GB2479044A

GB2479044A - Cooling device for a motor vehicle

Info

Publication number: GB2479044A
Application number: GB1104434A
Authority: GB
Inventors: Udo Mildner
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2010-03-24
Filing date: 2011-03-16
Publication date: 2011-09-28
Anticipated expiration: 2031-03-16
Also published as: CN102198792A; DE102010012485A1; GB201104434D0; GB2479044B; US20110232865A1

Abstract

The present invention relates to a cooling device for a motor vehicle with a first heat exchanger 30 and with a second heat exchanger 16, which is arranged in vehicle longitudinal direction offset from the first heat exchanger 16. In the intermediate space between first and second heat exchanger a flow regulating device with a cross-sectional area through which cooling air can flow is arranged, whose permeability to cooling air is variable. Preferably the flow regulating device comprises a frame through which cooling air can flow and on which at least one actuator 36 changing the through flow of the regulating device is arranged. Preferably the actuator is designed as a roller blind 36. Also claimed is a motor vehicle with a cooling device as described.

Description

Cooling device for a motor vehicle

Description

Technical area The present invention relates to a cooling device for a motor vehicle with at least one first and one second heat exchanger each subjectable to cooling air.

Background

Cooling devices or cooling systems are indispensible for the discharge of the waste heat generated during the operation of a motor vehicle.

Popular cooling devices have a multiplicity of different heat exchangers which are subjected to cooling air onflow or throughflow and in this way can discharge thermal energy of a heat exchanger medium circulating in a circuit to the environment.

In addition to a radiator thermally coupled to a combustion engine known cooling systems comprise further heat exchangers such as for example a charge air cooler, a transmission oil cooler as well as a condenser of a vehicle air conditioner. All these heat exchangers are mostly arranged on a common cooling module, which furthermore comprises a fan arrangement for generating an air stream in order to generate a cooling air flow that is adequate for discharging the heat even in the low speed range or with the vehicle stationary.

Particularly when driving in a middle or higher speed range the headwind generates a dynamic air pressure that is adequate for the cooling of the heat exchangers.

Besides, if the vehicle for example is moved with uniform speed on a substantially level route the power demand on the drive unit is relatively low; accordingly, the heat quantity to be discharged to the environment is comparatively low.

However, especially in the higher speed range the aerodynamic of the motor vehicle plays an increasingly greater role. The supplied cooling air typically branched off from the headwind for example swirls in the region of the heat exchangers and of the vehicle floor. Permanently subjecting heat exchangers of a cooling device of a motor vehicle to cooling air can have a disadvantageous effect on the aerodynamics of the vehicle.

From DE 102 35 192 Al a cooling system is known, which in a first operating phase is cooled via a first air flow path and in a second operating phase by means of a second air stream passing a second air flow path. Here, a device for controlling the air stream flowing through the radiator is provided, wherein that device is arranged in the outflow region of the radiator. In this way, a more homogenous throughflow of the radiator over the entire cooling surface is to be realized so that the cooling capacity of the radiator and possible additional heat exchangers can be increased. That known device for controlling the air stream in this case is designed as covering device with at least one pivotable flap or with a lateral roller blind box. The covering device in this case however is arranged downstream of all heat exchangers seen in driving direction of the vehicle, as a result of which the installation space requirement of the cooling system in the vehicle is increased.

In contrast with this the objective of the present invention is to provide a cooling device that is optimized with respect to installation space requirement, which with respect to its cooling capacity is adaptable to different requirements and which in addition contributes to the improvement of the aerodynamics of the motor vehicle.

Invention The object on which the invention is based is solved by means of a cooling device according to Patent Claim 1 and with a motor vehicle according to Patent Claim 14. Individual advantageous configurations of the invention are the subject of dependent patent claims.

The cooling device according to the invention is designed for a motor vehicle. It comprises at least one first and one second heat exchanger, wherein the two heat exchangers are arranged offset from each other in vehicle longitudinal direction or in driving direction of the vehicle. The cooling device in this case is preferably designed as preassembled cooling module which comprises a multiplicity or even all heat exchangers of a motor vehicle cooling system and as an integrated unit can be preferentially arranged in the vehicle front region.

To improve the vehicle aerodynamics a flow regulating device is arranged in the intermediate space between first and second heat exchanger which comprises a cross-sectional area through which cooling air can flow.

The permeability of that cross-sectional area to cooling air can be changed. As far as this is concerned the flow regulating device comprises regulating or adjusting means for changing the throughflow-capable cross-sectional area of the flow regulating device.

