FR2745874A1 - DEVICE FOR DELETING RELATIVE MOVEMENTS BETWEEN COMPONENTS OF AN INSTALLATION - Google Patents

Abstract

The invention relates to a device for eliminating relative movements between components of an installation. In this device comprising a rigid platform (6) on which components of an installation are mounted or are rigidly connected to the latter and comprising a frame-shaped structure (100) and a receiving unit (9), the frame-shaped structure has profiled parts (1a to 1d; 2a to 2d; 3a to 3d) interconnected by connecting gussets (4) so that neighboring profiled parts are separated by a distance such that the structure frame-shaped is flexible and dampens vibrations, displacement and other disturbances. Application in particular to vibration damping systems in a structure placed inside an airplane.

Description

DEVICE FOR DELETING RELATIVE DISPLACEMENTS BETWEEN

COMPONENTS OF AN INSTALLATION

  The invention relates to a device for suppressing

  relative movements between components of an instru-

tallation.

  Devices, which consist of different

  Individual components which are not directly connected to one another, for example, should be designed for the execution of measurements or tests so that the individual components do not move relative to each other, or move as little as possible to each other. This must in particular be the case also when the entire device is moved for example in an aircraft. During a flight, there appears, inside the plane, vibrations, displacements or

  similar disturbances, which should not be trans-

  put on the device or be transmitted only to a degree as low as possible, to obtain meaningful results.

  To avoid such disturbances, it is necessary to

  see between the installation or the individual components of the device and the receiving unit of the installation, a damping device. Hereinafter, we will designate

  term of vibration, including vibrations of the structure

  different components, for example the damping device. The term displacement has a wider acceptance and is supposed to relate to the installation as a whole, and it must be understood that this is, apart from

  many components of vibration, also deformation

  such as brief deformations of an airplane cell during a flight.

  To meet the requirements mentioned above

  Today, we start from the fact that any movement within a complete system must be removed. Under

  the term complete system is here referred to as all the components

  individual components of the installation as well as the damping device. Such an overall system is described in the German patent application DE 26 26 469 A1. This overall system has a rigid work surface,

  which are connected the individual components of an instru-

  tallation. The work surface is rigidly connected to the rigid tubular frame and is connected again

  on the ground via damping elements.

  Depreciation therefore occurs exclusively

  in the damping elements.

  FIG. 4a shows by way of example the arrangement of a usual installation in connection with a damping device. For this purpose, a frame-shaped structure consists of profiled elements 40a to e. The various profiled elements 40a to 40e are welded together, or are screwed together by means of connecting elements not shown. Therefore, we

  obtains a structure in the form of a rigid frame. The structure

  ture-shaped frame is connected via

  connecting elements 41, for which it is also

  rigid connecting elements, either damping elements or damping elements, which are fixed by means of the corresponding receiving unit, by means of

  example in an airplane or in a vehicle.

  The individual components 43a to 43g, which cooperate with

  for example in a test structure or for the execution of measurements, are connected directly fixedly to a profiled part of the frame-like structure or are rigidly connected to this structure by means of mounting plates 44a. or 44b. Therefore, with the exception of linkages 41 which

  may be arranged in the form of damping

  it is a connection as rigid as possible of

all the elements.

  As shown for example in FIGS. 4b and 4c, an installation 43, which can be formed of different individual components, can also be connected via a mounting structure, which consists of profiled parts 45a and 45d, at a

  frame-shaped structure 40a to 40f. The different

  45a to 45d of the mounting structure are also welded or screwed in accordance with the

  frame 40a to 40f so that it is a rigid unit.

  As can be seen in Figure 4b and 4c, the elements

  41, which may be damping members

  can be arranged either between the structure of

  45a to 45d and the frame-like structure 40a to 40f or between the frame-like structure and said receiving unit 42, in which case the mounting structure 45a to 45d and the frame-like structure 40a to 40f are screwed together.

  firmly together by means of corrugated plates

liaison respondents 46.

  A disadvantage in the device described above

  of course lies in the fact that it is a

  completely rigid structure, in which disturbances

  tions, which appear, are damped only by connecting elements. Therefore vibrations and displacements, which are not amortized by these elements of

  linkage, are transmitted almost without being attenuated at

  components of the device. Relocation

  the resultant differences between the different components can, however, distort the results of

  as they become unusable.

