Noise simulator for a motor vehicle

Abstract

Noise simulator (1) for a motor vehicle (2), comprising at least the following components: - a housing (3) which encloses an interior space (4); - at least one electrically controllable noise source (5) arranged in the interior (4) of the housing (3), wherein at least one of the noise sources (5) is a loudspeaker (12) which is arranged such that the sound-emitting membrane (17) is directed outside the housing (3), i.e. directly towards the environment (9), and the basket of the loudspeaker (12) is fastened to the housing (3) such that the magnet (18) is arranged at least partially in the interior (4) of the housing (3); and - a sound outlet (6) in the housing (3), wherein the housing (3) is designed as a resonance body for at least one of the noise sources (5), wherein the housing (3) comprises a material for tailpipes of an exhaust system, wherein the sound outlet (6) is connected to a pipe (10) arranged in the interior (4) of the housing (3), and wherein the pipe (10) has a bend (11).

Description

[0001] The invention relates to a noise simulator for a motor vehicle, as well as a motor vehicle with such a noise simulator.

[0002] With battery electric vehicles (BEVs), the external noise level becomes unemotional and is dominated by the rolling noise of the tires. Legal requirements for pedestrian warning systems (AVASs) regulate which sounds may be generated in the vicinity of a vehicle. Previous systems use loudspeakers placed behind the bumper. These loudspeakers are limited in their volume and sound quality. Emotions are not evoked. Publications addressing this issue include US 10,471,892 B2 and US 9,699,535 B2.

[0003] DE 10 2007 003 201 A1 relates to a device for generating audio signals. Electric or hybrid vehicles operate extremely quietly. In order to design such vehicles so that they can be reliably heard by road users, the device is intended for installation in silent or almost silent vehicles. It generates at least one audio signal audible to other road users. For example, a pedestrian walking on a street, oblivious to traffic, can clearly hear the otherwise very quiet vehicle due to the use of the audio signal, thus effectively warning them of the approaching vehicle. The device is suitable for installation in almost silent vehicles, whereby the audio signal can be generated, for example, by tones, sounds, noises, or the like via an audio generator.

[0004] JP 2008 031936 A relates to a speaker device with good weather resistance and a noise suppression device that effectively suppresses noises generated during the circulation of a fluid in a separate body, such as an exhaust system component. The speaker device consists of an actuator disposed in a sealed space formed by connecting a peripheral edge of a vibrating plate portion to an end portion of a peripheral wall, which is an open end of the enclosure. When the actuator operates, a flat vibrating plate vibrates in the plate thickness direction to generate a plane wave as a sound wave.

[0005] DE 10 2010 005 138 A1 relates to a motor vehicle and an exhaust system for a motor vehicle. The disclosure relates to a motor vehicle with an electronic sound generation system comprising at least one electrical vibration exciter mounted on a baffle that is acoustically decoupled from a body and / or frame of the motor vehicle in such a way that sound is radiated from the baffle into the surroundings of the motor vehicle, as well as to an exhaust system for such a motor vehicle.

[0006] DE 20 2015 104 854 U1 relates to a weight-reduced exhaust tailpipe comprising an inner pipe, a weight-reduced outer pipe and a front attachment, wherein in one embodiment the weight-reduced outer pipe and / or the front attachment is made of titanium.

[0007] CN 2750414 Y relates to a sound effect device for imitating the engine speed transmission sound or the exhaust sound of an automobile. The sound effect device consists of a sound source, a controller, an amplifier, and a horn. The sound source, located in the automobile, can emit the imitated low-pitched engine speed transmission sound or the exhaust sound through the horn. The change in the output sound is controlled by adjusting the controller according to different operating ranges, thereby avoiding noise generation and achieving wonderful and attractive results.

[0008] Based on this, the present invention is based on the object of at least partially overcoming the disadvantages known from the prior art. The features of the invention are derived from the independent claims, for which advantageous embodiments are presented in the dependent claims. The features of the claims can be combined in any technically reasonable manner, whereby the explanations from the following description as well as features from the figures, which comprise additional embodiments of the invention, can also be consulted for this purpose.