Alternatively or additionally it can be further provided that instead of changing the cross-sectional area through which a flow can freely flow to merely change the flow resistance for supplied cooling air. With the help of the flow regulating device arranged in the intermediate space between at least two heat exchangers the quantity and the flow rate of cooling air to be supplied can be variably and preferentially continuously changed in accordance with the cooling requirements of the cooling device.

If for instance dependent on the present driving performance only a comparatively low cooling capacity is to be generated by the cooling device the cooling air permeability of the flow regulating device can be lowered to improve the vehicle aerodynamics. Upon provision of an increased cooling capacity by contrast the permeability of the flow regulating device to cooling air is to be maximized for example through enlarging the throughflow-capable cross-sectional area.

Here it proves to be particularly advantageous that the flow regulating device seen in vehicle longitudinal direction is arranged in an intermediate space formed by two heat exchangers. Here, installation space that is available between the respective heat exchangers anyhow is utilized so that for the flow regulating device no additional installation space for instance located in driving direction behind a radiator is required. Here, the flow regulating device utilizes the free space which is obtained anyhow upon assembly or upon compilation of individual heat exchangers of the cooling device.

According to an advantageous further development it is provided that seen in driving direction of the vehicle the first heat exchanger is arranged downstream of the flow regulating device and the second heat exchanger is arranged upstream of the flow regulating device. Here it is more preferably provided to design the first heat exchanger as radiator which is thermally coupled to a drive unit of the vehicle. The second heat exchanger in this case can be preferentially designed as condenser of a motor vehicle air conditioner. An obverse arrangement according to a further alternative is likewise intended by the invention.

According to a further advantageous configuration the flow regulating device substantially extends in a plane peipendicularly to the driving direction of the vehicle. In this regard, it substantially extends completely over the onflow or throughflow-capable cross-section of the first and/or second heat exchanger.

Thus, the flow regulating device is more preferably designed for the optional blocking or opening of a flow channel through which cooling air can flow. In a closed configuration the flow regulating device can almost completely cut off or separate from a cooling air supply the heat exchanger arranged downstream of said flow regulating device.

According to a further advantageous configuration it is further provided that the flow regulating device comprises a frame through which cooling air can flow, on which at least one actuator changing the throughflow-capable cross-sectional area of the regulating device is displaceably and/or pivotably arranged. Thus, more preferably pivotable fins or flaps and a not substantially throughflow-capable areal structure displaceable over the area of the frame can be arranged on the frame.

The actuator or a plurality of actuators in this case can either completely open the throughflow-capable cross-sectional area or close said cross-sectional area completely or only partially. Here, more preferably a continuous adjustment of the actuator is provided so that a cooling capacity that is adaptable to the respective cooling requirements can be provided by the cooling device.

According to an advantageous further development it is additionally provided that the frame comprises a lattice structure having at least two components with a front lattice and a rear lattice. The individual lattice components in this case are substantially arranged in an overlapping manner relative to each other. Front and rear lattice are additionally arranged one after the other seen in vehicle longitudinal direction or in driving direction and form a support structure for an individual actuator or for a plurality of variably adjustable actuators. Through the arrangement substantially overlapping each other of front and rear lattice the flow resistance of the lattice structure can be kept as low as possible despite an arrangement extending over the entire flow cross section.

According to a further preferred configuration the actuator in this case is designed as a roller blind displaceable between front and rear lattice. In so far as that is concerned the actuator comprises an areal structure that can be rolled up or wound up which can be substantially designed impermeable to cooling air. Here, the extension or the space requirement of the roller blind parallel to its areal normal in the unwound state proves advantageous. For a roller blind together with a correspondingly narrow frame structure in vehicle longitudinal direction can be placed in the intermediate space between condenser and radiator of the cooling device without problem.

In that the roller blind on both sides, namely in each case towards the adjacent heat exchangers located upstream and downstream is encased by a lattice any possible deformations or flapping of the roller blind can be effectively counteracted. Dynamic pressure bearing against the roller blind occurring in driving operation can be absorbed by the supporting lattice without substantial deformation of the roller blind. The encasing of the roller blind on both sides between front and rear lattice additionally prevents a potential damaging of the roller blind through dynamic pressure.

