WO2020020615A1

WO2020020615A1 - Vehicle body having a trim point for attachment of a trim mass, and method for adjusting acoustic properties of a vehicle

Info

Publication number: WO2020020615A1
Application number: PCT/EP2019/068234
Authority: WO
Inventors: Alfred IRRGANG; Markus Kohlhuber; Johannes MAYET
Original assignee: Bayerische Motoren Werke Aktiengesellschaft
Priority date: 2018-07-27
Filing date: 2019-07-08
Publication date: 2020-01-30
Also published as: CN112119002A; CN112119002B; DE102018212546A1

Abstract

The invention relates to a vehicle body (100) for a vehicle. The vehicle body (100) comprises an occupant cabin (101) for at least one occupant of the vehicle. The vehicle body (100) additionally comprises at least one trim point (301, 302, 303), which is designed for the fixing of at least one trim mass (320, 330) to the vehicle body (100), such that an acoustic property of the occupant cabin (101) is changed by the trim mass (320, 330).

Description

Vehicle body with trim point for connecting a trim mass, and method for setting the acoustic properties of a vehicle

The invention relates to a method for adjusting the acoustic

Properties of a vehicle body for a vehicle. Furthermore, the invention relates to a vehicle body, which has means with which the acoustic properties of the vehicle body can be adjusted.

The vehicle body for a vehicle typically forms one

Passenger cabin for one or more occupants of the vehicle. The

If possible, the vehicle body is designed such that the

Occupant cabin has certain acoustic properties, in particular in relation to low-frequency acoustic vibrations in a frequency range between 30 Hz and 100 Hz.

The acoustic properties of the vehicle body are typically set during the development of a vehicle by means of a computer-based vibration model of the vehicle body. This can lead to deviations between the calculations of the vibration model and the actual acoustic properties of the manufactured vehicle body of a vehicle. Such deviations can be relatively high

Lead efforts for adaptation measures to the vehicle body to achieve the desired acoustic properties.

The present document deals with the technical task of adapting the acoustic properties of a vehicle body that has already been manufactured to the desired acoustic properties in an efficient and precise manner. The task is solved in each case by the independent claims. Advantageous embodiments are described, inter alia, in the dependent claims. It is pointed out that additional features are one of one

independent claim independent of the features of the independent claim or only in combination with a subset of the features of the independent claim can form their own invention and independent of the combination of all features of the independent claim, which is the subject of an independent claim, a divisional application or a subsequent application can be made. This applies in the same way to the technical teachings described in the description, which can form an invention which is independent of the features of the independent claims.

In one aspect, a vehicle body for a vehicle is described. The vehicle body can e.g. a metal and / or one

Include fiber composite. The vehicle can be a motor vehicle, in particular a road motor vehicle. The vehicle body includes an occupant cabin for at least one occupant of the vehicle. The occupant cabin can form a space, in particular a closed space, in which one or more occupants can be accommodated. For example, one or more seats and / or benches on the in the occupant cabin

Vehicle body are attached, on which one or more occupants can sit.

The vehicle body may have been developed to provide an occupant cabin with one or more specific acoustic properties.

In particular, the goal of the development of the vehicle body may have been to provide an occupant cabin which (in response to a specific excitation) has a nominal frequency profile of an acoustic load (caused by the occupant cabin and / or the vehicle body). The acoustic load can be caused, for example, by a sound level within the Occupant cabin and / or be described by a volume of the occupant cabin. A nominal can therefore be used for the vehicle body

Frequency curve of the sound level and / or volume can be provided The frequency curve can cover a frequency range from a lower frequency (e.g. lOHz, 20Hz, 30Hz or more) to an upper frequency (e.g. lOOHz, 90Hz, 80Hz or less) Frequency range may be limited. Low frequency acoustic vibration properties of the vehicle body can thus be described by the frequency curve.