[0009] This problem is solved by the features of the independent claims.

[0010] The invention relates to a noise simulator for a motor vehicle, comprising at least the following components: - a housing enclosing an interior space; - at least one electrically controllable noise source arranged in the interior of the housing; and - a sound outlet in the housing, wherein the housing is configured as a resonance body for at least one of the noise sources.

[0011] The noise simulator is characterized in particular in that the housing comprises a material for tailpipes of an exhaust system, wherein the sound outlet is connected to a pipe arranged in the interior of the housing.

[0012] Unless explicitly stated otherwise, ordinal numbers used in the preceding and following descriptions serve only to clearly distinguish them and do not reflect the order or ranking of the designated components. An ordinal number greater than one does not necessarily imply that another such component must be present.

[0013] This proposal proposes a sound simulator for a motor vehicle, which forms a resonance body made from a material used for the tailpipes of a (conventional) exhaust system. Traditional materials for exhaust systems are dictated by the requirements (primarily temperature resistance) of an exhaust system for an internal combustion engine, but they have shaped the perception of sound and the corresponding emotions of vehicle enthusiasts. By arranging an electrically controllable sound source within a housing, for example, the magnet for the voice coil of the diaphragm of a cone speaker, realistic (i.e., combustion-like) exhaust sounds can be generated.The resonator, formed by the housing, the interior, and the sound outlet, functions as a sound amplifier. Furthermore, the material used creates a specific sound coloration, which, depending on the choice of material, closely approximates, or even identifies, the emotional impact of car enthusiasts. In a preferred embodiment, the sound outlet is visually designed like one or more tailpipes.

[0014] The electrically controllable noise source comprises a loudspeaker, wherein the loudspeaker is arranged such that the sound-emitting membrane is directed outside the housing, i.e., directly toward the surroundings, and the loudspeaker's basket is attached to the housing such that the magnet (and preferably also the voice coil) is at least partially arranged within the interior of the housing. Sound emission from the magnet is thus absorbed within the interior of the housing.

[0015] Here, it is further proposed that the sound outlet be connected to a tube, the tube having a predetermined length and shape tuned for the most realistic sound generation possible (at a predetermined resonant frequency). The length is determined, for example, by reflected sound waves from the back of a magnetically controlled loudspeaker.

[0016] It is further proposed in an advantageous embodiment of the noise simulator that the material of the housing comprises titanium, wherein preferably the housing comprises two half-shells, wherein at least one of the half-shells is made of titanium, particularly preferably by means of forming.

[0017] Due to its low density and high elastic modulus, titanium exhibits characteristic resonance properties. In one embodiment, a titanium membrane is incorporated into the housing, for example, forming part of a wall. In one embodiment, the titanium is used as a sheet material.

[0018] In a particularly preferred embodiment, the housing comprises two half-shells that enclose the interior, although it is not excluded that additional elements are used to enclose the interior. For example, a separate element is inserted between the two half-shells for the sound outlet. In a particularly preferred embodiment, the two half-shells correspond to the shape of a conventional tailpipe or a distribution chamber and / or a silencer of a conventional exhaust system.

[0019] In a preferred embodiment, one or both half-shells are made of titanium, so that the half-shells determine or at least dominate the characteristics of the resulting resonator. In a particularly preferred embodiment, at least one of the half-shells is formed by (preferably cold) forming, for example, deep drawing. Ribs are preferably formed here, which influence the sound characteristics (comparable to bridges in a resonator of a musical instrument) by reflecting and / or stiffening the respective half-shell.

[0020] It is further proposed in an advantageous embodiment of the noise simulator that, during use, the sound outlet is directed towards the surroundings of a motor vehicle.

