Signaling system for mounting on the roof of a motor vehicle and motor vehicle

Abstract

Signaling system (1) for giving at least one special signal and for mounting on a roof (5) of a motor vehicle (2), comprising a housing (4) having low flow resistance and a signaling unit (3) arranged inside the housing (4) and designed for giving special signals, wherein the housing (4) has a housing side (4a) facing the motor vehicle (2) and adapted to the roof (5) and a housing side (4b) facing away from the roof, wherein the housing side (4b) facing away from the roof (5) corresponds to the suction side (106) of an airfoil (12), characterized in that the housing side (4a) facing the roof (5) has an elastic layer (10) designed to compensate for the shape of the roof (5).

Description

[0001] The present invention relates to a signaling system for emitting at least one special signal and for mounting on the roof of a motor vehicle. Furthermore, the present invention relates to a motor vehicle.

[0002] Emergency vehicle signaling systems designed to emit special signals are typically mounted on the roof of the vehicle. Mounting the signaling system on the roof of the vehicle has the primary advantage of being clearly visible to other road users. This allows other road users to be warned early about the emergency vehicle's special right of way.

[0003] However, placing the signaling system on the roof of an emergency vehicle has the disadvantage of increased aerodynamic drag for the entire vehicle. Particularly with regard to electrically powered police vehicles, vehicle manufacturers strive to reduce aerodynamic drag as much as possible. The primary focus here is on the range of the electrically powered emergency vehicle. Another aim of manufacturers is to increase the top speed of the emergency vehicle. To ensure that fast vehicles can always be pursued, reducing aerodynamic drag is also advisable. With increased mileage of an emergency vehicle equipped with a signaling system, a significant increase in fuel consumption can be observed. Furthermore, the turbulence created by the signaling system has a negative impact on driving characteristics.

[0004] Reducing air resistance has already been addressed in several documents. Since the lamp units of signal systems have only become increasingly smaller in recent years, the structure of an emergency vehicle's signal system is still typically bulky. US Pat. No. 4,334,211 A attempts to avoid air turbulence on such bulky signal systems by generating turbulence on the side of the signal system facing the direction of travel. The superposition of the turbulence thus generated with the eddies of the air flow reduces the air resistance of the entire vehicle. WO 2014 / 195732 A2 takes a different approach. This reduces air resistance by reducing the cross-sectional area in the direction of travel. However, both disclosures have in common that they are mounted on the roof in such a way that air can flow between the signal system and the roof.

[0005] DE 203 10 472 U1 discloses a signaling system with a housing whose side facing the roof is directly attached to the roof, preventing air from flowing between the signaling system and the roof. The shape of the housing of the signaling system in DE 203 10 472 U1 is also designed to further minimize air resistance.

[0006] US 7 825 790 B2 pursues a completely different approach. In this disclosure, the signaling system is integrated into the roof of the emergency vehicle. The signaling system of the emergency vehicle is designed such that, when in use, the signaling system is extended from the roof and retracted back into the roof after use. In one embodiment of the signaling system described in US 7 825 790 B2, the air resistance in the extended state can be reduced by varying the angle of the flat housing relative to the vehicle roof. Air resistance is lowest when the signaling system is concealed in the roof when not in use.

[0007] Furthermore, DE 692 010 A, DE 10 2007 048 226 A1 and DE 197 44 717 A1 each disclose a signaling system with a signaling unit designed to emit at least one special signal.

[0008] The object of the present invention is to provide an advantageous signaling system for emitting at least one special signal and for mounting on the roof of a motor vehicle. A further object of the present invention is to provide a motor vehicle required for using the signaling system.

[0009] The first object is achieved by a signaling system according to claim 1, and the second object is achieved by a motor vehicle according to claim 11. The dependent claims contain advantageous embodiments of the present invention.

