area, although a considerable part of the pipes and fins of the radiator network 24 has been omitted.

A look at FIG. 2 shows that the solution is also independent of whether there are heat exchangers in which the coolant medium L _{M flows} only once from one collector 26 to the other collector 26 or whether the cooler network 24 is flowed through several times. The flow in the first type is also referred to as "I flow", that in the second type as "U flow" or "S flow".

Fig. 2 is "I" -durchströmte heat exchanger with collectors 26 for the inflow of hot, uncooled medium and for the outflow of cooled in the heat exchanger cooling medium L _M. The arrangement of the inlet and outlet connections over the diagonal is optimal, which ensures a uniform volume flow over all pipes 25 within each of the three heat exchangers 21 , 22 , 23 . This also contributes to lower pressure drops and better temperature distribution.

A renewed look at FIG. 1 again shows that not only no disadvantages arise from omitting the central tubes 25 in at least some of the cooler networks 24 of the heat exchangers. The middle area behind the bumper 13 , which has hitherto been poorly flowed, also offers about 5 dm ³ volume, which were previously occupied by pipes 25 . This space is now vacant and can be used differently.

For this purpose, it is advisable, as also shown in FIG. 1, to accommodate the drive unit 31 of the fan 30 here. This protrudes conventionally into the engine compartment and has to be accommodated as space-saving as possible due to the unfavorable and actually not desired, also flat design.

In an arrangement according to this embodiment of the invention, however, the length of the drive unit 31 is only relevant for the depth of the front cooler module 20 from a certain limit. This means that inexpensive and powerful fans can be used.

Due to the free space inside the heat exchanger, the fan 30 with its fan drive 31 can simultaneously be further optimized and thus possibly improve the overall effect of the cooler.

The fan wheel 32 is placed very close to the cooler network 24 of the coolant cooler 23 . In the illustrated embodiment of the invention, the outer race of the fan wheel 32 is at a distance of approximately 3 mm from the cooler network 24 of the coolant cooler 23 . As a result, it is now also possible to do without a conventional fan guard, which is therefore also not shown. Apart from the reduced effort, this also has the advantage that the outflow is not unnecessarily prevented by this fan cowl when driving wind mode.

In order to further optimize the invention, a seal 27 is used to achieve a better flow through the individual heat exchangers. This seal 27 closes the gap that forms between two heat exchangers, that is, two cooler networks 24 . This prevents suction of secondary air or bypassing certain parts of the front cooler module 20 by the cooling air L _A.

Since the fan 30 has the highest power density in the outer area of the fan wheel 32 , that is to say the maximum negative pressure, the wing of the fan wheel 32 , which flats outward and flatter, is arranged in such a way that the distance between the wing and the cooler network 24 increases from the inside to the outside. This can be seen particularly well in the sectional view in FIG. 1.

This also enables a better pressure distribution between the cooler network and the fan wheel 32 .

A fan 30 which is positioned relatively close to the inhomogeneous cooler network 24 could possibly tend to cause pressure pulsations in the transition region between the cooler network 24 and the air, which are then perceived as noise. In a preferred embodiment of the invention, this noise development is prevented by an air-permeable screen 40 . The air resistance of the panel 40 and the cooler module are approximately the same. The diaphragm 40 closes with its dimensions flush with the right edge of the front cooler module 20 in FIG . The aperture 40 thus also has a recording function for the fan 30 .

The aperture 40 also avoids the warm air being drawn in from the engine compartment by the fan 30 . The entire recessed area of the cooler networks 24 is therefore closed with the aperture 40 . The aperture 40 is airtight outside the area swept by the fan wheel 32 .

The front cooler module 20 according to the invention is suitable for personal vehicles as well as for trucks and other commercial vehicles. The idea can be extended not only to symmetrical arrangements as in FIG. 1, but also to more asymmetrical arrangements of bumpers 13 . Legend: 10 body
11 vehicle floor
12 bonnet
13 bumpers
14 stiffening of the bumper
15 spoilers
16 ventilation grilles
20 front cooler module
21 air conditioning condenser
22 intercooler
23 coolant cooler
24 cooler network
25 tubes
26 collectors
27 seals
30 fans
31 fan drive
32 fan wheel
40 aperture
L _A cooling air
L _M cooling medium

Claims (12)

1. Air-cooled front cooler module ( 20 ) for a motor vehicle with an internal combustion engine,
with one or more heat exchangers ( 21 , 22 , 23 ) with cooler networks ( 24 ) with pipes ( 25 ) through which one or more cooling media (L _M ) flow and outside of which cooling air (L _A ) flows, and
with one or more fans ( 30 ) with fan drive ( 31 ),
characterized by
that the fan drive ( 31 ) of the fan ( 30 ) projects into at least one of the cooler networks ( 24 ). 2. Air-cooled front cooler module according to claim 1, characterized in that the tubes ( 25 ) of this cooler network ( 24 ) omit the area for the fan drive ( 31 ). 3. Air-cooled front cooler module according to claim 1 or 2, characterized in that the recess for the fan drive ( 31 ) is in the slipstream of a bumper ( 13 ). 4. Air-cooled front cooler module according to one of the preceding claims, characterized in that the cooler networks ( 24 ) are arranged in a layer shape perpendicular to the cooling air (L _A ). 5. Air-cooled front cooler module according to one of the preceding claims, characterized in that the tubes ( 25 ) are omitted in the central region. 6. Air-cooled front cooler module according to claim 1 to 4, characterized in that the cooler network ( 24 ) with the recess has two sub-networks, which are arranged above and below the fan drive ( 31 ). 7. Air-cooled front cooler module according to one of claims 1 to 4, characterized in that the tubes ( 25 ) diverge adjacent to the recess from the edges to the center to form the recess. 8. Air-cooled front cooler module according to one of the preceding claims, characterized in that at least the tubes ( 25 ) of that cooler network ( 24 ) are omitted which is closest to a fan wheel ( 32 ) of the fan ( 30 ). 9. Air-cooled front cooler module according to one of the preceding claims, characterized in that seals ( 27 ) are provided which close the gap between the cooler networks ( 24 ) of the heat exchanger. 10. Air-cooled front cooler module according to one of the preceding claims, characterized in that the recessed area of the cooler network ( 24 ) is closed with an aperture ( 40 ). 11. Air-cooled front cooler module according to claim 10, characterized in that the cover ( 40 ) is at least partially permeable to air. 12. Air-cooled front cooler module according to claim 11, characterized in that the flow resistance of the front cooler module for the cooling air (L _A ) over the area swept by the fan wheel ( 32 ) remains approximately constant through the use of the air-permeable screen ( 40 ).