[0021] The proposal here is that the sound simulator can be attached to a motor vehicle in such a way that the sound outlet is directed towards the vehicle's surroundings. This sound simulator is thus designed so that passers-by (in traffic) or spectators (at a car race) can perceive this soundscape. On the other hand, the driver in the vehicle's cab perceives the sounds as coming from outside, so that they seem particularly realistic to him and thus evoke the corresponding emotions. Thus, not only the sound simulator itself and the resonance body it forms are used for the sound simulation, but also the other components of the vehicle, which ensure that sound is transmitted into the driver's cab (preferably in a conventional manner) and pass this noise on to the driver's cab as structure-borne sound.The noise simulator proposed here can be designed in such a way that the sound pressure, i.e. the volume, is as high as that generated in corresponding motor vehicles, in particular sports cars and racing cars, with internal combustion engines.

[0022] According to the invention, it is proposed that the pipe has a bend, particularly preferably of 90°.

[0023] In a preferred embodiment, the housing comprises several separate chambers, wherein the tube is open to one of these (e.g., first) chambers (e.g., with an inlet opening) and is closed in another (e.g., second) chamber up to the sound outlet, for example, as a closed tube. In the (second) chamber, through which the tube runs in a closed state, a vibrator (also referred to as a shaker) is provided, for example, which modulates the resonance properties of the housing (or its walls) by means of controlled vibration or passive excitation.

[0024] According to the invention, the pipe has a kink or bend, preferably with an (approximately) constant pipe diameter, which achieves additional modulation of the simulated sound, for example through reflection properties. Such a kink is preferably formed at 90° [ninety degrees out of 360°]. Thus, the pipe itself, on the sound outlet side, is used as a reflector for the sound waves entering at different angles.

[0025] The tube is preferably designed at a distance from the housing wall (except for the exit at the sound outlet), so that rattling noises are avoided and / or the tube does not influence the resonance properties of the housing, at least not with its mass. Alternatively, the tube is supported on the housing (preferably at specific points) using a rubber-elastic material.

[0026] It is further proposed in an advantageous embodiment of the noise simulator that the noise source comprises at least one of the following components: - a loudspeaker; - a structure-borne sound transducer; and - a manifold pipe, preferably a multiple pipe.

[0027] Alternatively or additionally, one embodiment provides a structure-borne sound transducer in which a predetermined elastically movable suspended mass is arranged in the interior of the housing or with an effect on the interior of the housing (e.g., on the outside). The structure-borne sound transducer is either actively controlled, i.e., electrically controllable, e.g., by means of a magnet, or passively configured to modulate the resonant frequency of the housing. In an arrangement of multiple chambers within the housing and a tube, as described above, the structure-borne sound transducer is preferably arranged in the (second) chamber in which the tube runs in a closed manner and preferably where the tube is connected to the sound outlet.

[0028] Alternatively or additionally, one embodiment provides a manifold pipe through which at least a portion of the sound waves is guided, preferably toward the sound outlet. In a preferred embodiment, a multiple pipe is provided, wherein each of the sub-pipes of the multiple pipe is particularly preferably assigned a loudspeaker, preferably its respective magnetic coil (with the membrane facing outward from the housing), so that the input opening of the sub-pipe arranged in the interior is close to the loudspeaker or directly connected to the loudspeaker.A loudspeaker corresponds, for example, to one (single) or several cylinders (combustion chambers) of a larger number of cylinders of a piston engine in the sense that the (characteristic) gas expansions occurring in such a combustion chamber are reproduced by the loudspeakers as sound and by means of the multiple pipe these (individual) sound emissions are mixed together, very similar to the noise emission of a piston engine with a conventional exhaust system.

[0029] According to a further aspect, a motor vehicle is proposed, comprising a drive engine for propelling the motor vehicle, and a noise simulator according to an embodiment according to the above description for generating ambient noise.

