GB2520626A

GB2520626A - Grille for a vehicle, in particular a commercial vehicle, as well as a vehicle

Info

Publication number: GB2520626A
Application number: GB1418695.1A
Authority: GB
Inventors: Ryan Geary; Michael Norlin; Dinesh Madugundi; Rafael Dos Santos; Michael Gatza; Georgeanna Alemany; Derek James Rotz
Original assignee: Daimler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2014-10-21
Filing date: 2014-10-21
Publication date: 2015-05-27
Also published as: GB201418695D0

Abstract

The invention relates to a grille 12 for a vehicle, in particular a truck, the grille 12 being configured to be arranged in front of at least one heat exchanger of the vehicle and comprising a plurality of grille bars 16 movable between a closed position in which at least a portion 20 of an air passage aperture 14 is covered by the grille bars 16, and at least one open position in which the portion 20 of the air passage aperture 14 is uncovered, wherein at least a portion of the respective grille bar 16 is airfoil-shaped. The grille bars 16 are connected to a shared actuator (28, figure 6) configured to move the grille bars 16 between the closed position and the open position. In the closed position, the grill bars can closely match a shape of an engine hood 10 adjacent to the grille to maximize aerodynamic benefit. The actuator (28) is arranged adjacent to the grille bars 16 in a receptacle (46) covered by at least one cover element, the cover element 24 sitting flush with the grille bars 16 in the closed position of the grille bars.

Description

Grille for a Vehicle, in particular a Commercial Vehicle, as well as a Vehicle The invention relates to a grille according to the preamble of patent claim 1 as well as a vehicle, in particular a commercial vehicle.

Vehicles comprising grilles are well-known from the general prior art. Such a grille is also referred to as a radiator grille" and configured to be arranged in front of at least one heat exchanger of the vehicle. For example, the grille is configured to be arranged at least partially in an air passage aperture through which air can flow due to a forward movement of the vehicle. In other words, the grille can provide air flow so that air can flow against and around the heat exchanger arranged behind the grille with respect to the longitudinal direction of the vehicle.

For example, the heat exchanger serves to cool a fluid due to a heat transfer from the fluid via the heat exchanger to the air flowing around the heat exchanger. This means the fluid can flow through the heat exchanger thereby transferring heat via the heat exchanger to the air flowing around the heat exchanger.

The fluid can be configured as a liquid or a gas. For example, the fluid is a coolant used to cool an engine of the vehicle. Alternatively or additionally, the coolant can be used to cool at least one electrical component of the vehicle. Moreover, the fluid can be a refrigerant used by an air conditioning system to cool air to be guided into an interior of the vehicle.

The grille comprises a plurality of grille bars which are movable between a closed position and at least one open position. In the closed position, at least a portion of said air passage aperture is covered by the grille bars. In the open position, the portion of the air passage aperture is uncovered so that air can flow through the portion. In the closed position, air flow through the portion is prevented.

Moreover, US 8,505,660 B2 shows an apparatus for use with a vehicle grille comprising a frame and a pair of shutters connected to said frame and pivotable relative thereto between a first position and a second position about a pivot axis. Each of said shutters includes an engagement member, the shutters restricting airflow through the vehicle grille in said first position and allowing airflow through the vehicle grille in said second position.

The apparatus further comprises a drive mechanism driving said shutters between said first position and said second position, said drive mechanism including a drive shaft rotating relative to said frame and a drive member engaging said drive shaft. The drive member moves linearly relative to said frame, said drive member including an arcuate slot slidably engaging one of said engagement members. The shutters are connected to said frame for pivotal motion in opposite direction relative to each other between said first and second position.

It is an object of the present invention to provide a grille of the aforementioned kind, by means of which grille particularly advantageous aerodynamics of the vehicle can be realized. It is a further object of the present invention to provide a vehicle having particularly advantageous aerodynamics.

This object is solved by a grille having the features of patent claim 1 and a vehicle having the features of patent claim 7. Advantageous embodiments with expedient and non-trivial developments of the invention are indicated in the other patent claims.