As part of the development of the vehicle body, a computer-based and / or mathematical vibration model of the vehicle body can be created

provided and / or created to describe the vibration behavior and / or the acoustic behavior of the vehicle body and in particular the occupant cabin. The vibration model can have a plurality of parameters, each with a possible range of values. The possible value range of a parameter can depend on possible tolerances in the manufacture of the vehicle body and / or on possible inaccuracies and / or uncertainties of the vibration model. The

Vibration model of the vehicle body can be designed for the possible value ranges of the plurality of parameters, a plurality of frequency profiles with respect to the acoustic load within the

Provide occupant cabin. A (possibly more probable) frequency curve can be the nominal frequency curve.

Due to the said manufacturing tolerances and / or due to

Inaccuracies and / or uncertainties of (when developing the

Vehicle body used) vibration model, it may happen that the vehicle body actually manufactured is an actual one

Frequency curve with respect to the acoustic load (for example for the sound level and / or for the volume) has significantly different from the nominal Frequency curve of the vehicle body deviates. In particular, the actual frequency curve can have a maximum value of the acoustic load (for example the sound level and / or the rapid volume) which is significantly higher than the maximum value of the nominal frequency curve. The vehicle body actually manufactured can thus possibly have an acoustic load which is significantly higher than that during the development of the

Vehicle body planned acoustic load is (e.g. an increased acoustic load when driving over a rough road surface).

The vehicle body comprises at least one trim point, which is used for

Attachment of at least one trim compound is formed on the vehicle body. The trim point can be arranged on the vehicle body in such a way that an acoustic property of the occupant cabin can be changed by the trim mass. In particular, the trim point on the

Vehicle body can be arranged that the actual frequency curve of the acoustic load within the occupant cabin can be changed by the trim mass, in particular approximated to the nominal frequency curve. The trim point on the

Vehicle body that be arranged by the trim mass

Maximum value of the actual frequency profile of the acoustic load can be reduced.

A vehicle body is therefore described which was developed and manufactured directly with one or more trim points for connecting or fastening trim masses. In particular, in the development and / or manufacture of the vehicle body and / or the vehicle

Fastening mechanisms and / or the space required for one or more trim masses may have been provided. One or more trim measures can then be attached to the vehicle body in an efficient manner after completion of the development of a vehicle body and / or after production of a vehicle body, in order to avoid deviations from the original to compensate for the planned, nominal acoustic properties of the vehicle body.

A trim mass can comprise a unit with a certain mass or with a certain weight that can be attached (e.g. screwed) to the vehicle body. Alternatively or in addition, the trim mass can include an absorber. Alternatively or additionally, the trim compound can comprise a sprayable material (e.g. an anti-droning material) which is suitable for the

Vehicle body is sprayed. A trim mass can have a weight of 100 g, 150 g, 200 g, 250 g, 300 g, 350 g, 500 g, 100 g or more. Different trim weights with different weights (e.g. in 50g steps) can be provided.

A trim point arranged on the vehicle body can be a

Fastening element, in particular a screw and / or a screw nut, which is designed to form a (non-positive and / or positive) connection with a complementary fastening element of a trim mass in order to fasten the trim mass to the vehicle body. The trim mass can thus be efficiently e.g. are attached to the vehicle body by a screw connection.

The vehicle body can comprise a supporting body part (for example a roof or a shelf). The supporting body part can, for example, be part of a wall of the occupant cabin of the vehicle. Furthermore, the vehicle body or the vehicle comprising the vehicle body can comprise a covering which covers the supporting body part at least in regions. A cavity or an installation space can then be provided between the body part and the cladding for receiving a trim compound. This cavity can possibly remain empty if no trim compound has to be attached to the vehicle body in order to adjust or trim one or more acoustic properties of the vehicle body. On the other hand, there is Cavity available if the acoustic properties of the vehicle body actually manufactured should or must be changed.

The cavity can be formed, a layer (for example a layer with a thickness of 2 mm, 5 mm, 10 mm or more or with a flat dimension of 10 cm ² , 100 cm ² , 500 cm ² _, 1000 cm ² , 2000 cm ² or more) from a sprayable Material, especially an anti-boom material, as a trim compound

take. In this way, a trim compound can be attached to the vehicle body in an efficient and precise manner.

