AVAS noise generator for a hybrid vehicle

Abstract

Noise generator (20) for a hybrid vehicle (10), which comprises a loudspeaker and provides a resonator volume (22) for the loudspeaker (21) and which has a connection (24) fluidly connected to the resonator volume (22) for connecting a secondary air pump (31) of a secondary air system (30) of a hybrid vehicle (10).

Description

[0001] The invention relates to a noise generator for a hybrid vehicle, which comprises a loudspeaker and provides a resonator volume for the loudspeaker. Furthermore, the invention relates to a hybrid vehicle, a method for operating a noise generator, and a use of a noise generator.

[0002] Hybrid vehicles comprise both an internal combustion engine and an electric motor and can therefore be powered purely by an internal combustion engine, purely by an electric motor or hybrid, i.e. by both an internal combustion engine and an electric motor.

[0003] In addition, a hybrid vehicle typically includes an exhaust system connected to the internal combustion engine and a secondary air system connected to the exhaust system, which includes a secondary air pump (SLP) for drawing in ambient air. However, the secondary air pump generates sound waves that are perceived as disturbing in the interior of the hybrid vehicle. To reduce disturbing noises in the interior, the secondary air system includes a secondary air resonator, also known as a sound transducer, connected to the secondary air system.

[0004] DE 100 15 697 C1 discloses such a sound transducer for a motor vehicle, which is connected to the exhaust system of the motor vehicle and comprises a modulation element, a valve, and a sound head with a resonator volume. The sound head is arranged at a distance from the combustion engine and therefore does not need to have high temperature resistance.

[0005] DE 102 59 099 A1 discloses another sound transducer for a motor vehicle. The sound transducer can be connected to the motor vehicle's exhaust system on the input side and defines a resonator volume delimited by a membrane on the output side. The sound transducer modulates an incoming sound from the exhaust system into an outgoing sound, which is perceived as less disturbing in the interior of the motor vehicle. In contrast, DE 102 26 205 B4 discloses a device for actively influencing sound using a loudspeaker arranged in the intake tract of an internal combustion engine. WO 2018 / 234 212 A1 describes a loudspeaker that, thanks to a variable resonator volume, generates an optimal sound pressure either at high or low frequencies.

[0006] While the secondary air system, especially the secondary air pump, represents an undesirable noise source, a vehicle may also contain useful noise sources.

[0007] For example, DE 10 2008 040 139 A1 discloses a noise generator for a vehicle comprising a drive unit and a continuously variable transmission. The noise generator is configured to simulate the operating noise of the drive unit independently of the drive unit's speed in order to provide a driver of the vehicle with the acoustic driving experience of a stepped transmission.

[0008] Suitable sound sources for an electric vehicle, i.e., a vehicle with an electric drive unit, or an electric motor for short, also include a so-called acoustic vehicle alerting system (AVAS). The acoustic vehicle alerting system comprises a noise generator that, by means of a loudspeaker and a resonator volume, generates a clearly audible noise in the vicinity of the electric vehicle when the electric vehicle is running purely on electric power, in order to alert people in the vicinity to the moving electric vehicle. DE 10 2011 116 635 A1, on the other hand, describes a warning system for a vehicle with an internal combustion engine. The warning system comprises a loudspeaker arranged in a rear muffler of the vehicle's exhaust system.

[0009] However, the AVAS sound generator is only active during non-combustion-engine driving at low speeds, for example, during slow, purely electric-powered driving of the hybrid vehicle or during slow, completely non-powered driving of the hybrid vehicle, i.e., during coasting or regenerative braking. Accordingly, the AVAS sound generator has a relatively short overall operating time during an electric vehicle's journey.

[0010] The invention is therefore based on the object of providing an improved noise generator for a hybrid vehicle that has a longer service life during a journey of the hybrid vehicle. Furthermore, the invention proposes a hybrid vehicle, a method for operating a noise generator of a hybrid vehicle, and a use of a noise generator.

[0011] One subject of the present invention is a noise generator for a hybrid vehicle, which comprises a loudspeaker and provides a resonator volume for the loudspeaker. The noise generator can be designed as an AVAS (Acoustic Vehicle Alerting System) noise generator, which can be mounted in a hybrid vehicle.