In order to provide a grille of the kind indicated in the preamble of patent claim 1, by means of which grille particularly advantageous aerodynamics of the vehicle can be realized, according to the present invention, at least a portion of the respective grille bar is airfoil-shaped. In other words, each of the grille bars comprises at least a portion which has the shape of an airfoil, wherein air can flow around the respective airfoil-shaped portion due to a forward movement of the vehicle. Thereby, the air flowing around the portions can be guided particularly advantageously so that the air can flow against and around the at least one heat exchanger in a particularly advantageous way, in particular in the open position. Preferably, at least a respective major portion of the respective grille bar is airfoil-shaped.

Furthermore, in the closed position, the grille bars can at least closely match a shape of an engine hood adjacent to the grille to maximize aerodynamic benefit. Thereby, air can be guided around the grille and the hood in an advantageous manner so that drag of the vehicle can be kept particularly low.

The idea behind the grille according to the present invention is that, currently, there is a large disparity between the amount of cooling airflow required during peak loading events such as but not limited to climbing steep grades at slow speeds, compared to during typical highway cruising. Typically, a large grille opening or a large air passage aperture is necessary to cool the heat exchanger and, for example, at least one engine of the vehicle during these infrequent peak loading events. During highway cruising, however, a large fixed air passage aperture is larger than it needs to be, since the cooling air velocity is usually faster and the required heat rejection is less. Such an unnecessarily large air passage aperture increases aerodynamic drag of the vehicle. Also, in cold weather and other situations, the engine can be over-cooled which can decrease fuel economy.

Since, in the grille according to the present invention, the grille bars are movable between the closed position and the open position, the size of the air passage aperture through which air can flow can be adjusted in a need-based manner. For example, during peak loading events the grille bars are in the open position so that the heat exchanger and, for example, the engine of the vehicle can be cooled sufficiently. During typical highway cruising, the grille bars can be closed so that the drag can be kept particularly low.

Preferably, the air passage aperture has a further portion adjacent to the first portion, the further portion being open when the grille bars are in the closed position. Thereby, air can flow through the further portion so that the heat exchanger and the engine of the vehicle can be cooled sufficiently in the closed position of the grille bars. In other words, the grille according to the present invention does not completely close the air passage aperture in the closed position since the heat exchanger still needs a small amount of cooling airflow when cruising at, for example, highway speeds. Thereby, the active grille according to the present invention is protected against cycling at highway speeds, i.e. the grille is protected against opening and closing frequently.

The advantages offered by the present invention arc increased aerodynamic efficiency, and the subsequent improvement in fuel economy and operating costs. Since the grille bars are airfoil-shaped, air flowing against and/or around the grille bars can be guided particularly advantageously both in the closed position and in the open position of the grille bars.

The invention also relates to a vehicle, in particular a commercial vehicle such as a truck, the vehicle comprising a grille according to the present invention. Advantageous embodiments of the grille according to the present invention are to be regarded as advantageous embodiments of the vehicle according to the present invention and vice versa.

Further advantages, features, and details of the invention derive from the following description of a preferred embodiment as well as from the drawings. The features and feature combinations mentioned in the following description of the figures and/or shown in the figures alone can be employed not only in the respective indicated combination but also in any other combination or taken alone without leaving the scope of the invention.

The drawings show in: Fig. 1 a schematic front view of an engine hood and a grille for a commercial vehicle, the grille being arranged in front of a heat exchanger unit of the vehicle and comprising a plurality of grille bars movable between a closed position and at least one open position, wherein at least a portion of the respective grille bars is airfoil-shaped and wherein the grille bars are closed; Fig. 2 a schematic and perspective view of the engine hood and the grille according to Fig. 1; Fig. 3 a schematic front view of the engine hood and the grille, wherein the grille bars are open; Fig. 4 a schematic perspective view of the engine hood and the grille according to Fig. 3; Fig. 5 a further schematic view of the grille according to Figs. 1 and 2; Fig. 6 a schematic perspective view of an actuator configured to move the grille bars between the open position and the closed position, wherein the grille bars are closed; Fig. 7 a further schematic perspective view of the actuator, wherein the grille bars are open; and Fig. 8 a schematic perspective view of springs of the actuator, wherein the grille bars are closed.

In the figures the same elements or elements having the same functions are indicated with the same reference signs.

Figs. 1 and 2 show an engine hood 10 for a vehicle in the form of a commercial vehicle, in particular a truck. The truck comprises a driver's cab and an engine compartment arranged in front of the driver's cab with respect to the longitudinal direction of the vehicle.