The vehicle body can comprise at least one bow (e.g. on the A,

B and / or C pillar of the vehicle). The bow can be arranged on the roof of the vehicle body. Furthermore, the bow can run along a transverse axis of the vehicle body (i.e. transverse to the direction of travel of the vehicle). The vehicle body can have at least one trim point arranged on the bow. By arranging a trim point on a bow, the occupant's cabin can be influenced in an efficient manner (i.e. with a trim mass with the lowest possible weight), in particular the frequency profile of the acoustic load.

The vehicle body can be one within the occupant cabin

Rear area arranged shelf, in particular a rear shelf. Furthermore, the vehicle body can have at least one on the shelf

have arranged trim point. By arranging at least one trim point on a shelf of the occupant cabin, the acoustic properties of the vehicle body can be changed in a particularly efficient manner.

The vehicle body can comprise at least one sheet-like body part (for example the roof or a shelf) as part of a wall of the occupant cabin. The sheet-like body part can form, for example, 10%, 20% or more of the area of the wall of the occupant cabin. The vehicle body can thus have a relatively large body part. Furthermore, the

Vehicle body have at least one trim point arranged on the sheet-like body part. By providing one or more trim points on a relatively large body part, the acoustic properties of the vehicle body can be changed in a particularly efficient manner.

As already explained above, the vehicle body may have been developed on the basis of a mathematical vibration model, e.g. with the aim that the vehicle body or the passenger cabin have a certain nominal frequency profile of the acoustic load (e.g. the sound level and / or the volume).

The vibration model of the vehicle body can be designed to provide a multiplicity of frequency profiles with respect to the acoustic load within the occupant cabin for the possible value ranges of the plurality of parameters of the vibration model. The at least one trim point can be arranged on the vehicle body in such a way that the maximum values of the N frequency profiles from the plurality of frequency profiles that have the N highest maximum values are reduced (where N is an integer with N> 0, in particular N = 3 , 5, 10 or more). In particular, the at least one trim point can be arranged in such a way that the maximum values can each be reduced by 30%, 40%, 50% or more (with a trim mass that has a certain maximum weight (for example 1.5 kg) and / or a certain maximum volume ( e.g. 10,000 cm ³ ).

On the basis of a vibration model of the vehicle body, positions of one or more trim points of the vehicle body can be determined by which an efficient and significant change in the Frequency curves of the acoustic load for the N "worst case"

Frequency profiles can be effected. An efficient change aims at the use of one or more trim weights with the lowest possible weight (e.g. with a total weight of the trim weights of 2.5 kg, 1.5 kg or less). A significant change aims to reduce the maximum values of the N "worst case" as much as possible.

Frequency curves from (e.g. by 30%, 40%, 50% or more).

As stated above, the vehicle body may have been developed to have a nominal frequency response with respect to acoustic loading within the occupant cabin. The at least one trim point of the

The vehicle body can be such that a trim mass is only attached to the trim point on the vehicle body if an actual frequency curve with respect to the acoustic load within the

Passenger cabin deviates (substantially) from the nominal frequency response. In particular, a trim mass can only be attached to the trim point on the vehicle body if the maximum value of the actual frequency response exceeds the maximum value of the nominal frequency response, e.g. at least 20%, 30%, 40%, 50% or more. As an alternative or in addition, the trim mass may only be at the trim point on the

Vehicle body are attached when the maximum value of the actual frequency response reaches or exceeds a certain threshold. The trim point can thus, if necessary, only be used exclusively to attach a trim compound to the vehicle body, if necessary, in order to change the acoustic properties of the vehicle body.