[0010] According to the invention, a signaling system for emitting at least one special signal and for attachment to a roof of a motor vehicle is provided. The signaling system comprises a housing whose design provides low flow resistance in an airflow. Furthermore, the signaling system comprises a signal unit arranged within the housing, which is designed to emit special signals. The housing has at least two housing sides, with one housing side facing the roof and the other housing side facing away from the roof. The side facing the roof is adapted to the shape of the roof. The housing side facing away from the roof corresponds to the suction side of an airfoil. The motor vehicle can be an emergency vehicle of the police, the fire department, or a private security service.

[0011] The signaling system is directly connected to the roof, preventing air from passing between the signaling system and the roof. An elastic layer is arranged between the signaling system and the roof. This elastic layer compensates for the different roof shapes of individual roof types, allowing the housing side of the signaling system facing the roof to adapt to the roof shape.

[0012] According to one embodiment of the present invention, the housing side of the signaling system facing away from the roof corresponds to the suction side of a NACA airfoil. NACA airfoils are two-dimensional cross-sections of aircraft wing profiles. NACA stands for "National Advisory Committee for Aeronautics." NACA airfoils represent different starting profiles for the designs of further wings. The NACA airfoils themselves are variations of an original airfoil. Wing developments, particularly in the early days of aviation history, were mostly based on NACA airfoils. The signaling system of the present invention preferably has a housing whose housing side facing away from the roof corresponds to the suction side of a NACA airfoil 8416.

[0013] While a motor vehicle is moving, an air flow is generated. The structure of a modern motor vehicle is designed such that the air flow is usually directed in a laminar manner past the roof of the vehicle. This creates low-pressure zones, particularly behind edges where the direction of the air flow changes. According to one embodiment of the present invention, the signaling system is arranged in one of these low-pressure zones. According to a further embodiment of the present invention, the edge of the signaling system facing the direction of travel is spaced between 0.45 m and 0.60 m from the edge of the windshield facing away from the direction of travel.

[0014] According to one embodiment of the present invention, air resistance is further reduced by providing the housing side facing away from the roof of the motor vehicle with a rough layer designed to reduce lift. By creating small turbulences, the lift caused by the shape of the signaling system's housing is reduced again. The rough layer is transparent. The light from the signaling unit within the housing is thus not absorbed by the rough layer. According to another embodiment of the present invention, the rough layer can have a Reynolds number greater than 300,000.

[0015] In order to prevent damage to the paintwork of the roof, according to one embodiment of the present invention a fleece layer is arranged between the housing side facing the roof and the roof.

[0016] According to one embodiment of the present invention, the distance between the housing and the windshield depends, on the one hand, on the vehicle type. On the other hand, this distance depends on an angle defined between the windshield and a central roof profile. A central roof profile is defined by averaging the actual roof profile along the direction of airflow.

[0017] According to one embodiment of the present invention, the signal unit in the housing of the signaling system comprises a blue light unit and a follow-up tone horn.

[0018] The housing of the signaling system according to the invention has end faces, each of which houses a fastening device. These fastening devices are designed to attach the signaling system to the roof of a motor vehicle.

[0019] Furthermore, the present invention provides a motor vehicle with a signaling system according to the invention.

[0020] Further features, properties and advantages of the present invention will become apparent from the following embodiment with reference to the accompanying figures. Fig. 1 shows an emergency vehicle with a signaling system according to the invention, which is mounted on a roof of an emergency vehicle. Fig. 2 shows the emergency vehicle with the signaling system according to the invention, in which Fig. 2 the air flow over the roof of the vehicle is also shown. Fig. 3 shows a side view of an emergency vehicle with a signaling system according to the invention. Fig. 4 shows a housing of a signaling system according to the invention, wherein only the area of ​​the housing of the signaling system facing the direction of travel is shown. Fig. 5 shows the signaling system according to the invention in a front view, with only the driver's side being shown. Fig. Figure 6 shows a cross-section of an airfoil corresponding to the NACA 8416 profile. Fig. 7 shows a cross section of a housing of a signaling system according to the invention.