Here it is of particular advantage if the winding roller or the winding shaft of the roller blind comes to lie outside that intermediate space of the heat exchangers. According to a further development of the invention it is more preferably provided that the winding shaft is arranged on an upper end portion of the lattice structure and thereby, seen in vehicle vertical direction, protrudes from an upper end portion of at least one of the heat exchangers. In this way the roller shaft itself, seen in vehicle longitudinal or vehicle transverse direction, can come to lie at least in portions in an overlapping manner with the first and/or the second heat exchanger. In addition, the alignment of the winding shaft in vehicle transverse direction has the advantage that unwinding of the roller blind can take place under the effect of the weight force of an unwindable end portion of the roller blind.

Depending on the adhesive or sliding friction resistance of the roller blind within the lattice structure, unwinding of the roller blind can even take place entirely without separate driving device, solely due to the weight force of the free roller blind end.

Merely for winding up the roller blind would the help of a drive be required.

Thus, the winding shaft and/or the guide strip are operationally connected to a drive for winding up and/or unwinding the roller blind. Here, the drive can either act directly on the winding shaft or be operationally connected to a guide element separately fastened to the roller blind with a force transmission means transmitting a pulling or pushing force.

According to a further advantageous configuration the actuator comprises an areal structure with passage openings for cooling air spaced from one another. Thus the roller blind can more preferably comprise individual passage openings corresponding to the lattice structure preferentially spaced equidistantly from one another, so that even with closed roller blind a minimum air supply to the heat exchanger located behind said roller blind in driving direction can be provided.

The size as well as the geometrical distribution of individual passage openings in this case can be adapted to the geometrical targets and particularities of the respective heat exchanger and of the flow channel conducting the cooling air.

According to a further advantageous configuration the front lattice and the rear lattice can be positively connected to each other. More preferably it is hereby provided that the connection of the two lattices to be substantially arranged in an overlapping manner relative to each other is effected by means of latching or clipping connection in their marginal region.

Holding or latching means provided for this purpose can be preferably formed in one piece with the respective lattices or be molded thereon.

In addition to positive connecting means for the front and the rear lattice other connections such as for example rivet or screwing connections of the lattice components can also be implemented. In addition, the lattice components can be produced as injection molded parts, for instance of glass fiber-reinforced thermoplastic, such as for example polyamide with an at least 40-percent glass fiber component. In addition it is -10 -conceivable to design the lattice structure or at least components thereof as die casting components or light metal extruded components. Possible suitable light metals in this case are more preferably aluminum or magnesium.

It can also be provided to combine individual metal casting or extruded parts with plastic injection molded parts in hybrid construction.

According to a further advantageous configuration it is provided that the front and/or the rear lattice at an upper marginal portion comprise/s a mounting or a covering for the winding shaft. To that extent the lattice structure can comprise an integrated mounting or covering for the winding shaft of the roller blind. The winding shaft with roller blind wound up thereon to that extent has to be merely inserted rotatably mounted into that lattice-end mounting during a final assembly.

Here it can be additionally provided that mounting or covering preferably provided on an upper edge of the lattice structure is simultaneously provided with a sealing element, with which the lattice frame supports itself as air-tight as possible on an air guiding device adjoining to the outside. The provision of a sealing element in this case is not restricted to the region of the winding shaft. The lower as well as lateral end portions of the lattice frame can each also be provided with a preferably strip-like sealing element, which in each case upon reaching of a final assembly configuration supports itself on a marginally adjoining air guiding device preferably in an airtight manner.

-11 -Through that quasi sealing arrangement of the lattice frame guiding the roller blind on adjoining air guiding devices it can be advantageously achieved that the cooling air fed in via a flow channel and flowing through the second heat exchanger is almost completely dammed-up and with opened roller blind flows onto the heat exchanger, preferably the radiator or the cooling device located downstream of the flow regulating device without any pressure loss worth mentioning. I0

According to a further advantageous configuration of the invention it is additionally provided that an end portion of the roller blind that can be unwound from the winding shaft is provided with a guide strip. On the one hand, the guide strip through its weight force can assist unrolling of the roller blind. In addition, the guide strip on both of its end portions can be separately guided on the lattice frame. There it is additionally conceivable to couple the end portions of the guide strip with a drive so that rolling up and unrolling of the roller blind can be effected via a displacement movement of the guide strip initiatable by a drive. The guide strip ends in this case can for example be coupled to a screw, cable or chain drive.

In addition, a rotary spring element would be preferably provided on the winding shaft by means of which the roller blind can be wound up.

In addition to a cooling device the invention furthermore relates to a motor vehicle that is equipped with a cooling device according to the invention.