[0030] The motor vehicle is, for example, a passenger car, preferably a sports car or racing car, wherein a drive engine is provided to propel the motor vehicle. The drive engine is, for example, purely electrically operated, so that the emotionally evoking combustion noises are eliminated. The motor vehicle is, for example, a BEV or an FCEV [Fuel Cell Electric Vehicle] or a hybrid vehicle in which the combustion engine is not suitable for generating such emotionally evoking noise emissions due to its design, e.g. displacement, and / or its time-limited use (i.e., interrupted, e.g., depending on the battery charge level). The noise simulator is attached to the motor vehicle (preferably externally) and the sound outlet is directed towards the surroundings of the motor vehicle.This allows for the creation of an emotional sound for pedestrians or spectators, as well as for the driver in the vehicle's cab, similar to the noise of a combustion engine, for example. At the same time, the legal requirements for pedestrian warning systems are met, and pedestrians are warned of an approaching motor vehicle in the usual way using this sound simulator. The sound simulator thus implicitly fulfills the functions of an AVAS, which therefore does not need to be provided as a separate, supplementary system.

[0031] It is further proposed in an advantageous embodiment of the motor vehicle that the noise simulator is arranged at the rear of the motor vehicle, preferably instead of a tailpipe of an exhaust system.

[0032] Here, it is proposed that the noise simulator be arranged at the rear of the motor vehicle, preferably fastened to the chassis of the motor vehicle. The location of the noise simulation using the noise simulator is therefore very similar to the conventional location of noise generation in a motor vehicle with an internal combustion engine. The noise simulator is preferably arranged instead of a tailpipe of an exhaust system, in comparison to a conventional motor vehicle in which an internal combustion engine represents the (permanently used) main drive. If the motor vehicle comprises an exhaust system (and an internal combustion engine), this conventional exhaust system is preferably placed elsewhere, for example in the central region (in the direction of travel) on the underbody of the motor vehicle, preferably with the tailpipe directed towards the ground.

[0033] The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way limited by the purely schematic drawings, whereby it should be noted that the drawings are not to scale and are not suitable for defining proportions. It is shown in Fig. 1: a sound simulator with a straight pipe; Fig. 2: a noise simulator with a bent pipe; Fig. 3: a sound simulator with a loudspeaker; Fig. 4: a noise simulator with a loudspeaker and two structure-borne sound transducers; Fig. 5: a noise simulator with a multi-pipe; Fig. 6: a diagram of a frequency dependence of a sound pressure curve; and Fig. 7: a noise simulator at the rear of a motor vehicle.

[0034] In Fig. 1 shows a schematic sectional view of a noise simulator 1 with a straight tube 10. In this embodiment, the noise simulator 1 has a loudspeaker 12, the loudspeaker membrane 17 of which is in direct contact with the environment 9, and the (here optionally only) noise source 5 is formed by its magnet 18 (for the voice coil, not shown) in the interior space 4 enclosed by the housing 3. For example, the housing 3, i.e., the box-shaped wall here, is made entirely of titanium. As shown, a tube 10 is arranged below the loudspeaker 12 (purely optional), projecting vertically into the housing 3, the (here optionally only) sound outlet 6 being formed by the (output) opening of the tube 10 facing the environment 9. When the loudspeaker 12 is actively vibrated, the loudspeaker 12 emits sound waves 19 into the environment 9 via the loudspeaker membrane 17.In addition, the loudspeaker 12 also emits sound waves 20 backwards into the interior space 4. For the sound waves 20 to the interior space 4, the housing 3 forms the resonance body, and these are discharged (airborne) into the environment 9 solely through the inlet opening 38 of the tube 10 and through the sound outlet 6 (here of the tube 10), thereby amplified the sound waves 20 conducted through the interior space 4 (cf. Fig. 6). The geometry of the interior space 4 and the position of the tube 10 determine the path and thus the timbre and volume level of the sound waves 20 in the interior space 4.