[0012] The noise generator according to the invention has a connection for connecting a secondary air pump (SLP) of a secondary air system of a hybrid vehicle. The connection is fluidly connected to the resonator volume. By means of the connection, the resonator volume of the noise generator can be connected to the secondary air system, in particular the secondary air pump. Accordingly, the resonator volume of the noise generator can act as a secondary air resonator, thereby eliminating the need for a separate secondary air generator. This reduces the complexity and costs of the hybrid vehicle, and saves the installation space required for the omitted secondary air resonator.

[0013] In a preferred embodiment, the sound generator comprises a housing defining the resonator volume, to which the loudspeaker is attached. Briefly, the loudspeaker is arranged at an opening in the housing so that a vibrating element of the loudspeaker, usually a membrane, can vibrate between an external environment and the resonator volume inside the housing.

[0014] In advantageous embodiments, the housing comprises or consists of a material that is heat-resistant at least up to a maximum operating temperature of an electric motor and / or an internal combustion engine and / or an exhaust system of the hybrid vehicle. Thanks to the heat resistance of the material, the noise generator can be arranged adjacent to the electric motor, the internal combustion engine, or the exhaust system, thus ensuring high flexibility when mounting the noise generator in the hybrid vehicle.

[0015] The invention also relates to a hybrid vehicle comprising a noise generator according to the invention and a secondary air pump of a secondary air system of the hybrid vehicle, which is connected to the connection of the noise generator. The hybrid vehicle offers additional installation space with reduced complexity and reduced costs.

[0016] Furthermore, the invention relates to a method for operating a noise generator for a hybrid vehicle, in which, during non-combustion engine operation of a hybrid vehicle, a resonator volume of a noise generator of the hybrid vehicle is utilized by a loudspeaker of the noise generator. This corresponds to the original or primary operating mode of the resonator volume of the noise generator.

[0017] In the method according to the invention, the resonator volume of the noise generator is utilized by a secondary air pump of a secondary air system of the hybrid vehicle during a combustion engine-driven drive of the hybrid vehicle. This is an additional or secondary operating mode of the resonator volume of the noise generator, thereby achieving an overall longer service life of the resonator volume during a drive of the hybrid vehicle.

[0018] In a preferred embodiment, the resonator volume of the noise generator is used exclusively by the loudspeaker during non-combustion-engine-powered driving of the hybrid vehicle when the driving speed of the hybrid vehicle is lower than a predetermined limit speed. Hybrid vehicles traveling slowly without an internal combustion engine are particularly easy to miss. Uninterrupted operation of the noise generator during such phases of hybrid vehicle driving particularly effectively reduces the danger posed by the hybrid vehicle.

[0019] In a further preferred embodiment, the resonator volume is used exclusively by the secondary air pump during a drive of the hybrid vehicle with the internal combustion engine. In other words, the resonator volume is used in a secondary operating mode during a phase of a drive in which it would be unused in the original operating mode of the noise generator.

[0020] Particularly preferably, a noise generator according to the invention is operated in the method. The method is thus based on a noise generator with a connection to which a secondary air system, in particular a secondary air pump of a hybrid vehicle, can be connected.

[0021] Furthermore, the invention relates to the use of a resonator volume of a noise generator of a hybrid vehicle as a resonator volume for a secondary air pump of a secondary air system of the hybrid vehicle. The noise generator thus enjoys dual use, thereby achieving a longer service life of the resonator volume of the noise generator during a drive of the hybrid vehicle.

[0022] Preferably, a noise generator according to the invention is used. The noise generator according to the invention is configured for dual use.

[0023] A key advantage of the noise generator is the reduced volume required for sound resonance in a hybrid vehicle. This reduced volume requirement is achieved through a higher degree of component integration, i.e., the dual use of a resonator volume of a noise generator. This is accompanied by reduced complexity, reduced costs, reduced installation space requirements, and reduced weight of the hybrid vehicle. The saved installation space can be used for other components of the hybrid vehicle.

