DE10149169C1 - Acoustic modulator head for fitting to a motor vehicle's internal combustion engine has an inlet opening for a feeder line, a membrane, an acoustic dispersing area and an airtight separator panel dividing a casing into two sections. - Google Patents

Abstract

The invention relates to an acoustic transducer head (4), comprising at least one admission opening (5) for an inlet line, at least one first pulsation converting member (13) and at least one acoustic radiation zone (9) in a housing (3). According to said invention, a substantially airproof partition (7) divides said housing (3) into at least two sections, a first section being functionally linked to the admission opening (5) and the second section to the acoustic radiation zone. Said first pulsation converting member (13) is arranged in the first section, which is divided into a first chamber (15) and a second chamber (17). A pressure compensation device (19) is arranged between the first chamber (15) and the second chamber (17). A second pulsation converting member is arranged at least partially in said second section, such that at least one member part can move and a transmitting device (25) is arranged between the first and second sections for transmitting oscillations of the first pulsation converting member (13) to the second pulsation converting member (31). Said invention also relates to an acoustic transducer, provided with said head, as well as to a method for acoustic transduction.

Description

The present invention relates to a transducer head, with at least one inlet opening tion for a supply line, at least a first membrane and at least one sound radiation area in a housing, and a sound transducer in an exhaust gas and / or  Intake area of an internal combustion engine, in particular a motor vehicle, with such an egg transducer head.

For example from DE 199 22 216 A1 a generic transducer head is known as Part of a sound transmission device for a motor vehicle known. Through the scarf Oil transmission device is achieved that a targeted sound transmission from one type suction tract of an internal combustion engine of a motor vehicle to an interior of the motor vehicle stuff is reached. To achieve an improvement in the sound radiation performance, the Use of a transmission body proposed, which comprises a λ / 2 resonator. before the output side of this λ / 2 resonator is sealed with a membrane.

Furthermore, the applicant's unpublished DE 100 15 697 describes a sound transducer described for exhaust gas pulsations. This sound converter is the exhaust system of a burner Engine, in particular a motor vehicle, assigned and includes a genus appropriate transducer head, via which airborne sound is emitted based on the exhaust gas pulsations can be radiated at least into the space of the internal combustion engine. This transducer head can have different geometries and includes a membrane.

A disadvantage of the generic transducer heads, however, is that at high static Air pressures within the transducer head cause the diaphragm to tense and thus sound radiation can be hindered.

Double-membrane systems are known for condenser microphones, see DE 197 15 365 A1. A corresponding condenser microphone comprises a first membrane which a counter electrode is coupled for sensing vibrations of the first membrane, and a second membrane above the first membrane, which provides effective protection against the penetration of sweat into the microphone. A disadvantage of this condenser microphone, however, is that the distance between the two membranes must be kept very small in order to have a sufficient transmission effect from the second to achieve the first membrane.

The object of the present invention is therefore the generic transducer head to develop in such a way that the disadvantages of the prior art are overcome, This enables optimized sound radiation, particularly in the largest possible pressure ranges light becomes.

This object is achieved in that an essentially airtight Partition, by means of which the housing is divided into at least two sections, the first section with the inlet opening and the second section with the outlet opening in Operatively connected, the first membrane is arranged in the first section and densel ben divided into a first and a second chamber, a pressure compensation device between between the first and the second chamber, a pulsation conversion element that at least is partially movable in the second section at least in regions, and a transmission device between the first and second sections for transmission of vibrations of the first membrane on the pulsation conversion element.

It can be provided that the pressure compensation device has at least one connection opening in the first membrane, in one with the first membrane and the transfer supply device in operative connection and / or between the comprises the first membrane and the housing and / or a bypass.

It is further proposed that the pressure compensation device be at least one, preferred as adjustable in its damping properties, damping element, in particular in Form of a variable cross-sectional reduction, a labyrinth and / or a porous Materials such as foam, iron wool and / or the like.

According to the invention it is also proposed that the geometric dimensions of the first Section, in particular the first and / or second chamber, the inlet opening, the zu guide line and / or the second section, in particular the sound radiation area, is or can be changed, preferably during operation of the transducer head.  