[0035] In Fig. Figure 2 shows a schematic sectional view of a noise simulator 1 with a bent tube 10. In this embodiment, the noise source 5 comprises a loudspeaker 12, for example according to Fig. 1, and a structure-borne sound transducer 13. The housing 3, for example made entirely of titanium, encloses an interior space 4 which is separated by a partition wall 21, for example also made of titanium, thus forming a first chamber 22 and a second chamber 23. The loudspeaker 12 is arranged in the first chamber 22, and the structure-borne sound transducer 13 is arranged directly on the mounted housing 3 in the second chamber 23. Here, the tube 10, which amplifies the low-frequency sound waves of the loudspeaker 12, is arranged such that the sound outlet 6 to the environment 9 is arranged in the second chamber 23, and the tube 10 projects via a 90° bend 11 in the second chamber 23 through the partition wall 21 into the first chamber 22 and has the inlet opening 38 in this chamber 22.

[0036] In Fig. 3 shows a noise simulator 1 with a (single) loudspeaker 12. For the structure and operation of the noise simulator 1, please refer to the previous description. Fig. 1. In this embodiment, the housing 3 comprises an upper half-shell 7, a lower half-shell 8, and a sound outlet element 24, wherein the upper half-shell 7, the lower half-shell 8, and / or the sound outlet element 24 are made of titanium and designed in the form of a conventional silencer of a conventional exhaust system. Here, the loudspeaker 12 is embedded in the upper half-shell 7, and the loudspeaker membrane 17 is in direct contact with the environment 9. Here, the sound outlet 6 of the pipe 10 is formed in the form of a tailpipe of a conventional exhaust system in a sound outlet element 24, and the pipe 10 leads, for example, as in Fig. 1, from the housing 3 to the sound outlet 6.

[0037] In Fig. 4 shows a noise simulator 1 with a loudspeaker 12 and two structure-borne sound transducers 13. Refer to the previous description. Fig. 3 and only the differences in the design are discussed. Therefore, there are two additional structure-borne sound transducers 13 in the interior 4 (compare Fig. 2) on the upper half-shell 7 in addition to the loudspeaker 12 embedded in the upper half-shell 7. The tube 10 is preferably closed by the interior space 4 (see Fig. 1 and Fig. 2) and the structure-borne sound transducers 13 are arranged at a distance therefrom in the interior space 4.

[0038] In Fig. 5 shows a noise simulator 1 with a multiple pipe. For the structure and operation of the noise simulator 1, please refer to the previous description. Fig. 1. In this embodiment, a multiple pipe in the form of a manifold pipe 14 is provided in the housing 3, and at least some of the sound waves are guided through the manifold pipe 14 to the sound outlet 6. For this purpose, the manifold pipe 14 comprises a first sub-pipe 25, a second sub-pipe 26, and a third sub-pipe 27, which end in a common sound outlet 6. For this purpose, a loudspeaker 12, preferably its respective magnetic coil (with the loudspeaker diaphragm 17 directed outside the housing 3, i.e., toward the environment 9), is each assigned to the first sub-pipe 25, the second sub-pipe 26, and the third sub-pipe 27, so that the inlet opening 38 (not shown here) of the first sub-pipe 25, the second sub-pipe 26, and the third sub-pipe 27, arranged in the interior space 4, is close to the loudspeaker 12 or directly connected to the loudspeaker 12.

[0039] In Fig. Figure 6 is a graphical representation of the intensity or level (L) of a noise simulator 1, for example according to Fig. 3, in different frequency ranges. The frequency (f) is plotted on an abscissa 28. The loudness or level (L) is plotted on an ordinate 29. Curve 30 shows the course of a measured noise as it is generated by the noise simulator 1 according to Fig. 3 was measured in the environment 9. Furthermore, the frequency range can be divided into a low frequency range 31 and a medium frequency range 32. Here it is shown that in the low frequency range 31 by using a tube 10, such as in Fig. 3, the level (L) of the low frequencies is increased. In the mid-frequency range 32, the geometry of the housing 3, the housing material (e.g., titanium), and the use of structure-borne sound transducers 13 are crucial for the level (L). Thus, various parameters exist for adapting the noise simulator 1 to the desired requirements.