  For example, twisting of the cell of an aircraft may not be absorbed by the connecting elements and consequently lead to a torsion of the

  frame-shaped structure. Consequently,

  relative appear between individual components

  duels rigidly connected to the frame-like structure.

  By providing a mounting structure 45a to 45d shown

  in FIGS. 4b and 4c, between the installation and the structure

  frame 40a to 40f, this effect can not be prevented. Another disadvantage of an arranged frame structure

  as described above, lies in the amor-

  weak internalization, since the different

  sections 40a to 40f are interconnected rigidly

  by means of welded links or links

  his opinion. Therefore structural vibrations, which appear in the frame-like structure, are not

  not amortized or only slightly amortized.

  To obtain the rigidity of the shaped structure

  framework, which is required in the usual principle of

  As regards the profiled parts, these should be relatively thick wall sections. This results in relatively high masses of inertia, which

  is also harmful during the occurrence of disturbance

tions.

  Therefore, the object of the invention is to create a device for eliminating relative displacements between individual components of an installation, in particular

  to suppress the transmission of vibrations,

  or other disturbances, as well as structural vibrations from the environment to another structure comprising several individual components, so that the mutual position of the individual components remains

approximately unchanged.

  This is achieved according to the invention by means of a device for suppressing relative displacements between components and an installation,

  with a rigid platform on which the components

  the said installation are mounted or connected rigidly

  to the latter, having a frame-like structure and a receiving unit, characterized in that the frame-like structure comprises profiled parts,

  which are interconnected through gush-

  assembling assemblies such that adjacent profiled parts are spaced from one another so that the frame-like structure is flexible and dampens

  vibrations, displacements and other disturbances.

  According to another characteristic of the invention, the profiled parts have two U-shaped folded sheet metal parts and two flat sheet metal parts, and that the two U-shaped folded sheet metal parts are interconnected by connecting means. through flat sheet metal parts to form a

closed composite assembly.

  According to another characteristic of the invention,

  the connecting means are rivets.

  According to another characteristic of the invention, between the platform and the frame-shaped structure are rigid connecting elements and on the receiving unit are vibration dampers, which

  again are connected via rigid elements

  linkages to the frame-shaped structure.

  According to another characteristic of the invention, all the individual components of the device are mounted directly on the rigid platform and are connected to the rigid platform via a very rigid secondary structure, with the aid of very rigid means of connection. According to another characteristic of the invention, the rigid platform is arranged in the form of a

sandwich structure.

  According to another characteristic of the invention, the U-shaped folded sheet metal parts and the flat sheet metal parts have a thickness of the order of 1.5 mm.

  and are formed of an aluminum alloy.

  According to another characteristic of the invention, the thickness of the platform approximately corresponds to

  at the depth of the riveted profiled parts.

  According to the invention, as regards the device used to suppress relative displacements between different components of an installation, it is a structure consisting of a rigid platform and

  of a non-rigid frame-shaped structure and consequently

  it is no longer a global structure

  as rigid as possible. The individual components of the

  are mounted directly on the rigid platform or are connected to the platform via a rigid secondary structure using rigid connecting elements. As a result, a connection as rigid as possible between the individual components is again obtained, but not with the reception units which are provided by

example in an airplane.

  The non-rigid frame-shaped structure according to

  the invention preferably comprises rectangular profiles

  which are formed by sheets joined by riveting and are hereinafter also referred to as

  shaped parts, and connecting plates, which are

  hereinafter referred to as assembly gussets. The sheet metal profiles are connected by means of the gussets

  assembly so that the sheet metal profiles

  sins are not abutting. According to the invention, therefore, a flexible frame-shaped structure is obtained.

  The rigid platform is connected through

  reception units which are also rigid in the structure

  frame and the latter is connected by means of damping elements to the receiving units

  for example in an airplane cell.