[0024] The invention is illustrated schematically in the drawings using embodiments and will be further described with reference to the drawings. It shows: Fig. 1 is a schematic representation of a partial plan view of a hybrid vehicle according to the prior art; Fig. 2 is a schematic representation of a partial plan view of a hybrid vehicle according to an embodiment of the invention; Fig. 3 in a function graph operating states of the Fig. 2 shown hybrid vehicle and types of use of the Fig. 2 shown noise generator.

[0025] Fig. Figure 1 shows a schematic representation of a partial top view of a hybrid vehicle 1 according to the prior art. The hybrid vehicle 1 comprises an internal combustion engine 11, an exhaust system 12 connected to the internal combustion engine, an electric motor (not shown), and a vehicle interior 13, i.e., a passenger compartment.

[0026] Furthermore, the hybrid vehicle 1 comprises a secondary air system 30 with a secondary air pump (SLP) 31, a secondary air resonator 32 and an air filter 33. The secondary air system 30 is connected to the exhaust system 12.

[0027] The hybrid vehicle 1 also includes a noise generator, which is embodied, for example, as an AVAS (Acoustic Vehicle Alerting System) noise generator 20 of an acoustic vehicle warning system. The AVAS noise generator 20 comprises a housing 23 and a loudspeaker 21 attached to the housing. The housing 23 defines a resonator volume 22 for the loudspeaker 21.

[0028] During purely electric-powered travel of the hybrid vehicle 1, the resonator volume 22 of the AVAS sound generator 20 is activated when the loudspeaker 21 of the AVAS sound generator 20 generates acoustic sound waves to simulate engine noise. During combustion-engined travel of the hybrid vehicle 1, the secondary air system 30 supplies ambient air to the exhaust system 12 as so-called secondary air, with the secondary air pump 31 drawing in the ambient air through the air filter 33. A resonator volume of the secondary air resonator 32 modulates acoustic sound waves generated by the secondary air pump 31 to reduce disruptive noises of the secondary air system 30, particularly in the vehicle interior 13.

[0029] Fig. 2 shows a schematic representation of a partial plan view of a hybrid vehicle 10 according to an embodiment of the invention. The hybrid vehicle 10 has the same basic structure as the hybrid vehicle 1 according to the prior art. Unlike the prior art, it does not include a secondary air resonator. Instead, the AVAS noise generator 20 has a connection 24 for connecting the secondary air system 30, more precisely the secondary air pump 31 of the secondary air system 30, which connection is formed on the housing 23 and is fluidly connected to the resonator volume 22 of the AVAS noise generator 20. The AVAS noise generator 20 is connected to the exhaust system 12 by means of the connection 24. In this way, the AVAS noise generator 20 acts like a secondary air resonator, i.e., the resonator volume 22 of the AVAS noise generator 20 replaces the resonator volume of the secondary air resonator 32 according to the prior art.In other words, according to the invention, the resonator volume 22 of the AVAS noise generator 20 is used as a resonator volume 22 for the secondary air system 30, more specifically for the secondary air pump 31. The resonator volume 22 of the AVAS noise generator 20 thus has a dual purpose.

[0030] Ideally, the housing 23 comprises or is made of a material that is heat-resistant at least up to a maximum operating temperature of the electric motor, the internal combustion engine 11, or the exhaust system 12 of the hybrid vehicle 10. If the housing 23 is designed in this way, it can also be arranged adjacent to the electric motor, the internal combustion engine 11, or the exhaust system 12 in the hybrid vehicle 10.

[0031] During a purely electric-motor drive of the hybrid vehicle 10, the resonator volume 22 of the AVAS noise generator 20 of the hybrid vehicle 10 is used by the loudspeaker 21 of the noise generator 20. The resonator volume 22 is used exclusively by the loudspeaker 21 when a driving speed of the hybrid vehicle 10 is lower than a predetermined limit speed 61, see Fig. 3.

[0032] During a combustion engine drive of the hybrid vehicle 10, the resonator volume 22 of the AVAS noise generator 20 is used by the secondary air pump 31 of the secondary air system 30 of the hybrid vehicle 10. In particular, during a hybrid drive of the hybrid vehicle 10, the resonator volume 22 is used exclusively by the secondary air pump 31 if a driving speed of the hybrid vehicle 10 is greater than the predetermined limit speed 61, see Fig. 3.