The at least one trim point of the vehicle body can be designed and provided such that a trim mass can be attached to the trim point on the vehicle body in order to determine the actual frequency profile of the vehicle body with the trim mass attached to the nominal

Frequency curve to sew. Alternatively or in addition, the at least one Trimming point of the vehicle body can be designed and provided such that a trimming mass can be attached to the trimming point on the vehicle body in order to reduce the maximum value of the actual frequency profile of the vehicle body with the trimming mass attached to the maximum value of the actual frequency profile of the vehicle body without trimming mass (in particular by 20 %, 30%, 40%, 50% or more).

According to a further aspect, a method for setting an acoustic property of a vehicle body of a vehicle is described. The vehicle body includes an occupant cabin for at least one occupant of the vehicle. Furthermore, the vehicle body comprises at least one trim point for fastening a trim mass. The method can e.g. be carried out as part of the production of the vehicle body (e.g. by a production robot).

The method includes determining whether an actual frequency profile with respect to an acoustic load within the occupant cabin deviates significantly from a nominal frequency profile. For this purpose, a measurement can be carried out to determine the actual frequency curve. A significant deviation can e.g. are present if the

Maximum value of the actual frequency response is 10%, 20%, 30% or more above the maximum value of the nominal frequency response.

The method also includes attaching a trim mass to the trim point when it is determined that the actual frequency response is significantly different from the nominal frequency response. On the other hand, no trim mass is typically attached to the trim point if it has been determined that the actual frequency response does not differ significantly from the nominal frequency response. So acoustic properties of the

Passenger cabin of a vehicle body can be set in an efficient and precise manner. The method may include determining a weight of the trim mass to be attached to the trim point. For this purpose, a

(Mathematical) vibration model of the vehicle body are provided, which is designed to provide a plurality of frequency profiles with respect to the acoustic load within the occupant cabin for possible value ranges of a plurality of model parameters. The vibration model can e.g. be created and / or used as part of the development of the vehicle body. The weight of the trim mass that is or should be attached to the trim point can then be determined in an efficient and precise manner on the basis of the vibration model.

According to a further aspect, a road motor vehicle (in particular a passenger car or a fast motor vehicle or a bus) is described which comprises the vehicle body described in this document.

It should be noted that the methods, devices and systems described in this document can be used both alone and in combination with other methods, devices and systems described in this document. Furthermore, all aspects of the methods, devices and systems described in this document can be combined with one another in a variety of ways. In particular, the features of the claims can be combined with one another in a variety of ways.

The invention is described in more detail below on the basis of exemplary embodiments. Show

Figure 1 shows an exemplary vehicle body;

Figure 2 exemplary frequency profiles of the volume of the

Vehicle body or the occupant cabin of the vehicle body;

FIG. 3a exemplary trim points on a vehicle body;

FIGS. 3b and 3c show exemplary trim measures; FIG. 3d exemplary frequency profiles of the rapid volume with and without trim masses;

Figure 3e exemplary trim points on a vehicle body; and

FIG. 4 shows a flowchart of an exemplary method for setting the acoustic properties of a vehicle body.

As stated at the beginning, the present document deals with the efficient setting, in particular the readjustment, of acoustic properties of a vehicle body. In this context, FIG. 1 shows an exemplary vehicle body 100 of a passenger car (passenger car). The vehicle body 100 forms an occupant cabin 101, which is closed at the top by a vehicle roof 102. The vehicle roof 102 typically forms a relatively large (vibratable) area. Furthermore, the body 100 can optionally have a shelf, in particular a rear shelf, 103 in the rear area. The occupant cabin 101 can have an A pillar 105 (in the front area), a central B pillar 106 and a C pillar 107 in the rear area.

As part of the development of a vehicle body 100, a

Vibration model of the vehicle body 100 can be created. The

Vibration model can have one or more parameters, such as the mass of different components of the vehicle, the modulus of elasticity of a component of the vehicle (for example a door seal) and / or one

Degree of absorption of a component of the vehicle (e.g. one

Interior paneling, a carpet, etc.).