  A frame-shaped structure arranged in accordance

  The invention in the form of a riveted structure has internal degrees of freedom, which act in a dissipative manner and therefore produce an attenuation of vibrations. The frame-shaped structure, which therefore acts as an energy receiver, absorbs vibrations well as

  produces in it an intense internal damping. People

  Emerging turbulences, such as vibrations, are therefore almost completely eliminated in a very wide range of frequencies. In the solution according to the invention, these advantages are obtained by means of increasing the gradient concerning the strength and the rigidity from the reception units to the components of the installation. In the embodiment according to the invention of the frame-shaped structure, it is furthermore advantageous

  that the vibrations introduced vanish very rapidly

  Therefore, in general, larger amplitudes are not transmitted to the rigid platform. Another advantage of the frame-shaped structure made of a thin sheet is the significant saving in weight so that there is no mass of inertia

disruptive high.

  Since the different profiled parts are joined together by means of so-called assembly gussets, so that they

  do not touch each other, it does not appear between the parties

  No impulse transmission in the form of shock (caused by shocks between the profiled parts). This

  has a positive effect on the damping behavior

the device.

  In the context of the invention it is furthermore advantageous that the resistance of the platform to bending and torsion is greater than that of the frame-like structure. Consequently, under the effect of bends and twists that appear in the frame-like structure, the platform is certainly displaced, but is not

  not bent or twisted. Such movements of the platform

  rigid form do not, however, affect the indi-

  the latter are attached to the platform or rigidly connected to the platform so that even in

between the different components.

  As a platform, platforms can be used

  common commercial forms of the so-called honeycomb type, which have a nest type structure

  of bees. Such honeycomb structures have

  dent, in addition to the advantage that it is rigid components having a low weight, the additional advantage of achieving internal vibration damping.

  Other features and advantages of the pre-

  invention will emerge from the description given below.

  after making reference to the accompanying drawings, on

what:

  - Figure 1 is a representation in perspective

  tive, reproduced in part in the manner of an exploded view, of a preferred embodiment of a device for suppressing the relative displacement; FIGS. 2a and b show a view in

  lateral elevation and sectional view of a portion of the

  of a frame-like structure; - Figure 3a shows an exploded perspective view of a corner region of the frame-shaped structure; - Figures 4a to 4c show a perspective view of corresponding devices according to the state of the art; FIG. 5 represents a side elevational view of a test structure in which the device according to the invention is used; FIG. 6a represents an elevational view

  right side of a frame-like structure

  in the test structure; FIG. 6b shows a front view of the frame-like structure used in the test structure; FIG. 6c represents an elevational view

  left side of the frame-like structure used

  in the test structure; Figure 7a shows a right side elevational view of a platform attached to the frame-like structure with individual components of the test structure; Figure 7b shows a front view of a platform attached to the frame-like structure, with the individual components of the test structure; Figure 7c shows a left side elevational view of a platform of the frame-like structure, with the individual components of the test structure; FIGS. 8a to 8e show the time signal diagrams, which have been recorded at measurement points shown in FIG. 5, at a height of approximately 9500 m; FIGS. 9a to 9e represent a diagram of signals obtained from a transformation (FFT) of time signals, which were recorded at the measurement points represented in FIG. 5, at a height of approximately 9500 m in a frequency range from 0 to 2500 Hz; FIGS. 10a to 10e are signal diagrams obtained from a transformation (FFT) of time signals, which were recorded at measurement points shown in FIG. 5, at a height of approximately 9500 m in a frequency range from 0 to 100 Hz; FIGS. 11a to 11e are time signal diagrams, which have been recorded at measurement points, shown in FIG. 5, at a height of m; FIGS. 12a to 12e are signal diagrams obtained from a transformation (FFT) of time signals, which were recorded at measurement points shown in FIG. 5, at a height of 150 m in a range of frequencies from 0 to 2500 Hz; and

  FIGS. 13a to 13e show diagrams

  gram of signals obtained from a transformation (FFT) of time signals that have been recorded at measurement points shown in FIG.

  150 m in a frequency range from 0 to 100 Hz.

  Figure 1 shows a perspective representation of

  a preferred embodiment of a device for suppressing relative displacements. A parallelepipedal frame-like structure 100 of the device comprises profiled portions 1a-1d, 2a-2d and 3a-3d, which are provided along the outer edges and are connected by means of three respective assembly gussets 4 at the corner areas. The constitution of the profiled parts and their connection by means of the assembly gussets 4

  to form the frame structure of a parallel shape

  The elepiped 100 will be described below in detail

  with reference to FIGS. 2a and 2b and FIGS.