It is provided that the sound radiation area is essentially horn-shaped.

It is further provided according to the invention that the pulsation conversion element has at least one second membrane, which divides the second section into a third and fourth chamber, and / or at least one structure-borne noise generator, in particular comprising a plunger, for mechanical excitation of an at least partially arranged in the sound radiation area th body, in particular comprised by the housing.

The invention is also characterized in that the transmission device at least a, in particular rigid, mechanical, electromechanical and / or magnetomechanical Coupling element and / or at least one positioning device.

It can be provided that at least one sealing device, preferably in the form a Simerring, for storage and implementation of the coupling element.

In the aforementioned alternatives, the electromechanical coupling can be used according to the invention element at least one, preferably electromagnetic, scanning device for scanning the vibrations of the first membrane and a, preferably electromagnetic, drive include means for driving the pulsation converter.

It is further proposed that the positioning device in at least one spring element the first, second, third and / or fourth chamber and / or during an operation bes of the transducer head is controllable and / or adjustable.

The present invention is advantageously characterized in that a control and / or regulating device for controlling and / or regulating the sound radiation characteristics, especially in operative connection with the partition, the first membrane, the damping element, the pulsation converter, a signal generator for at least one other External signal and / or transmission influencing sound radiation characteristics Facility.  

It can be provided according to the invention that the first and / or second membrane Elastomer, a reinforcing fabric, a plastic and / or a sheet metal or comprises sen.

Furthermore, it can also be provided that the first and / or second membrane are different Membrane thicknesses, different flexibility and / or different shapes or have, preferably for providing a stiffer central region and a fle more flexible edge area.

Finally, it is also proposed that the bias of the first and / or second Membrane and / or the size of at least one vibratory area of the first and / or second membrane, in particular during operation of the transducer head, is or can be controlled and / or regulated.

The invention also provides a sound transducer in an exhaust gas and / or intake area an internal combustion engine, in particular a motor vehicle, with a transducer head according to one of the preceding claims.

The invention is therefore based on the surprising finding that a transducer head can be carried out such that, on the one hand, exhaust gas pulsations of an internal combustion engine in particular machine of a motor vehicle in vibration in a substantially closed Space to be converted and on the other hand, a functionality even for example static pressure from 0.5 to 1 bar is ensured by an excitation membrane either with a sound radiation membrane or a structure-borne noise generator under pressure compensation is coupled.

Further features and advantages of the invention result from the description below Exercise, in the preferred embodiments of the invention by way of example using schematic Drawings are explained. It shows:  

Figure 1 is a sectional view of a first embodiment of the transducer head according to the invention.

Fig. 2 is a sectional view of a second embodiment of the transducer head of the invention;

Fig. 3 is a sectional view of a third embodiment of the transducer head of the invention; and

Fig. 4 is a sectional view of a fourth embodiment of the transducer head according to the invention.

In Fig. 1, a first transducer head 1 according to the invention with a housing 3 is Darge that has an inlet opening 5 which is connected to a supply line, not shown, for supplying pulsations, in particular intake and / or exhaust gas pulsations of an internal combustion engine of a motor vehicle. Within the housing 3 , a partition 7 is arranged, which divides the interior of the transducer head 1 into a opening 5 facing the inlet opening 5 and a sound radiation region 9 facing second section. In order to achieve improved sound radiation of the sound transducer head 1 , the housing 3 is designed in the sound radiation area 9 in the form of a horn 11 . In the inlet section 5 facing the first section of the transducer head 1 , an excitation membrane 13 is arranged, which in turn cuts the first section into two chambers 15 and 17 , separated from each other in an airtight manner. However, the transducer head 1 has a connecting tube 19 which connects the chambers 15 and 17 so that there is always a static pressure equalization between these two chambers. For this purpose, the connecting pipe 19 also includes a damping element 21 , for example in the form of an adjustable cross-sectional constriction of the connecting pipe 19 , by which it is ensured that high-frequency pressure fluctuations due to pulsations supplied to the transducer head 1 via the inlet opening 5 are not transmitted via the connecting pipe 19 . The excitation membrane 13 is in its central region via a connecting member, namely in the form of a center plate 23, having a rigid coupling rod 25 in operative connection. This coupling rod 25 is via a sealing device in the form of a Simerrings 27 through the partition wall 7 ge frictionless to ensure an airtight separation of the first section from the second section si cher. The second section is also divided into two chambers 29 and 33 by a sound radiation membrane 31 . The sound radiation membrane 31 , like the excitation membrane 13 , has a center plate 35 which is connected to the coupling rod 25 . The two membranes 13 and 31 are held in position in the form of Fe derelemente 37 and 39 in a predetermined zero position.