The acoustic properties of the vehicle body 100 can be analyzed on the basis of the vibration model of the vehicle body 100. An example of a measurement of the acoustic properties is the volume of volume of the occupant cabin 101. FIG. 2 shows a large number of frequency profiles 200 of the volume of volume of the occupant cabin 101 as a function of the frequency 201, in particular in a frequency range between 30 Hz and 100 Hz. One or more parameters of the vibration model were varied in certain value ranges in order to determine the multiplicity of frequency profiles 200. An average frequency profile can be made from the plurality of frequency profiles 200

203 can be determined. 2 also shows a nominal frequency response

204 for the vehicle body 100, which corresponds to the originally planned or the target frequency profile for the vehicle body 100.

It can be seen from FIG. 2 that the actual frequency profile of the volume rapid can deviate significantly from the nominal frequency profile 204. In particular, the actual frequency curve can have a maximum value 202 of the volume frequency that is significantly above the maximum value of the volume speed of the nominal frequency profile 204. This can result in unpleasant noises in the occupant cabin 101 when a vehicle is in operation.

3a shows the vehicle body 100 with three exemplary trim points or connection points 301, 302, 303 for connecting trim masses. FIG.

3e shows further exemplary trim points 301 (as white circles)

different locations of the vehicle body 100. One or more

Trimming points 301, 302 can be arranged on the roof 102 of the vehicle body 100, in particular on one or more bars 340 of the vehicle body 100 (see FIG. 3e). Alternatively or in addition, one or more trim points 303 can be arranged on the rear shelf 103 of the vehicle body 100.

The one or more trim points 301, 302, 303 can each be designed to accommodate a trim mass. 3b shows a trim point 301, 302, 303, in which a screw-in nut 311 is provided in the body part 310 of the body 100 in order to be able to fasten a trim mass 320 to the body 100 with a screw 321. 3c shows a trim point 301, 302, 303, in which a sufficiently large cavity or installation space 313 is provided between the body part 310 and a covering 312 of the occupant cabin 101 in order to be able to fix a sprayable covering (in particular an anti-droning covering) as a trim compound 330 on the body part 310 ,

A vehicle body 100 can thus be provided which has one or more trim points 301, 302, 303, to which a trim mass 320, 330 can be attached, if necessary, in order to change the acoustic properties of the vehicle body 100. If e.g. After the development and manufacture of a vehicle body 100 reveals that acoustic properties of the manufactured vehicle body 100 differ from desired or planned acoustic properties of the vehicle body 100, one or more trim weights 320, 330 at the one or more trim points 301, 302, 303 are attached to the vehicle body 100 in order to correct the acoustic properties of the manufactured vehicle body 100.

FIG. 3d shows an exemplary frequency profile 331 of the volume of the occupant cabin 101 of a manufactured vehicle body 100. From FIG. 3d it can be seen that the frequency profile 331 has a relatively high maximum value 202 which can lead to acoustically unpleasant vibrations of the occupant cabin 101. By applying one or more trim masses 320, 330, a corrected frequency curve 332 of the volume rapid can be effected. As can be seen from FIG. 3d, the maximum value 202 of the original frequency curve 331 can be reduced in the corrected frequency curve 332.

To determine suitable positions for the one or more trim points 301, 302, 303, parameters of the vibration model of the vehicle body 100 can be used that have a relatively strong influence on the result of the

Vibration simulation of the vehicle body 100 have, and the values of which are not exactly known (ie which vary within a certain range of values can be analyzed. A possible range of values, ie a possible range of values (for example by analysis or

Estimate). A stochastic calculation model can then be made of the possible dispersion of the acoustic properties (e.g. the

Rapid volume) of the vehicle body 100 (as shown, for example, in FIG. 2). This results in a multitude of solutions that can be statistically evaluated. In particular, the possible range of acoustic properties (in particular frequency profiles 200 of the volume-fast) can be determined.

It can be based on the simulated range of possible acoustic

Properties (especially based on the multitude of possible

Frequency profiles 200 of the volume-fast), a number of outliers are analyzed (which, for example, have a particularly high maximum value 202). The one or more trim points 301, 302, 303 and / or the values of one or more trim measures 320, 330 can then be determined on the basis of the limited number of outliers, in particular in such a way that the

Maximum values 202 can be reduced in each case.