3a and 3b.

  A platform in itself rigid 6 is disposed in the frame-shaped structure 100 via

  rigid connecting elements 5. In the form of

  represented in Figure 1, four elements of connection

  5 are arranged in the shape of a U and dimensioned so that they laterally grip the longitudinal edges of the platform 6. The connecting elements 5 are fixed

  on the one hand to platform 6 and on the other hand to both

  upper profiles 3c and 3d, which extend in the longitudinal direction. This means that the platform 6 and the four connecting elements 5, fixed to this platform, are dimensioned such that they fill the interspace between the inner sides of the two profiled upper parts 3c and 3d of the

frame-shaped structure 100.

  Individual components, not shown in FIG. 1, of an installation or for example of a test structure are fixedly mounted on the rigid platform

  6. To obtain optimum damping characteristics,

  with the device according to the invention, the thickness of the platform 6 should preferably correspond approximately to that of the profiled parts of the

frame-shaped structure 100.

  To the lower profile portions 1b and 1d of the frame structure 100, which extend in the longitudinal direction, two rigid connecting elements 7, respectively, are connected in fixed manner, with the frame-like structure 100 is fixed at

  means of damping elements 8 to reception units

  9. The reception units 9 themselves are provided for

  in a displacement system, such as an airplane.

  Figures 2a and 2b show for example a side elevational view and a sectional view of a profiled portion of the frame-shaped structure. Since all the profiled portions 1a to 1d, 2a to 2d and 3a to 3d have in principle the same arrangement, there is shown in detail, by way of example, in FIGS.

  and 2b the structure of the profiled portion la.

  The profiled portion 1a consists of two flat sheets 10a and 10a 'and two U-shaped sheets 11a and 11a in section. The U-shaped plates 11a and 11a each have two flat surface elements 11a1 and 11a2 or 11a1 and 11a2, which are parallel and arranged opposite one another and, perpendicularly to these two surface elements, another flat surface element lla3 or 11a'3. The three flat surface elements 11a1, 11a2 and 11a3 or 11a1, 11a2 and 11a3 are interconnected respectively via surface elements 11a and 11a23 or 11a13 or 11a23. In addition, each of the U-shaped sheets 11a 'and 11a' has, opposite the flat surface members 11a and 11a, flat parallel end strips 11a and 11a or 11a and 4a respectively. 5, which are again connected by means of angled surface elements 11a and 11a24 or 11a 'and 1a', to the flat surface elements 11a1 and 11a2 or 11a1 and 11a2. The flat end portions lla4 and lla5 or

  lla'4 and lia'5, which are located in one plane, are

  in such a way that a lla45 or

  lia'45 remains free between these end parts.

  On the basis of the previously described arrangement of U-shaped laminations 11a or 11a, the latter

  can be made in a simple way from a material

  of a flat sheet metal, by means of corresponding devices

folds.

  As can be seen in FIG. 2b, the two U-shaped folded sheets 11a and 11a 'are arranged in such a way that the two openings lla45 and 11a'45 are mutually facing each other. The flat sheet 10a is connected by means of rivets 12 (see FIG. 2a) to the flat sheet elements 11a2 or 11a'2 so that the flat sheet 10a does not protrude into the bent surface elements.

  lla23 or lia'23. The flat sheet 10a ', which is provided in

  to the flat sheet O10a and is parallel to this

  It is connected to the surface elements 11a or 11a of U-shaped folded sheets 11a and 11a ', also by means of rivets 12 so that the flat sheet 11a' does not protrude into the surface elements. angled lla13 or 11a'13. FIGS. 3a and 3b show, for example, an angular zone of the frame-like structure 100 before assembly and in the finished state. Such an angular zone has profiled parts 3a, 3b and 2a, which are arranged in accordance with FIGS. 2a and 2b and which are interconnected via assembly gussets 4a to 4c by means of rivets 12 indicated by of the

cross (+).

