WO2017174325A1

WO2017174325A1 - Shielding part having a fastening device for fastening the shielding part to a fastening partner part

Info

Publication number: WO2017174325A1
Application number: PCT/EP2017/056277
Authority: WO
Inventors: Gerald Heiselbetz
Original assignee: Elringklinger Ag
Priority date: 2016-04-05
Filing date: 2017-03-16
Publication date: 2017-10-12
Also published as: DE102016106153A1

Abstract

The invention relates to a shielding part, especially a thermal shield having a fastening device (4) for fastening the shielding part (1) to a fastening partner part (2).

Description

SHIELDING PART WITH A FASTENING DEVICE FOR ATTACHING THE SHIELDING PART TO A FASTENING PARTNER

The invention relates to a shielding part, in particular a hit ^¬ zeschild with a fastening device for fastening the shielding member to a mounting partner part according to the upper ^¬ concept of claim 1.

From EP 1 548 246 A2 a shielding part is known, which has a fastening device, wherein the attachment ^¬ device has a collar sleeve and the collar sleeve are coupled via bridging elements, which interact with outsides of the Abschirm ^¬ part, with the shielding. The collar sleeve is slidably mounted in a radial direction with respect to the shielding, so that between the collar sleeve and the hole edge of the shielding a game is present. Is in such a shielding member in an operating Situational ^¬ tion the collar sleeve reached with respect to the hole edge in the region of maximum displaceability within the hole in the shield ^¬ part, it may happen that a hole edge of the Lo ^¬ ches collides in the shielding member to the sleeve body and, from this ^¬ special when vibrations are added, unwanted noise occurs.

The object of the invention is therefore to develop the shielding such that even with a maximum possible displacement of the sleeve relative to the hole recess of the shielding unwanted noise is avoided. Furthermore, a shielding is to be provided with a fastening device for the shield, which makes the desired Ge ^¬ räuschreduzierung realized with simple means. This object is achieved with a shielding with the features of claim 1. Advantageous embodiments are specified in the subclaims.

A shielding member according to the invention is in particular designed as a ^heat shield and has a fastening device for fastening of the shielding member to an attachment partner member such. As a turbocharger, an exhaust manifold or the like, wherein the fastening device comprises listed below components: a collar sleeve with a through hole for a fastener, wherein the collar sleeve has a sleeve ^¬ body, spaced from the two in a radial direction R in an axial direction A to each other frets depart radially outwardly, wherein the collars in the axial direction a between them define a gap and the sleeve body is s is ^¬ arranged in a recess of the shielding member with a radial clearance relative to egg ^¬ nem hole edge of the recess of the shielding,

at least two bridging elements, which ^abut with ra ^¬ dial outer regions on opposite outer sides of the shielding directly or indirectly and are arranged with radially inner regions in the intermediate space and are penetrated by the sleeve body

Such shielding is inventively labeled in ^¬ characterized in that in the radial direction R between a hole edge of the recess of the shielding member and the sleeve body and in the axial direction A between the collars at least one damping element is arranged that the radial clearance s of the sleeve Body limited to the edge of the hole on an effective radial clearance s' decreasing.

According to the invention, a buffer member is provided thus, wel ^¬ ches is arranged between the shield member and the sleeve, that a direct radial clash of the sleeve is prevented on the hole edge of the shield. The Dämp ^¬ tion element is adapted and designed to produce in a collision between the damping element and the hole edge of the shielding or alternatively in a collision between the damping element and the sleeve body no unwanted noise.

In a preferred embodiment, this is the damping element in comparison to the sleeve body and / or compared to the hole edge of the shielding deformation-soft. In particular, the damping element in comparison to that component with which a collision threatens or ma ^¬ ximaler displacement of the collar sleeve relative to the shielding is conceivable, formed deformable soft. The Dämpfungsele ^¬ ment is formed in particular at least in a contact region between the damping element and the shielding or in ei ^¬ nem contact area between the damping element and the sleeve body with respect to the corresponding contact partner parts deformation soft.

The abovementioned measures make it possible to effectively form the damping element as a soft buffer element, which exhibits little or no noise even in the event of a collision with adjacent components.

In a preferred embodiment, the damping element is a wire mesh, a wire tangle, a Drahtgewirk, a

Wire mesh or a wire mesh of a metal wire. A Such training is in particular at a high Tempe- raturniveau, as may occur in particular in the field of exhaust systems in question.

As an alternative to a metal wire, the damping element may also be formed of a plastic wire, when this is permitted by the Tem ^¬ peraturbedingungen.