[0040] In Fig. 7 shows a motor vehicle 2 in a schematic side view. In the area of ​​the rear 16, a drive motor 15, for example an electric drive motor 15, is arranged, which is connected in a torque-transmitting manner to at least the wheels 34 located on the rear wheel axle 33 for propelling the motor vehicle 2. In the front area of ​​the motor vehicle 2 and in front of the driver's cab 35, the front wheels 36 are arranged on the common front wheel axle 37 and serve, for example, to steer the motor vehicle 2. Here, the noise simulator 1 is shown, for example, according to an embodiment from Fig. 3 to Fig.5 is arranged at the rear 16 of the motor vehicle 2. The sound outlet 6 of the noise simulator 1 is directed toward the environment 9, similar to a conventional tailpipe of an exhaust system, and the sounds generated by the noise simulator 1 are perceptible in the usual emotional manner to passersby as well as to the driver in the driver's cab 35 of the motor vehicle 2.

[0041] With the noise simulator proposed here, authentic drive noises for the vehicle's surroundings can be generated. List of reference symbols 1 sound simulator 2 motor vehicles 3 housings 4 Interior 5 Noise source 6 Sound outlet 7 upper half shell 8 lower half shell 9 Surroundings 10 pipe 11 Bend 12 speakers 13 structure-borne sound transducers 14 Manifold pipe 15 drive machine 16 Rear 17 Loudspeaker membrane 18 Magnet 19 sound waves to the environment 20 sound waves to the interior 21 Partition wall 22 first chamber 23 Second Chamber 24 Sound outlet element 25 first part of the pipe 26 second part of the pipe 27 third part of the pipe 28 Abscissa 29 Ordinates 30 curve 31 low frequency range 32 mid-frequency range 33 rear wheel axle 34 rear wheel 35 Driver's cab 36 front wheel 37 front wheel axle 38 Entrance opening

Claims

[1] Noise simulator (1) for a motor vehicle (2), comprising at least the following components: - a housing (3) which encloses an interior space (4); - at least one electrically controllable noise source (5) arranged in the interior (4) of the housing (3), wherein at least one of the noise sources (5) is a loudspeaker (12) which is arranged such that the sound-emitting membrane (17) is directed outside the housing (3), i.e. directly towards the environment (9), and the basket of the loudspeaker (12) is fastened to the housing (3) such that the magnet (18) is arranged at least partially in the interior (4) of the housing (3); and - a sound outlet (6) in the housing (3), wherein the housing (3) is designed as a resonance body for at least one of the noise sources (5), wherein the housing (3) comprises a material for tailpipes of an exhaust system, wherein the sound outlet (6) is connected to a pipe (10) arranged in the interior (4) of the housing (3), and wherein the pipe (10) has a bend (11). [2] Noise simulator (1) according to claim 1, wherein the material of the housing (3) comprises titanium. [3] Noise simulator (1) according to claim 2, wherein the housing (3) comprises two half-shells (7,8). [4] Noise simulator (1) according to one of claims 1 to 3, wherein in use the sound outlet (6) is directed towards the environment (9) of a motor vehicle (2). [5] Noise simulator (1) according to one of the preceding claims, wherein the bend (11) is guided by 90°. [6] Noise simulator (1) according to one of the preceding claims, wherein the noise source (5) further comprises at least one of the following components: - a structure-borne sound transducer (13); and - a manifold pipe (14) designed as a single pipe or as a multiple pipe. [7] Motor vehicle (2), comprising a drive engine (15) for propelling the motor vehicle (2), and a noise simulator (1) according to one of the preceding claims for generating ambient noise. [8] Motor vehicle (2) according to claim 7, wherein the noise simulator (1) is arranged at the rear (16) of the motor vehicle (2). [9] Motor vehicle (2) according to claim 7 or 8, wherein the noise simulator (1) is arranged at the rear (16) of the motor vehicle (2) instead of a tailpipe of an exhaust system.

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