The engine compartment is covered by the engine hood 10 at least partially. The truck also comprises an engine arranged in the engine compartment, the engine serving to drive the truck. For example, the engine is configured as an internal combustion engine.

Moreover, Figs. 1 and 2 show a grille 12 of the truck, the grille 12 being also referred to as a "radiator grille". The grille 12 is arranged in front of at least one heat exchanger of the vehicle in the longitudinal direction of the vehicle. For example, the grille 12 is arranged in front of a heat exchanger unit of the truck, the heat exchanger unit being not shown in the figures and comprising a plurality of heat exchangers. For example, the heat exchangers overlap each other and serve to cool fluids flowing through the heat exchangers. For example, at least one of said heat exchangers serves to cool at least one component of a power train and/or at least one electrical component of the truck.

Said component of the power train can be the engine. Alternatively or additionally, at least one of said heat exchangers can be part of an air conditioning system configured to supply the interior of the driver's cab with cooled air. The respective fluid flowing through the respective heat exchanger can be cooled by a heat transfer from the fluid via the respective heat exchanger to air flowing against and around the respective heat exchanger. This airflow can be effected by a forward movement of the truck. In other words, air flows around and against the heat exchangers when the truck moves forward.

As can be seen in Figs. 1 and 2, the grille 12 is arranged in an air passage aperture 14 of the engine hood 10. This air passage aperture 14 is an air inlet through which air can flow so that the heat exchangers arranged behind the grille 12 and the air passage aperture 14 can be supplied with the air flowing through the air passage aperture 14.

The grille 12 comprises a plurality of grille bars 16 which are, for example, inherently stable. The grille bars extend in the transverse direction of the vehicle and are arranged on top of each other in relation to the vertical direction of the vehicle. The grille 12 further comprises lateral mounting elements 18 on which the grille bars 16 are mounted. For example, the grille 12 is attached to the engine hood 10 by the mounting elements 18.

The mounting elements 18 can be seen in Figs. 6 to 8.

The grille 12 is designed as an active grille in which the grille bars 16 are movable between a closed position shown in Figs. 1, 2, 5, 6 and 8 and at least one open position shown in Figs. 3, 4 and 7. In the closed position, a first portion 20 of the air passage aperture 14 is closed or covered by the grille bars 16. Thereby, air cannot flow through the first portion 20. In the open position, the first portion 20 is uncovered so that air can flow through the first portion 20 to the heat exchangers when the vehicle moves forward.

As can be seen in Figs. 1 and 2, the air passage aperture 14 has a second portion 22 adjacent to the first portion 20. The second portion 22 adjoins the first portion 20 in the vertical direction of the vehicle towards the bottom. The second portion 22 is uncovered or open when the grille bars 16 are closed so that air can still flow through the second portion 22 to the heat exchangers when the grille bars 16 are closed. Thereby, the heat exchangers can be sufficiently supplied with air even when the grille bars 16 are closed.

In the present case, the grille bars 16 are pivotable about respective pivot axes between the closed position and the open position, the respective pivot axes extending at least substantially in the transverse direction of the vehicle. Each of the grille bars 16 has, for example, shafts on either side near its leading edge that it rotates on, wherein the respective grille bar 16 is pivotably mounted on the mounting elements 18 via said lateral shafts. Thus, the respective grille bars 16 can pivot about the pivot axis relative to the mounting elements 18. The respective shafts attached to the grille bars 16 are pivotably supported on the respective mounting elements 18 via nylon bushings. In other words, the shafts rotate in nylon bushings mounted on the mounting elements 18.

In order to realize particularly advantageous aerodynamics of the vehicle both in the closed position and in the open position of the grille bars 16, at least a portion of the respective grille bar 16 is airfoil-shape. This means the grill bars 16 have airfoil-shaped profiles. In other words, each of the grille bars 16 has at least a portion which has an airfoil-shaped cross section. Thereby, in the open position, air flowing against and around the grille bars 16 can be guided particularly advantageously so that the air can flow against and around the heat exchangers efficiently thereby keeping the drag particularly low. Moreover, in the closed position of the grille bars 16, the air flowing against the grille 12 can be guided around the grille 12 and the engine hood 10 so that the drag and, thus, the fuel consumption of the vehicle can be kept particularly low.