[0033] Fig. 3 shows in a function graph 40 operating states of the Fig. 2 shown hybrid vehicle and types of use of the Fig. 2. The function graph 40 comprises six separate coordinate systems, each with an ordinate 60 and an abscissa 50, on which the travel time t is plotted. The abscissas 50 are scaled and the coordinate systems are arranged one above the other in such a way that identical points in time lie on a straight line parallel to the ordinates 60 of the coordinate systems.

[0034] A driving speed 62 is plotted on the ordinate 60 of the first - uppermost - coordinate system. In addition, the limit speed 61 is entered in the first coordinate system as a constant in the form of a ray parallel to the abscissa 50.

[0035] An operating state 63 of the electric motor is plotted on the ordinate 60 of the second coordinate system, which here only distinguishes between an on state and an off state of the electric motor.

[0036] An operating state 64 of the internal combustion engine 11 is plotted on the ordinate 60 of the third coordinate system, which here only distinguishes between a switched-on state and a switched-off state of the internal combustion engine 11.

[0037] An operating state 65 of the loudspeaker 21 of the AVAS noise generator 20 is plotted on the ordinate 60 of the fourth coordinate system, which operating state here only distinguishes between an on state and an off state of the AVAS noise generator 20.

[0038] An operating state 66 of the secondary air pump 31 is plotted on the ordinate 60 of the fifth coordinate system, which here only distinguishes between an on state and a off state of the secondary air pump 31.

[0039] The operating states 65, 66 of the loudspeaker 21 and the secondary air pump 31 are plotted together on the ordinate 60 of the sixth—lowest—coordinate system. The sixth coordinate system shows that the operating states 65, 66 of the loudspeaker 21 and the secondary air pump 31 are either opposite or simultaneously equal to the off state. It is clear that the resonator volume 22 of the AVAS noise generator 20 is used exclusively by the loudspeaker 21 or the secondary air pump 31, i.e., at no time is it used jointly by the loudspeaker 21 and the secondary air pump 31.

[0040] In a first phase, designated I, the hybrid vehicle 10 is driven purely by the electric motor at a driving speed below the limit speed 62. Phase I begins with the switch-on times 51, 55 of the electric motor and the loudspeaker 21 of the AVAS noise simulator, respectively. Phase I ends with the switch-on time 53 of the combustion engine 11 and the switch-off time 52 of the electric motor. Since the purely electric motor drive ends with the switch-on of the combustion engine 11, the switch-on time 53 of the combustion engine also coincides with the switch-off time 56 of the loudspeaker 21. Naturally, the switch-on time 57 of the secondary air pump 31 coincides with the switch-on time 53 of the combustion engine 11.

[0041] Phase I is followed by a short second phase, designated II, in which the hybrid vehicle 10 is driven purely by the combustion engine at a driving speed below the speed limit 62. The secondary air pump 31 is switched on in phase II, while the loudspeaker 21 is switched off.

[0042] Phase II is followed by a third phase, designated III, which begins with a switch-on time 51 of the electric motor and in which the hybrid vehicle 10 is driven hybridly (i.e., simultaneously by the electric motor and the combustion engine) at a significantly increasing driving speed above the limit speed 62 (boost). Phase III therefore features neither a driving speed below the limit speed 62 nor a purely electric motor drive. Therefore, the loudspeaker 21 remains switched off in Phase III, while the secondary air pump 31 remains switched on.

[0043] Phase III is followed by a relatively long fourth phase, designated IV, which begins with a switch-off point 52 of the electric motor and in which the hybrid vehicle 10 is again driven purely by the combustion engine above the limit speed 62. In phase IV, the secondary air pump 31 is switched on, while the loudspeaker 21 remains switched off.

[0044] Phase IV is followed by a fifth phase, designated V, which begins with a switch-off point 54 of the combustion engine 11 and in which the hybrid vehicle 10 is decelerated without propulsion above the limit speed 62. In phase V, the loudspeaker 21 and the secondary air pump 31 are switched off simultaneously.