To determine the standing of one or more trimming points 301, 302, 303 and / or to determine the values of the one or more trimming masses 320, 330, one or more stands of the vibration model can be used to determine the standing of the

Vehicle body 100 trim points 301, 302, 303 and trim masses 320, 330 are taken into account. The supplementary vibration model can then be used to analyze where the one or more trim weights 320, 330 should be arranged on the vehicle body 100 in order to reliably and efficiently compensate for the possible outliers in the acoustic properties of the vehicle body 100 (ie with the lowest possible mass) can. The positions of the one or more trim points 301, 302, 303 can thus be determined on the basis of a supplemented vibration model. FIG. 4 shows a flow diagram of an exemplary method 400 for

Setting an acoustic property of a vehicle body 100 of a vehicle. The vehicle body 100 includes an occupant cabin 101 for at least one occupant of the vehicle. Furthermore, the

Vehicle body 100 at least one trim point 301, 302, 303 for

Attaching a trim compound 320, 330. The method 400 can e.g. during manufacture or following the manufacture of a vehicle body 100 (e.g. by a robot).

The method 400 includes determining 401 whether an actual one

Frequency curve 200 with respect to an acoustic load within the occupant cabin 101 (e.g. a frequency curve of the sound level and / or the volume rapid) deviates significantly from a nominal frequency curve 204. Furthermore, the method 400 includes attaching 402 a trim mass 320, 330 to the trim point 301, 302, 303 (if necessary only) if it has been determined that the actual frequency profile 200 deviates significantly from the nominal frequency profile 204. In this way, deviation of the actual frequency profile 200 from the nominal frequency profile 204 can be at least partially compensated for. On the other hand (if there are no significant deviations) it is not necessary to attach a trim mass 320, 330.

The measures described in this document make it possible to develop and / or manufacture a late

Vehicle body 100 to adjust or tune the acoustic properties of vehicle body 100 in a cost and weight efficient manner. Furthermore, a functional wet construction is made possible, since measures that affect the entire scatter band of acoustic properties can be distinguished from measures that may outlap acoustic ones

Resolve properties (such as those described in this document

Activities). The present invention is not restricted to the exemplary embodiments shown. In particular, it should be noted that the description and the figures are only intended to illustrate the principle of the proposed methods, devices and / or systems.

Claims

Expectations

1) vehicle body (100) for a vehicle, the vehicle body (100) comprising

- an occupant cabin (101) for at least one occupant of the vehicle; and

- at least one trim point (301, 302, 303), which is designed to attach at least one trim mass (320, 330) to the vehicle body (100), so that the trim mass (320, 330) creates an acoustic property of the occupant cabin (101) is changed.

2) Vehicle body (100) according to claim 1, wherein the trimming point (301, 302, 303) comprises a fastening element (311), in particular a screw and / or a screw nut, which is designed with a complementary fastening element (321) of a trimming compound (320, 330) to form a connection to the trim mass (320, 330) on the

Fasten the vehicle body (100).

3) vehicle body (100) according to any one of the preceding claims, wherein

- The vehicle body (100) is a supporting body part (310)

includes;

- The vehicle body (100) comprises a covering (312) which covers the supporting body part (310) at least in regions; and

- Between the body part (310) and the panel (312)

Cavity (313) is provided for receiving a trimming compound (320, 330).

4) vehicle body (100) according to claim 3, wherein the cavity (313) is formed, a layer (320) made of a sprayable material,

especially an anti-droning material, as a trim compound (320, 330) take.

5) vehicle body (100) according to any one of the preceding claims, wherein

- The vehicle body (100) comprises at least one bow (340);

- The bow (340) in particular on a roof (102) of the

Vehicle body (100) is arranged;

- The bow (304) in particular along a transverse axis of the

Vehicle body (100) runs; and

- The vehicle body (100) has at least one trim point (301, 302, 303) arranged on the bow (340).