For example, the grille bars 16 automatically open during peak loading events and slower speeds to maximize cooling airflow through the at least one heat exchanger which is configured as, for example, a radiator. At highway speeds, the grille bars 16 automatically close to reduce aerodynamic drag and increase fuel economy.

In the open position, the grille bars 16 are aligned with the airflow. When the grille bars 16 are closed, they at least closely match the shape of the engine hood 10 to maximize aerodynamic benefit as shown in Fig. 5. For example, in the closed position, the grille bars 16 sit flush with the engine hood 10. Preferably, gaps between and beneath the closed grille bars 16 allow just enough cooling air flow in to the engine compartment so that the engine can be cooled efficiently. As can be seen in Figs. 3 and 4, the grille bars 16 are slightly bent downwards with respect to the open position.

For automatically moving the grille bars 16 between the closed position and the open position, the grille 12 comprises an actuating device 26 shown in Figs. 6 to 8. The actuating device 26 comprises an actuator in the form of a pneumatic cylinder 28. As can be seen from Figs. 6 and 7, the grille bars 16 are connected to the shared pneumatic cylinder 28 so that the plurality of the grille bars 16 can be moved by the single pneumatic cylinder 28. In the present case the grille bars 16 are pivotably connected to the pneumatic cylinder 28 via linkage rods 30a-d.

The pneumatic cylinder 28 comprises a housing 32 in which a piston is arranged. The piston is translationally movable relative to the housing 32 and connected to a piston rod 34. Thus, the piston rod 34 moves together with the piston. Air can be guided into the housing 32 by a hose 36 which is also referred to as a pneumatic line" or an "air hose".

The piston rod 34 is pivotably connected to the rod 30d which is in turn pivotably connected to a lover arm 38. The lever arm 38 is connected to a first one of the shafts in a rotatably fixed manner. Thus, the lever arm 38 and, thus, the shaft and the corresponding grille bar 16 can be rotated by the pneumatic cylinder 28 via the rod 30d.

Moreover, the lever arm 38 is pivotably connected to the rod 30c which is in turn pivotably connected to a lever arm 40. The lever arm 40 is connected to a second one of the shafts in a rotatably fixed manner. Thereby, the second shaft and the corresponding grille bar 16 can be pivoted via the rod 30c, the lever arm 38 and the rod 30d.

Furthermore, the lever arm 38 is pivotably connected to the rod 30b which is in turn pivotably connected to a lever arm 42. The lever arm 42 is connected to a third one of the shafts in a rotatably fixed manner. Thereby, the lever arm 42 and, thus, the corresponding grille bar 16 can be pivoted via the rod 3Db, the lever arm 38 and the rod 30d by the pneumatic cylinder 28.

The lever arm 42 is pivotably connected to the rod 30a which is in turn pivotably connected to a lever arm 44. The lever arm 44 is connected to a fourth one of the shafts in a rotatably fixed manner. Thereby, the lever arm 44 and, thus, the corresponding grille bar 16 can be pivoted by the rod 30a, the lever arm 42, the rod 30b, the lever arm 38 and the rod 30d by the pneumatic cylinder 28.

As can be seen from Figs. 6 to 8, the actuating device 26 is arranged in respective receptacles 46 and 48 adjacent to the grille bars 16 in the transverse direction of the vehicle. The receptacles 46 and 48 per se are open in the longitudinal direction of the vehicle towards the front. However, cover elements 24 are provided, wherein the receptacles 46 and 48 are covered by the cover elements 24 in the longitudinal direction of the vehicle towards the front. In the closed position, the grille bars 16 sit flush with cover elements 24 by means of which the mounting elements 18 are covered in the longitudinal direction of the vehicle towards the front. Moreover, in Fig. 6, said leading edges of the grille bars 16 can be seen, the leading edges being designated with 17.

As can be seen in Fig. 5, in the closed position, the grille bars 16 sit flush with the cover elements 24. Moreover, the cover elements 24 sit flush with the engine hood 10. Thereby, a particularly advantageous aerodynamics of the vehicle can be realized.

For example, the cover elements 24 are reversibly attached to the mounting elements 18 and/or the engine hood 10. This means the cover elements 24 can be detached without destroying the cover elements 24. Thereby, the actuating device 26 is accessible from the front exterior of the vehicle as shown in Figs. 6 and 7.