[0045] Phase V is followed by a sixth phase, designated VI, which begins with a switch-on time 55 of the loudspeaker 21 and in which the hybrid vehicle 10 continues to decelerate without propulsion below the limit speed 62. In phase VI, the secondary air pump 31 is switched off. Phase VI, and thus the travel of the hybrid vehicle 10, ends with a switch-off time 56 of the loudspeaker 21.

[0046] The above driving profile serves merely as a simple example to illustrate the mutually exclusive use of the resonator volume 22 of the AVAS noise generator 20 by the loudspeaker 21 and the secondary air pump 31. Of course, the present invention relates to any possible driving profile, ie, any possible sequence and duration of phases, of the hybrid vehicle 10. LIST OF REFERENCE SYMBOLS: 1 hybrid vehicle (state of the art) 10 hybrid vehicles 11 Internal combustion engine 12 Exhaust system 13 Vehicle interior 20 noise generator 21 speakers 22 resonator volume 23 housings 24 connection 30 Secondary air system 31 Secondary air pump 32 Secondary air resonator 33 air filters 40 Function graph 50 Abscissa 51 Switch-on time of electric motor 52 Switch-off time of electric motor 53 Switch-on time of combustion engine 54 Switch-off time of combustion engine 55 Speaker switch-on time 56 Speaker switch-off time 57 Switch-on time of secondary air pump 58 Switch-off time of secondary air pump 60 ordinates 61 speed limit 62 driving speed 63 Operating state of the electric motor 64 Operating state of the combustion engine 65 Operating status of the AVAS noise generator loudspeaker 66 Operating status of the secondary air pump

Claims

[1] Noise generator (20) for a hybrid vehicle (10), which comprises a loudspeaker and provides a resonator volume (22) for the loudspeaker (21) and which has a connection (24) fluidly connected to the resonator volume (22) for connecting a secondary air pump (31) of a secondary air system (30) of a hybrid vehicle (10). [2] A noise generator according to claim 1, which comprises a housing (23) defining the resonator volume (22) to which the loudspeaker (21) is attached. [3] Noise generator according to claim 2, wherein the housing (23) comprises or consists of a material which is heat-resistant at least up to a maximum operating temperature of an electric motor and / or an internal combustion engine (11) and / or an exhaust system (12) of the hybrid vehicle (10). [4] Hybrid vehicle (10), comprising a noise generator (20) according to one of claims 1 to 3 and a secondary air pump (31) of a secondary air system (30) of the hybrid vehicle (10), which is connected to the connection (24) of the noise generator (20). [5] Method for operating a noise generator (20) for a hybrid vehicle (10), in which during a non-combustion engine drive of a hybrid vehicle (10) a resonator volume (22) of the noise generator (20) of the hybrid vehicle (10) is used by a loudspeaker (21) of the noise generator (20) and in which during a combustion engine drive of the hybrid vehicle (10) the resonator volume (22) of the noise generator (20) is used by a secondary air pump (31) of a secondary air system (30) of the hybrid vehicle (10) connected to a connection (24) of the noise generator (20) that is fluidly connected to the resonator volume (22). [6] Method according to claim 5, wherein the resonator volume (22) of the noise generator (20) is used exclusively by the loudspeaker (21) during non-combustion engine travel of the hybrid vehicle (10) when a travel speed (62) of the hybrid vehicle (10) is lower than a predetermined limit speed (61). [7] Method according to claim 6, wherein the resonator volume (22) is used exclusively by the secondary air pump (31) during the internal combustion engine drive of the hybrid vehicle (10). [8] Method according to one of claims 6 or 7, in which a noise generator (20) is operated according to one of claims 1 to 3. [9] Use of a resonator volume (22) of a noise generator (20) of a hybrid vehicle (10) as a resonator volume (22) for a secondary air pump (31) of a secondary air system (30) of the hybrid vehicle (10) connected to a connection (24) of the noise generator (20) fluidly connected to the resonator volume (22). [10] Use according to claim 9, wherein a noise generator (20) according to one of claims 1 to 3 is used.

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