6) vehicle body (100) according to any one of the preceding claims, wherein

- The vehicle body (100) comprises a shelf (103), in particular a rear shelf, arranged inside the occupant cabin (101) in a rear area; and

- The vehicle body (100) has at least one trim point (301, 302, 303) arranged on the shelf (103).

7) vehicle body (100) according to any one of the preceding claims, wherein

- The vehicle body (100) at least one flat

Body part (310) as part of a wall of the occupant cabin (101) comprises;

- The sheet-like body part (310) forms in particular 20% or more of an area of the wall of the occupant cabin (101); and

- The vehicle body (100) has at least one trim point (301, 302, 303) arranged on the sheet-like body part (310).

8) vehicle body (100) according to any one of the preceding claims, wherein - The vehicle body (100) based on a mathematical

Vibration model was developed;

- The vibration model has a plurality of parameters, each with a possible range of values;

- The possible value range of a parameter, in particular of

possible tolerances in the manufacture of the vehicle body (100) and / or depends on possible inaccuracies and / or uncertainties of the vibration model;

- The vibration model of the vehicle body (100) is designed to provide a plurality of frequency profiles (200) for the possible value ranges of the plurality of parameters with respect to an acoustic load within the occupant cabin (101);

- The at least one trim point (301, 302, 303) in this way on the

Vehicle body (100) is arranged such that a maximum value (202) of the N frequency profiles (200) from the plurality of frequency profiles (200) with the N highest maximum values (202) is reduced, in particular by 30%, 40%, 50% or more ; and

- N is an integer, with N> 0, in particular N = 3, 5, 10 or more.

9) vehicle body (100) according to any one of the preceding claims, wherein

- The vehicle body (100) was developed to have a nominal frequency curve (204) with respect to an acoustic load within the occupant cabin (101); and

- A trim mass (320, 330) is only attached to the trim point (301, 302, 303) on the vehicle body (100) if an actual frequency curve (200) with respect to the acoustic load within the occupant cabin (101) of the nominal frequency curve (204) deviates; and or

- A trim mass (320, 330) is only attached to the trim point (301, 302, 303) on the vehicle body (100) when a maximum value (202) of the actual frequency response (200) is one Maximum value (202) of the nominal frequency response (204) exceeds, in particular by 20%, 30%, 40%, 50% or more; and or

- A trim mass (320, 330) at the trim point (301, 302, 303) on the vehicle body (100) is attached to the actual frequency response (200) of the vehicle body (100) with attached trim mass (320, 330) at the nominal Frequency curve (204) to sew; and or

- A trim mass (320, 330) at the trim point (301, 302, 303) is attached to the vehicle body (100) by a maximum value (202) of the actual frequency response (200) of the vehicle body

(100) with attached trim mass (320, 330) compared to a maximum value (202) of the actual frequency response (200) of the vehicle body (100) without trim mass (320, 330).

10) Method (400) for setting an acoustic property of a

Vehicle body (100) of a vehicle; the vehicle body (100) comprising an occupant cabin (101) for at least one occupant of the vehicle; the vehicle body (100) comprising at least one trim point (301, 302, 303) for fastening a trim mass (320, 330); the method (400) comprising

- determining (401) whether an actual frequency response (200)

regarding acoustic stress inside the occupant cabin

(101) deviates significantly from a nominal frequency response (204); and

- Attaching (402) a trimming mass (320, 330) to the trimming point (301, 302, 303), in particular only if it has been determined that the actual frequency profile (200) deviates significantly from the nominal frequency profile (204).

11) The method (400) according to claim 10, wherein the method (400) comprises - Providing a vibration model of the vehicle body (100), which is designed to provide a plurality of frequency profiles (200) with respect to the acoustic load within the occupant cabin (101) for possible value ranges of a plurality of model parameters; and

- Determine a weight of the trim mass (320, 330), which on the

Trimming point (301, 302, 303) is attached, based on the

Vibration model.