[0021] An embodiment of the signaling system according to the invention for emitting at least one special signal and for fastening on a roof of a motor vehicle is described below with reference to the figures.

[0022] The signaling system 1 according to the invention is mounted in the present embodiment on a police vehicle 2, as shown in Fig. 1. Especially with police vehicles 2 it is extremely important that the motor vehicles 2 can reach a speed appropriate to the person being pursued and that they have driving characteristics that allow a pursuit to be carried out to the end. Both of these vehicle characteristics are influenced by air resistance. In addition to the vehicle characteristics already mentioned, air resistance also influences the fuel consumption of the motor vehicles 2 and thus the economic efficiency of the emergency vehicles 2. In addition, the demand for electric emergency vehicles 2 is increasing. Since the ranges of electric emergency vehicles 2 are still very limited compared to the ranges of motor vehicles 2 with petrol or diesel engines, great efforts are being made to minimize the air resistance of the emergency vehicles 2 as much as possible.

[0023] The police vehicle 2 in the exemplary embodiment of the present invention has a signaling unit 3 in which a blue light unit and a siren are integrated. The signaling unit 3 is designed to emit special signals. This signaling unit 3 is mounted in a housing 4 of a signaling system 1 on the roof 5 of the police vehicle 2. The housing 4 of the signaling system 1 is connected at the front sides to the roof 5 of the emergency vehicle 2 via a fastening device 7, as shown in Fig. 5 can be clearly seen. The housing 4 of the signaling system 1 has a low flow resistance in the direction of travel 101. The housing side 4a of the signaling system 1 facing the roof 5 is connected to the roof 5 of the emergency vehicle 2 in such a way that no air can flow between the roof 5 and the signaling system 1. In order for the signaling system 1 to be mounted on different types of emergency vehicles 2, in the present exemplary embodiment there is an elastic layer 10 between the housing 4 of the signaling system 1 and the roof 5 of the emergency vehicle 2 (cf. Fig. 4). Furthermore, a fleece layer 11 between the housing 4 of the signaling system 1 and the roof 5 of the emergency vehicle 2 prevents scratching of the paintwork of the emergency vehicle 2.

[0024] The special feature of the present invention is the housing side 4b of the signaling system 1 facing away from the roof 5. The housing side 4b of the signaling system 1 facing away from the roof 5 corresponds to the suction side 106 of an airfoil profile 12. The designs of the housing side 4b facing away from the roof 5 can be modeled on a wide variety of airfoil profiles 12. NACA profiles are preferably used. In particular, the airfoil profile 12 NACA-8416 has a suction side 106, the cross-section of which is very well suited as a template for the cross-section of a housing side 4b facing away from the roof 5 of a signaling system 1 according to the invention. The NACA-8416 profile is in Fig. 6 shown.

[0025] The signaling system 1 according to the invention is mounted on the roof 5 of the emergency vehicle 2 in such a way that the air flowing over the roof 5 is not influenced, so that no additional air turbulence arises. In the present invention, this is achieved by arranging the signaling system 1 in a low-pressure region 102 of the air flow 100. A low-pressure region 102 of the air flow 100 arises, for example, behind edges that are rounded in such a way that the laminar air flow 100 does not break off and no air turbulence occurs. In modern motor vehicles 2, such low-pressure regions 102 arise shortly behind the windshield 6 downstream of the air flow 100 (cf. Fig. 2). In this area, the signaling system 1 is mounted in the exemplary embodiment of the present invention. Typically, a distance 105 of 0.45 m to 0.60 m is maintained between the housing 4 and the windshield 6. However, this distance 105 depends on the vehicle type. Furthermore, this dependency is influenced by the angle 104 between the central roof line and the rise of the windshield 6 (see FIG. Fig. 3). Here, the exact location of the low-pressure region 102 can vary depending on how the air flows laminarly over the roof 5 of the motor vehicle 2. Furthermore, the location of the low-pressure region 102 depends on the speed of the motor vehicle 2.