  As can be seen in FIG. 3a, in the case of the profiled part 3b, its U-shaped plate 31b protrudes with respect to the flat lateral plates 30b and b 'as well as to the U-shaped plate 31b, on a determined length which corresponds approximately to the largest dimension of the profiled portion 2a approximately rectangular in cross section. On the contrary, the two U-shaped sheets 31a and 31a 'and the two flat sheets a and 30a' of the profiled part 3a as well as the U-shaped sheets 21a and 21a 'and the flat plates 20a and 20a' of the part 20a end respectively in a plane. To form the corner zone, shown in FIG. 3b, of a frame-like structure 100, the assembly gusset 4a is fixed, for example by means of rivets 12 to the flat plate 30a of the profiled part. 3a so that the points, designated A and B, the assembly gusset 4a and the profiled portion 3a are brought into recovery. The flat sheet 21a 'of the profiled part 2a is then fixed to the assembly gusset 4a fixed to the profiled part 3a, so that the points, designated C and D, of the assembly gusset 4a and of the profiled part 2a are brought into recovery. It should be taken into account that the upper end, in FIG. 3a, of the profiled part 2a only extends into the lower half, in FIG. 3a, of the profiled part 3a so that the sheet-shaped part U 31b of the profiled part 3b, which in FIG. 3a protrudes beyond the U-shaped bottom plate 31b 'of the profiled part 3b, is disposed above the profiled part 2a. The profiled parts 2a and 3b are for example interconnected again by means of a rivet via the assembly gusset 4b so that the points E and F of the gusset

  4b or the flat sheet 20a 'of the pro-

  spun 2a and the points G and H of the assembly gusset 4b or the profiled portion 3b are placed in overlap. The assembly gusset is then fixed again with the help of rivets to the profiled parts 3a and 3b.

is visible in Figure 3b.

  During assembly and binding of the parties

  In addition, it is important to ensure that the differences

  profiles do not touch each other, but there is a distance between them so that no impulse transmission can occur between

different shaped parts.

  Hereinafter, with reference to FIG. 5, FIGS. 6a to 6c and FIGS. 7a to 7c, a test structure will be described in which the device according to the invention is used. FIGS. 8a to 12c reproduce test results recorded or determined in different

measuring locations.

  In Figure 5, there is shown an elevational view of

  side view of the test structure to measure a mid-scale wind field of an aircraft. For this purpose, a correspondingly modified frame-shaped structure 50 is fixed via dampers 51 to a receiving unit 52 provided in the airframe (not shown in detail). The structure

  shaped frame 50 is rigidly connected to a platform

  form 53, on which are mounted in a fixed manner

  individual strengths 55a to 55d of the test structure. With regard to the components 55a to 55d, it is a question of

  example of a telescope, several mirrors.

  As can be seen in FIG. 5, the path 54 of the radiation, which is enhanced by a shade of light gray, extends for a long distance within the

  test device. Since, in order to obtain results

  speaking states, a high accuracy of measurement is required, the different components 55a to 55d should not be

  displaced from each other or must

  may be slightly displaced from each other, ie the path of the radiation may only

  in a minimal way from its set position. For the control of the device according to the invention,

  which must suppress the transmission of vibrations,

  similar disturbances and disturbances at the level of

  components 55a to 55d of the test structure, the

  measuring points Mi to M4 are provided in different

  devices. The measurement point Mi is provided on the reception unit 52 to absorb disturbances applied in the device. Measuring point M2 is provided on the attachment of a damping block 51 used

  as a shock absorber, on the frame-shaped structure 50.

  Another measuring point M3 is provided on one of the profiled portions of the frame-like structure 50; it is a measurement point located near the attachment of the platform 53 to the frame-like structure 50.

  M4 measuring point is located on the platform 53.

  In the right-hand part of FIG. 5, there is shown a frame-like structure 60 in the form of a so-called 19 "rack, which is used to receive operating devices, such as The frame-shaped structure 60 is

  connected directly, through buffered blocks

  61 to the receiving unit 52. Since the frame-like structure 60 in the form of a so-called 19 "rack is not damped by a device according to the invention, Reference numerals may be made at a measuring point M5, Figures 6a to 6c show, to illustrate the necessary modification, the frame structure 50 used to perform the test, in a side elevation view of 6a), in a front view (Figure 6b) and in a left side elevational view (Figure 6c).

  frame form 50, it is a riveted structure

  according to the invention and constituted by plates

  AlCuMg2 aluminum alloy, which have a thick

  1.5 mm. In the various views of the frame-like structure used 50, the position of the damping block 51 as well as the position of the connecting portions 56 which establish the connection with the

  platform 53 not shown in Figures 6a to 6c.