When air is guided into the housing 32, i.e. when the pneumatic cylinder 28 is pressurized, the piston rod 34 is translationally moved into the housing 32 thereby closing the grille bars 16. When the air inside the housing 32 is guided out of the housing 32, i.e. when the pneumatic cylinder 28 is de-pressurized, at least one spring arranged in the housing 32 moves the piston rod 34 out of the housing 32 thereby opening the grille bars 16.

This moans the pneumatic cylinder 28 comprises at least one spring which is loaded in the closed position of the grille bars 16. For example, the spring is configured as a helical spring. For example, the spring is supported or supportable on the piston on one side and the housing 32 on the other side. When the piston rod 34 is moved into the housing 32, the spring is loaded. For example, the spring is compressed.

Moreover Fig. 8 shows springs 50 of the actuating device 26, the springs 50 being arranged in the receptacle 48. The springs 50 are mounted on the mounting element 18 on one side and the respective shaft of the grille bars 16 on the other side via lever arms 52. The springs 50 are also loaded in the closed position of the grille bars 16. For example, the springs 50 are extended. Thereby, the spring inside the housing 32 exerts a spring force on the grille bars 16 via the piston, the piston rod 34 and the rods 30a-d.

Moreover, the springs 50 also exert respective spring forces on the grille bars 16 when the grille bars 16 are closed.

When the pneumatic cylinder 28 is de-pressurized, the spring inside the housing 32 and the springs 50 can relax at least partially thereby moving the grille bars 16 from the closed position into the open position. This means the respective spring force can move the grille bars 16 or support the movement of the grille bars 16 from the closed position into the open position. Thus, the spring arranged inside the housing 32 and/or the springs 50 act as return springs which open the grille bars 16 when the pneumatic cylinder 28 is de-pressurized. Especially, the springs 50 can help open the grille bars 16. Moreover, the springs 50 can take up slag to help prevent vibration.

Preferably, the pneumatic cylinder 28 is controlled by at least one solenoid valve. This means air can be guided into the housing 32 and out of the housing 32 by at least one solenoid valve. The actuating device 26 is designed with a fail-safe so that if the pneumatic cylinder 28 looses pressure or the solenoid valve looses electricity, the grille bars 16 will fail to the open position. By this fail-safe, possible engine over-heating due to the grille bars 16 stuck closed can be prevented. The control of the solenoid valve is automated so that the cooling requirements of the vehicle are satisfied without the need for driver input.

List of reference signs engine hood 12 grille 14 air passage aperture 16 grille bar 17 leading edge 18 mounting element first portion 22 second portion 24 cover element 26 actuating device 28 pneumatic cylinder 30a-d rod 32 housing 34 piston rod 36 hose 38 lever arm lever arm 42 lever arm 44 lever arm 46 receptacle 48 receptacle spring 52 lever arm

Claims

Claims A grille (12) for a vehicle, in particular a truck, the grille (12) being configured to be arranged in front of at least one heat exchanger of the vehicle and comprising a plurality of grille bars (16) movable between a closed position in which atleasta portion (20) of an air passage aperture (14) is covered by the grille bars (16), and at least one open position in which the portion (20) of the air passage aperture (14) is uncovered, characterized in that at least a portion of the respective grille bar (16) is airfoil-shaped.
2. The grille (12) according to claim 1, characterized in that the grille bars (16) are connected to a shared actuator (28) configured to move the grille bars (16) between the closed position and the open position.
3. The grille (12) according to claim 2, characterized in that the actuator (28) is arranged in a receptacle (46) adjacent to the grille bars (16), the receptacle (46) being covered by at least one cover element (24) in the longitudinal direction of the vehicle towards the front.
4. The grille (12) according to claim 3, characterized in that the cover element (24) sits flush with the grille bars (16) in the closed position of the grille bars (16).
5. The grille according any one of claims 2 to 4, characterized in that the actuator (28) is configured as a pneumatic cylinder (28) configured to move the grille bars (16) between the closed position and the open position.
6. The grille (12) according any one of claims 2 to 5, characterized in that at least one spring (50) is provided, the spring (50) being loaded in the closed position of the grille bars (16) thereby exerting a spring force on the grille bars (16) so as to move the grille bars (16) or support the movement of the grille bars (16) from the closed position into the open position.
7. A vehicle comprising a grille (12) according to any one of the preceding claims, the grille (12) being arranged in front of the heat exchanger.