For sound radiation through the transducer head 1 5 pulsations are first introduced into the first chamber 15 via the inlet opening. The pulsations introduced into the first chamber 15 force a deflection of the excitation membrane 13 from its zero position and an oscillation thereof. The pulsations superimposed low-frequency pressure fluctuations, in particular static pressure differences, are compensated for via the connecting tube 19 between the first and second chambers 15 and 17 . This prevents tensioning of the excitation membrane 13 . The damping element 21 also ensures that high-frequency pressure changes are not passed on from the first chamber 15 to the second chamber 17 . The vibrations of the excitation membrane 13 are transmitted via the center plate 23 to the coupling rod 25 , whereby the Schallab radiation membrane 31 is set in vibration and thus the desired Schallab radiation occurs.

It is thus achieved by the transducer head 1 according to the invention that an unhindered sound radiation takes place independently of low-frequency pressure fluctuations. Fer ner a connection of the inlet opening 5 with the surrounding atmosphere, as is undesirable for the emission of exhaust gas pulsations, can be avoided.

The Schallabstrahlcharakteristiken of the transducer head 1 can the sound transducer head 1 supplied pulsations are adapted in various ways. For example, the shape of the sound radiation area 9 can be used to vary the desired radiation characteristic. Furthermore, the vibration of the membranes 13 and 31 can be varied in particular by adjusting the damping element 21 , the spring elements 37 and / or 39 and the voltage before the membranes 13 and / or 31 . The volume, in particular in the first chamber 15 and the feed line (not shown) can be adjusted to form a Helmholtz resonator.

In FIG. 2, a second embodiment of the transducer head 1 according to the invention represented '. Identical elements of the transducer head 1 'of FIG. 2 in comparison to the transducer head 1 of FIG. 1 have the same reference numerals. In contrast to the transducer head 1 of FIG. 1, the transducer head 1 'of FIG. 2 comprises a stimulation membrane 13 ' and a sound radiation membrane 31 'which have areas of different flexibility. The excitation membrane 13 'that is has a border 13' on a, in comparison to the central region 13 b has a higher flexibility '. Analogously, the sound radiation membrane 31 ′ has an edge region 31 ′ a, which has greater flexibility than its central region 31 ′ b. This embodiment of the membranes 13 'and 31 ' makes it possible to adjust the sound radiation characteristics of the transducer head 1 ', in addition to changing the bias of the membranes 13 ' and 31 ', by changing the size of the areas of different flexibility and / or the difference in flexibility.

However, an inventive transducer head does not have to encompass a double membrane system, but instead may have a body sound exciter instead of an acoustically active sound radiation membrane. Such an embodiment of the sound according to the invention transducer head 1 "shown in Fig. 3. The same elements of the transducer head 1" of FIG. 3 compared to the transducer heads 1 and 1 'of Figs. 1 and 2 carry the same reference numerals. In the transducer head 1 ", the coupling rod 25 'is connected on the one hand to the center plate 23 of the excitation membrane 13 ', but there is a plunger 41 at the upper end of the coupling rod 25 '. The transducer head 1 " is also connected to a body 45 via connecting elements 43 connected, so that pulsations supplied via the inlet opening 5 lead to vibrations of the excitation membrane 13 'and finally to impacts of the tappet 41 on the body 45 , whereby the body is excited to emit sound waves. In a suitable design of the connecting elements 43 , the fourth chamber 47 between the body 45 and the partition 7 serves as a resonance body, so that the characteristics of the sound generated by the body 45 can be changed via the dimensioning of this chamber 47 .