-12 -

Brief description of the figures

Further objectives, features and advantageous configurations of the inventions are explained in the

following description making reference to the

drawings. Here, all features mentioned in the text and also shown in the Figures both by themselves as well as in any practical combination form the subject of the invention.

It shows: Fig. 1 an isolated perspective representation of the cooling device according to the invention, Fig. 2 a perspective representation of the cooling device in an installation situation on the vehicle, Fig. 3 a vertical cross section along the cross-section line A-A according to Fig. 2, Fig. 4 an enlarged detail of the cross section according to Fig. 3, Fig. 5 a horizontal cross section through the arrangement according to Fig. 2 along B-B, Fig. 6 an enlarged representation of the right margin of the cross section according to Fig. 5, Fig. 7 an isolated perspective representation of the flow regulating device, -13 -Fig. 8 an exploded representation of the individual components of the flow regulating device, Fig. 9 an isolated perspective representation of a wound-up roller blind and Fig. 10 an unwound roller blind.

Detailed description

The cooling device 10 shown in Fig. 1 and 2 in perspective representation comprises a plurality of heat exchangers such as for example a charge air cooler 12, a dryer 14 of a vehicle air conditioner, a condenser 16 of the vehicle air conditioner and a radiator 30 located behind the condenser 16 and not explicitly shown in Fig. 1. While the condenser 16 and the dryer 14 are part of the climate circuit of the vehicle and through which a refrigerant can accordingly flow, the radiator 30 is in thermal contact with the drive unit, preferentially the combustion engine of the motor vehicle. By contrast, the charge air cooler 12 is coupled to a turbocharger.

The radiator 30 shown in cross section according to Fig. 5 and 6 comprises a cooling water tank 18 on its end portion lying in vehicle transverse direction which is constructed comparatively wide in vehicle longitudinal direction. This cooling water tank seen in vehicle longitudinal direction protrudes at least to a minor extent over the radiator 30 so that with an arrangement of condenser 16 and radiator 30 located one after the other in vehicle longitudinal direction an intermediate space 48 shown enlarged in Fig. 6 is inevitably created.

-14 -The cooling device 10 shown separately in Fig. 1 is to be fastened to a front structure 26 of the vehicle body according to Fig. 2. For the controlled and effective onflow of the individual heat exchangers 12, 14, 16, 30 with supplied cooling air a lateral and circumferential cooling air guide 28 is additionally provided in this case, which encloses the cooling device in the final assembly situation on the front structure region of the vehicle body at least in certain regions.

The cooling air flow branched-off from the headwind or generated by a fan separately provided for this purpose initially flows through the condenser 16 mounted upstream in driving direction and subsequently through the radiator 30 arranged behind.

Upon or after the passage through those heat exchangers 12, 16, 30 the cooling air is sometimes subjected to quite severe swirling, which can noticeably impair the aerodynamics of the motor vehicle, particularly in a high speed range.

To improve the vehicle aerodynamics a flow regulating device 20 is provided in the intermediate space 48 between condenser 16 and radiator 30, which substantially extends over the entire throughf low-capable cross section of the intermediate space 48 between condenser 16 and radiator 30. The flow regulating device comprises a lattice structure 40 shown in Fig. 7 and Fig. 8 whose cross-sectional area through which cooling air can flow is variable with respect to its permeability to cooling air.

In the configuration shown in Fig. 7 to 10 it is more preferably provided here to provide a winding shaft 34 on the upper margin of the lattice structure 40, on which a roller blind 36 that can be unwound downwards -15 -is wound up. The winding shaft 34 in this case can be directly provided with an electric motor drive 22 which through a corresponding activation can transfer the roller blind 36 into an unwound and thus unfurled configuration shown in Fig. 10 or into a wound-up configuration thus opening the throughf low-capable cross section shown in Fig. 9.

The drive 22 in this case is provided with a plug 52 in order to simplify its electrical contacting.

It is furthermore conceivable to transfer the roller blind 36 variably and continuously into part-opened positions located in between.

The roller blind 36, as separately shown in Fig. 8, is mounted between two inter-corresponding lattice structures 42, 44 in a displaceable or roll-up-capable manner. A front lattice 42 in this case corresponds to a rear lattice 44. The two lattices can be directly connected to each other subject to mounting the roller blind arrangement 20 in a mounting 50 arranged on the upper end portion of the front lattice 42 provided for this purpose.