[0026] In the exemplary embodiment of the present invention, the housing side 4 of the signaling system 1 according to the invention facing away from the roof 5 is covered with a rough layer 103 (cf. Fig.7). This rough layer 103 serves to generate small air turbulences. This ensures that the motor vehicle 2 does not experience any additional lift. In particular, lift is to be prevented by simulating an airfoil profile 12. Above all, lift is to be prevented by simulating a NACA profile, in particular a NACA 8416 profile, which has been optimized for a high suction side 106. This rough layer 103 is also transparent, so that the light generated within the housing 4 of the signaling system 1 can pass through the rough layer 103 without absorption. Furthermore, the rough layer 103 has a Reynolds number greater than 300,000.

[0027] The present invention has been described in detail using an exemplary embodiment for illustrative purposes. However, a person skilled in the art will recognize that deviations from the exemplary embodiment are possible and can be deviated from. For example, in addition to police emergency vehicles, fire department vehicles or private security vehicles can also be used. The invention is therefore not intended to be limited to the exemplary embodiment, but solely by the appended claims. List of reference symbols 1 signaling system 2 motor vehicles 3 Signal unit 4 housings 4a Housing side facing the motor vehicle 4b Housing side facing away from the motor vehicle 5 Roof 6 Windshield 7 Fastening device 8 middle roof line 10 elastic layer 11 fleece layer 12 Wing profile 100 air flow 101 Direction of travel 102 Low pressure range 103 rough layer 104 angles 105 distance 106 Suction side

Claims

[1] Signaling system (1) for emitting at least one special signal and for fastening on a roof (5) of a motor vehicle (2), comprising a housing (4) having a low flow resistance and a signaling unit (3) arranged within the housing (4) and designed to emit special signals, wherein the housing (4) has a housing side (4a) facing the motor vehicle (2) and adapted to the roof (5) and a housing side (4b) facing away from the roof, wherein the housing side (4b) facing away from the roof (5) corresponds to the suction side (106) of an airfoil profile (12), characterized by that the housing side (4a) facing the roof (5) has an elastic layer (10) designed to compensate for the shape of the roof (5). [2] Signaling system (1) according to claim 1, wherein during the travel of the motor vehicle (2) an air flow (100) arising above the roof (5) of the motor vehicle (2) creates a low-pressure region (102), characterized bythat the signaling system (1) is arranged on the roof (5) within the low-pressure area (102). [3] Signaling system (1) according to claim 1 or 2, characterized by that the housing side (4b) facing away from the motor vehicle (2) corresponds to the suction side (106) of a NACA profile. [4] Signaling system (1) according to one of claims 1 to 3, characterized by that the housing side (4b) facing away from the roof (5) has a transparent, rough layer (103) designed to reduce buoyancy. [5] Signaling system (1) according to claim 4, characterized by that the rough layer (103) has a Reynolds number greater than 300000. [6] Signaling system (1) according to one of the preceding claims, characterized by that the housing side (4a) facing the roof (5) has a fleece layer (11) designed to protect the paintwork of the roof (5). [7] Signaling system (1) according to one of the preceding claims, characterized bythat a distance (105) of 0.45m to 0.60m is maintained between the housing (4) and the windscreen (6). [8] Signaling system (1) according to claim 7, characterized by that the distance (105) between the housing (3) and the windscreen (6) depends on the vehicle type and on an angle (104) between the windscreen (6) and a central roof profile (8). [9] Signaling system (1) according to one of the preceding claims, characterized by that the signal unit (3) has a blue light unit and a follow-up tone horn. [10] Signaling system (1) according to one of the preceding claims, characterized by that the housing (4) has end faces with a fastening device (7) which is designed for fastening the signaling system (1) to a roof (5) of a motor vehicle (2). [11] Motor vehicle (2) with a signaling system (1) according to one of the preceding claims.

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