In FIG. 4 is a fourth embodiment of a transducer head 1 according to the invention '''is shown. In contrast to the embodiments of the transducer head according to the invention shown in FIGS. 1 and 2, a transmission of the vibrations of the excitation membrane 13 "to the sound radiation membrane 31 is carried out electromechanically. For this purpose, the center plate 23 of the excitation membrane 13 " is connected via a rod 49 with an electromagnetic-mechanical scanning device 51 , which comprises, for example, a piezoelectric element. The signals picked up by the scanning device 51 are forwarded to a control device 55 via a line 53 . This control device 55 is connected via a line 57 to a drive device 59 . At the drive device 59 is connected via a rod 61 to the center plate 35 of the sound radiation membrane 31 . In contrast to the previous embodiments of the OF INVENTION to the invention transducer head of the pressure equalization between the is achieved by the Anre supply membrane 13 "separate chambers 15 and 17 in the transducer head 1 '''of Fig. 4 through openings 63 in the excitation membrane 13". The openings 63 are filled with a damping element, not shown, in the form of foam. This foam ensures that only low-frequency pressure fluctuations are transmitted through the openings 63 , but not high-frequency fluctuations.

An oscillation of the excitation membrane 13 "of the transducer head 1 '''of FIG. 4 leads to vibration signals being forwarded to the control device 55 via the scanning device 51. Depending on the desired sound radiation characteristic, the vibration signals are processed in the control device 55 in such a way that a desired oscillation of the sound radiation membrane 31 is achieved to the signals emitted to the drive device 59. In addition, it is provided that the control device 55 is supplied via a line 65 with further signals which influence the signals emitted to the drive device 59. These signals lead to the fact that Various environmental parameters, such as when using the transducer head 1 '''in a motor vehicle, the speed of the internal combustion engine, the accelerator pedal position or the type of gear engaged influence the signals which are sent to the drive device 59 .

According to the invention, a transducer head is therefore provided for the first time, which one allows unimpeded sound radiation at different static pressures and in can be matched in many ways to a desired radiation pattern.

The open in the above description, in the drawings and in the claims Beard features of the invention can be used both individually and in any combination nation for the implementation of the invention in its various embodiments we be substantial.  

LIST OF REFERENCE NUMBERS

1

.

1

'

1

'' '

1

'''Transducer head

3

casing

5

inlet port

7

partition wall

9

Sound radiation area

11

horn

13

.

13

'

13

"Excitation membrane
13'a edge area
13'b middle area

15

.

17

chamber

19

connecting pipe

21

damping element

23

medium plates

25

.

25

'' Coupling rod

27

Simerring

29

chamber

31

.

31

'' Sound radiation membrane
31'a edge area
31'b middle area

33

chamber

35

medium plates

37

spring element

39

spring element

41

tappet

43

fasteners

45

body

47

chamber

49

pole

51

scanning

53

management

55

control device

57

management

59

driving means

61

pole

63

opening

65

management

Claims (15)