Connecting the two lattices 42, 44 lateral clips or similar fastening means 46 are provided for example on the front lattice 42. The front lattice 42 also has a fastening strap 24 standing away in vehicle transverse direction, by means of which the flow regulating device 20 shown in a pre-assembled manner in Fig. 7 can be fastened to the cooling device, for example on the cooling water tank 18, as is indicated for example in Fig. 1.

At its upper end portion the rear lattice 44 also comprises a kind of latching lug 56, by means of -16 -which the rear lattice 44 can for example be fastened to the lateral strap 24 of the front lattice 42.

In that the roller blind that can be wound up onto the winding shaft 34 is displaceably arranged between two inter-corresponding lattice structures 42, 44 a deformation impairing the functionality of the roller blind web 36 can be largely prevented even upon occurrence of a substantial dynamic pressure on the roller blind 36.

The roller blind 36 can additionally comprise individual passage openings 38 as is evident from Fig. 4 and 10. Here, the passage openings 38 with a completely run-down roller blind 36', as for example shown in Fig. 10, come to lie in the region of the lattice intermediate spaces. Thus, even with a roller blind 20 still located in closing position, a minimum of cooling air can still be supplied to the radiator 30 located behind.

With unwound roller blind 36' a dynamic pressure can be generated in the region of the lateral cooling air guide 28 so that the cooling air branched off the headwind laterally flows past the cooling device 10 which under aerodynamic aspects proves more favorable than flowing through and swirling through the various heat exchanges 12, 16, 30.

The roller blind 36 furthermore comprises a guide strip 54 at its end portion facing away from the winding shaft 34, which on the one hand through its weight force supports an unrolling of the roller blind 36 from the winding shaft 34. In addition, the guide strip 54 keeps the roller blind 36 tensioned in the completely or partially lowered configuration.

-17 -In addition, by way of a lateral guide of the guide strip not explicitly shown in the Figures, for example on the lattice structure 40, the roller blind 20 can be wound up or unwound, for example in that end portions of the guide strip 54 located in vehicle transverse direction are coupled to suitable drive means, for example with a cable pull, a chain drive or a spindle drive. In this case, a spring element preferably is to be provided in the region of the winding shaft 34 which with diminishing downward pulling force on the guide strip 54 winds up the roller blind 36 in a self-acting manner.

The lattice structures 42, 40 shown in Fig. 8 and in Fig. 7 in the assembled state are preferably designed as injection molded parts. Temperature-resistant plastics such as glass fiber-reinforced polyamide but also light metals such as aluminum are possible as suitable material for the guide lattice 40.

Preferably an elastic sealing lip 32 is to be provided on the lower end portion of the front lattice 42 by means of which the lattice structure largely supports itself in a sealing manner on the charge air cooler 12, as is evident for example from the cross section according to Fig. 4. Here it is additionally shown that front lattice 42 and rear lattice 44 are positively inter-latched in the lower marginal region. In addition, the flat roller blind 36 comes to lie between the lattice bars of front lattice 42 and rear lattice 44.

In the cross section according to Fig. 3 it is additionally evident that the mounting 50 located at the top and arching backwards strip-like simultaneously acts as sealing element for the winding shaft 34, with which the lattice structure 40 supports itself upwards on the -18 -air guiding device 28 preferably in an air-sealing manner.

The mounting 50 in this case can be more preferably unitarily joined to the front lattice structure 42. In the cross section according to Fig. 5 and 6 a lateral clip 46 is additionally shown, with which front and rear lattice 42, 44 are positively held together.

The represented embodiments merely show possible configurations of the invention to which numerous additional versions are conceivable and are within the scope of the invention. The exemplarily shown exemplary embodiments must not under any circumstances be interpreted as restrictive with respect to the scope, the applicability or the configuration possibilities of the invention. The present description merely shows the person skilled in the art a possible implementation of an exemplary embodiment according to the invention. On the function and arrangement of described elements a great variety of modifications can be carried out without leaving the scope of protection or its equivalent defined by the following Patent Claims.

-19 -List of reference numbers 10 Cooling device 12 Charge air cooler 14 Dryer 16 Condenser 18 Cooling water tank 20 Flow regulating device 22 Drive 24 Fastening means 26 Front structure component 28 Cooling air guide 30 Radiator 32 Seal 34 Winding shaft 36 Roller blind 38 Passage opening 40 Lattice structure 42 Lattice 44 Lattice 46 Latching means 48 Intermediate space 50 Mounting 52 Plug 54 Guide strip 56 Latching lug