  Figures 7a to 7c are views, which correspond to

  tooth to the views of Figures 6a to 6c, of the shaped structure

  frame, in which the rigid platform 53 is fixed.

  With regard to the test structure described here, an optical plate of the XS series from the company Newport was chosen as the platform, which is arranged with the so-called honeycomb embodiment, so that of this

  a platform which, for great rigidity, pos-

  has a relatively low weight. As shown

  7b, the platform 53 is connected to the frame structure 50, via

four connecting elements 56.

  Because of the limited space, it was necessary to fix the lower connecting elements 56 with the same screws as those of the damping block 51 shown in Figure 7b. As a result, a direct link is established between the damping block 51 and the platform 53 so that

  direct transmission of disturbances of the damped blocks

  51 at platform 53 seems possible at least in

  part. The depreciation results, which can be obtained

  using the device according to the invention can be further improved when a complete decoupling of the

  platform 53 opposite the damper block 51 is pos-

  sible, and these elements are interconnected only by

  through the frame-shaped structure.

  As already mentioned, the components at 55d are fixedly mounted on the platform 53.

  considering the relatively important reciprocal distances

  between the different components 55a to 55d, which are visible in particular in FIGS. 7a and 7c, it can be seen that already small relative displacements between the various

* components would strongly distort the measurement results.

  In FIGS. 8 to 13, the

  measurement results obtained at the level of individual points

  measurement duels Mi to M5 (see Figure 5). At each measuring point, the vibration behavior was recorded with acceleration sensors in the direction of the X and Z axes

(see Figure 5).

  In FIGS. 8a to 8e, the time signals are represented in the case of a flight height of approximately 9500 m, at measurement points Mi to M5. The amplitude has been plotted on the ordinate respectively as a function of the acceleration of gravity [g] and on the abscissa the time in seconds [s]. In FIG. 8a it can be seen that in the reception unit 52 (FIG. 5) appear, in the X direction as well as in the Z direction, amplitudes which are in part greater than 0.4 times the acceleration of gravity. . In Figure 8b we see that a net reduction

  amplitude already occurs directly downstream of

  Damping elements 51 (Figure 5). However, these are still amplitudes of up to one tenth

  the acceleration of gravity [g].

  At the measurement location M3 shown in FIG. 8c, the amplitude decreases in the direction of the X axis, but especially in the direction of the Z axis with respect to the measurement location M2. Therefore already from there, the damping action of the structure in the form of

frame is visible.

  The measured values shown in Figure 8d and taken at the M4 measuring point, which is located on the

  platform 53 (see Figure 5), show clearly, over-

  by comparison with the measured values shown in Figure 8a, the magnitude of the amplitudes has greatly decreased. Comparative measurements, illustrated on the

  Figure 8e and executed at the measuring point M5

  In addition, the substantially better damping characteristics of the device according to the invention are compared to a frame-like structure in the form of a rack.

of 19 ".

  FIGS. 9a to 9e show the signals formed by the fast Fourier transforms (FFT) of the time signals represented in FIGS.

  at 8th for a flight height of about 9500 m. We have

  the amplitudes as a function of the gravitational acceleration [g] and on the abscissa the frequencies in Hz are represented in a range from 0 to

  2500 Hz. The measurement results, already explained in

  FIGS. 8a to 8e are shown in addition

  by means of frequency representations. If we compare

  particularly in FIGS. 9a and 9d, it is clearly seen that, starting from a frequency of 500 Hz and in particular from a frequency of 1000 Hz, the high amplitudes, which appear at the measurement point M1, are almost completely fainted. Therefore we see that

  high amplitudes, which appear in the reception unit

  52 (Figure 5), are very strongly damped by the device according to the invention and therefore are not transmitted to the platform 53 (in Figure 5), nor the components 55a to 55d mounted on the platform 53. Measured values, which are shown in Figure 9e and are obtained at the point of measurement

  M5 is located on the bay at 19 "60 (Figure 5), confirming

  again the intense damping effect of vibra-

  tions, that allows the device according to the invention.