1. transducer head, with at least one inlet opening ( 5 ) for a supply line, at least a first minimum membrane ( 13 , 13 ', 13 ") and at least one sound radiation area ( 9 ) in a housing ( 3 ), characterized by
an essentially airtight partition ( 7 ) by means of which the housing ( 3 ) is divided into at least two sections, the first section being operatively connected to the inlet opening ( 5 ) and the second section being connected to the sound radiation area ( 9 ) Membrane ( 13 , 13 ', 13 ") is arranged in the first section and divides the same into a strip ( 15 ) and a second chamber ( 17 ),
a pressure compensation device ( 19 , 21 , 63 ) between the first ( 15 ) and the second chamber ( 17 ), a pulsation conversion element ( 31 , 31 ', 41 ) which is arranged at least partially movably in the second section, and
a transmission device ( 25 , 25 ', 49 , 51 , 59 , 61 ) between the first and second section for transmitting vibrations of the first membrane ( 13 , 13 ', 13 ") to the pulsation conversion element ( 31 , 31 ', 41 ). 2. A transducer head according to claim 1, characterized in that the pressure compensation device has at least one connection opening ( 63 ) in the first membrane ( 13 "), in one with the first membrane ( 13 , 13 ', 13 ") and the transmission device ( 25 , 25 ', 49 , 51 ) operatively connected connecting member ( 23 ) and / or between the first membrane ( 13 , 13 ', 13 ") and the housing ( 3 ) and / or a bypass ( 19 , 21 ). 3. transducer head according to claim 2, characterized in that the pressure compensation device at least one, preferably in its damping properties adjustable damping element ( 21 ), in particular in the form of a variable cross-sectional reduction, a labyrinth and / or a porous material such as foam, iron wool and / or the like. 4. A transducer head according to one of the preceding claims, characterized in that the geometric dimensions of the first section, in particular the first ( 15 ) and / or second chamber ( 17 ), the inlet opening ( 5 ), the feed line and / or the second section, in particular the sound radiation area ( 9 ), preferably during operation of the transducer head ( 1 , 1 ', 1 ", 1 ""), can be changed. 5. A transducer head according to claim 4, characterized in that the sound radiation area ( 9 ) is substantially horn-shaped ( 11 ). 6. A transducer head according to one of the preceding claims, characterized in that the pulsation conversion element has at least one second membrane ( 31 , 31 ") which divides the second section into a third ( 29 ) and fourth chamber ( 33 ), and / or at least one Structure-borne noise generator, in particular comprising a plunger ( 41 ), for mechanical excitation of an at least partially in the sound radiation area ( 9 ) arranged body ( 45 ), in particular comprising the housing ( 3 ). 7. transducer head according to claim 6, characterized in that the transmission device at least one, in particular rigid ( 25 , 25 '), mechanical, electromechanical ( 49 , 51 , 59 , 61 ) and / or magnetomechanical coupling element and / or at least one positioning device ( 37 , 39 ). 8. transducer head according to claim 7, characterized by at least one sealing device, preferably in the form of a simer ring ( 27 ), for storing and carrying out the coupling element ( 25 , 25 '). 9. A transducer head according to claim 7 or 8, characterized in that the electromechanical coupling element at least one, preferably electromagnetic cal sensing device ( 51 ) for sensing the vibrations of the first membrane ( 13 ") and a, preferably electromagnetic, drive device ( 59 ) Drive of the pulsation conversion member ( 31 ) comprises. 10. A transducer head according to one of claims 7 to 9, characterized in that the positioning device comprises at least one spring element ( 37 , 39 ) in the first ( 15 ), second ( 17 ), third ( 29 ) and / or fourth chamber ( 33 ) and / or during operation of the transducer head ( 1 , 1 ', 1 ", 1 "') is controllable and / or adjustable. 11. A transducer head according to one of the preceding claims, characterized by a control and / or regulating device ( 55 ) for controlling and / or regulating the sound radiation characteristics, in particular in operative connection with the partition ( 7 ), the first membrane ( 13 , 13 ', 13 "), the damping element ( 21 ), the pulsation conversion element ( 31 , 31 ', 41 ), a signal transmitter for at least one further external signal influencing the sound radiation characteristic and / or the transmission device ( 25 , 25 ', 49 , 51 , 59 , 61 ). 12. A transducer head according to one of the preceding claims, characterized in that the first ( 13 , 13 ', 13 ") and / or second membrane ( 31 , 31 ') comprises an elastomer, a reinforcing fabric, a plastic and / or a sheet metal or include. 13. A transducer head according to one of the preceding claims, characterized in that the first ( 13 , 13 ', 13 ") and / or second membrane ( 31 , 31 ') strengthen different membranes, have different flexibilities and / or different shapes , preferably for providing a stiffer central region (13'b, 31'b) and a more flexible edge region (13'a, 13'b). 14. A transducer head according to one of the preceding claims, characterized in that the bias of the first ( 13 , 13 ', 13 ") and / or second membrane ( 31 , 31 ') and / or the size of at least one region of the first ( 13 , 13 ', 13 ") and / or second membrane ( 31 , 31 '), in particular during operation of the transducer head ( 1 , 1 ', 1 ", 1 '''), is or can be controlled and / or regulated , 15. Sound transducer in an exhaust gas and / or intake area of an internal combustion engine, in particular a motor vehicle, with a sound transducer head ( 1 , 1 ', 1 ", 1 "") according to one of the preceding claims.