  FIGS. 10a to 10e show the measurements, which are shown in FIGS. 9a to 9e, for a frequency range from 0 to 100 Hz. From the measurement values, it can be seen that frequencies in a range up to at 100 Hz are not damped by the device according to the invention. However, since these are relatively low frequencies, the effects on the measurement accuracy of the components 55a to 55d provided on the platform 53 are only of secondary importance, especially since the platform 53 is only moves, but is not twisted, at low frequencies. Consequently, there is no relative displacement between the different

components 55a to 55d.

  In another series of tests, the same measurements were taken at the same height as 150 m for the previously described measurements and carried out at a flight height of about 9500 m. The measurement results obtained are

  reproduced in FIGS. 11 to 13.

  A comparison of FIGS. 11a to 11c with FIGS. 8a to 8e shows that, for a flight height of m much lower than a flight height of about

  9500 m, the excitations applied to the system are clearly

  weaker. It can be seen in FIGS. 12a to 12d that the amplitudes, which appear in higher frequency ranges, of the device according to the invention are

  almost completely eliminated (see Figures 9a to 9d).

  In the case of flying at a low height, as can be seen in FIGS. 13a to 13e, it is often striking that high amplitudes, which can not be damped by the device according to the invention, appear in ranges. lower frequencies. Since in the case of these amplitudes which subsist in

  the system, these are amplitudes obtained at low frequencies

  quences, these amplitudes do not affect the execution of the measurements using the components 55a to 55d which are mounted

  on the platform 53. This is because the amplifiers

  studies, which occur at low frequencies, trigger a shift, but not a deflection or a torsion of

  platform 53. Therefore, the entire platform

  form 53 is usually displaced, but the components indi-

  viduals 55a to 55d perform no relative movement.

  From the amplification, visible in FIGS. 13a to 13d, from the amplitude of the application to the reception unit 52 up to the platform 53, it can be concluded that these are frequencies of resonance

  damping blocks 51. These disturbances may therefore

  can be reduced through the use of other depreciation

Claims (8)

  1. Device for removing displacements   between components of an installation,   a rigid platform (6), on which the components   sants (55a to 55d) of said installation are mounted or   rigidly connected to the latter, comprising a structure   frame-shaped frame (100) and a receiving unit (9), characterized in that the frame-like structure (100) has profiled portions (1a-1d, 2a-2d, 3a-3d),   which are interconnected through gush-   assembling sets (4) so that the parts benefit   adjacent ones (1a to 2d to 2d, 3a to 3d) are spaced from each other so that the frame-like structure (100) is flexible and dampens vibrations,   displacements and other disturbances.   2. Device according to claim 1, characterized   in that the profiled parts (la) have two U-shaped folded sheet metal portions (11a; 11a) and two flat sheet metal parts (10a, 10a ') and that the two folded sheet metal parts U (10a, 10a ') are interconnected by connecting means (12) via flat sheet metal portions (10a, 10a') for   form a closed composite assembly.   3. Device according to claim 1 or 2, characterized in that the connecting means are rivets (12).   4. Device according to any one of the   1 to 3, characterized in that between the platform (6) and the frame-like structure (100) rigid connecting elements (5) are provided and that on the receiving unit (9) are arranged vibration dampers   (8), which are again connected via   rigid connections (7) to the structure in the form of frame (100).   5. Device according to any one of the   cations 1 to 4, characterized in that all components   devices (55a to 55d) of the device are mounted directly   on the rigid platform and are connected to the platform   rigid form (6) via a secondary structure   very rigid, using very rigid means of connection.   6. Device according to any one of the   cations 1 to 5, characterized in that the rigid platform   (6) is arranged in the form of a sandwich structure.   7. Device according to any one of the   1 to 6, characterized in that the U-shaped folded sheet metal parts (11a, 11a ') and the flat sheet metal parts (10a, 10a') have a thickness in the range of   1.5 mm and are formed of an aluminum alloy (AlCuMg2).   8. Device according to any one of the   cations 1 to 7, characterized in that the thickness of the   platform (6) corresponds approximately to the depth   riveted profiled parts (la to ld; 2a to 2d; 3a to 3d).