Next alternatively comes into question that the damping element is designed as a metal or plastic foam.

In a further embodiment, the damping element surrounds the sleeve body like a ring radially free of play. In a derar ^¬ term embodiment, the composite of sleeve, bridging elements and damping element is moved together relative to the shielding, when it comes to an offset between the shielding and the fastening device, in particular due to thermal expansion or vibration. Thus, the relative movement between the collar sleeve and the shielding part takes place exclusively in a contact region between the bridging elements and the outer sides of the shielding part. In addition, it is advantageous that the damping ^element can be made small in terms of its outer diameter and thus requires a relatively small amount of material.

As an alternative to the aforementioned embodiment, it may also be expedient that the damping element bezüg ^¬ Lich of the hole edge of the shield at the edge of the hole is arranged From ^¬ shield part radially free of play. In this embodiment, the damping element is stationary with respect to a displacement of the sleeve in the radi ^¬ alrichtung with respect to the hole edge and thus bezüg ^¬ Lich arranged the shielding. It does not have to be moved together with the sleeve relative to the shielding. In such an embodiment, the damping element can already be fastened to the shielding part before the mounting device is mounted. For the assembly of the fastening ^¬ device is then only necessary to mount the bridging elements and the collar sleeve. This can be a simplification in the assembly process.

In a further embodiment, the damping element is dimensioned such that the effective radial clearance s' is greater than or equal to 0 mm. As long as the effective radial clearance s' is greater than 0 mm, the collar sleeve can be moved relative to the shielding in the manner of a sliding seat in the radial direction R. But depending on the application, it may also be useful, the effective radial clearance s' of the sleeve relative to the shielding means of the damping element to 0 to reduzie ^¬ ren. A displacement of the collar sleeve inside the recess of the shielding member so that only the Dämp ^¬ Fung element possible under deformation. This may be useful in particular for tuning and influencing the vibration characteristic of the shielding together with the fastening device.

To avoid unwanted rattling noise due to a relative movement between the shielding and the collar sleeve in the axial direction A, it is expedient that the Dämp ^¬ tion element axially biased in the space between the collars, in particular between the bridging elements is arranged.

An another embodiment, the Überbrückungsele- elements advantageously are formed as a spring, which may be more preferably formed as stamp-bent or punched-drawn parts into ^¬ particular from a spring steel sheet, and the like. It is also expedient, optionally a ^¬ parts form the collar sleeve from a sleeve body and integrally from the sleeve body outgoing frets. Alternatively to the above embodiment, it is also expedient to form the collar sleeve from egg ^¬ nem first part and a second part, wherein the first part of the sleeve body and one of the frets integrally formed and the second part is disc-shaped and the two ^¬ th fret of Forms collar sleeve.

In the following the invention will be described by way of example with reference to the drawing. Show it:

Figure 1: a first embodiment of an inventive

Shielding strongly schematized in a cross ^{¬ section} by a fastening device of the shielding.

Figure 2: a second embodiment of an inventive

The embodiments according to FIGS. 1 and 2 are sectional views in which dimensions of certain components are given below as diameters. By this indication, the invention is by no means limited to circular in a plan view components with a same diameter in each radial direction. Rather, the spatial forms can deviate in a different than the drawing sectional plane shown.

An inventive shielding 1 is as a sheet Blechla ^¬ ge, z. B. formed of an aluminum sheet or a steel sheet. The shielding part 1 can be formed in the usual way one or more layers. It can also have non-metallic insulating layers to ensure, for example, an acoustic insulation can. Such shielding come, for example, to shield heat from hot components, such. As turbochargers, exhaust systems, exhaust manifolds or the like in motor vehicle construction are used. The main purpose of such shielding parts is to shield heat-sensitive components from heat radiated from a hot component. Nonetheless, usually shielding parts 1, where they are used in motor vehicle construction, also have sound-absorbing functions.

Such shielding 1 can both directly to the heat-emitting component ^¬ , z. B. on the exhaust manifold, or attached to the turbocharger. However, it is to fix possible such From ^¬ screen parts to the components to be protected. In particular, it is often expedient to fasten such Abschirmtei ^¬ le 2 to body parts. In general, therefore, a component to which the shielding member 1 is to be attached will be referred to as a fastening partner member 2 hereinafter. The fastening partner part 2 has, for example, a thread 3 into which a screw (not shown) can be screwed in acting as a fastening means.

The shielding member 1 has a fastening device for fastening on the mounting part 2 ^¬ partner 4. Fixed To ^¬ constriction device 4 has a collar sleeve 5 with a through hole 6 through which a connecting means, for. B. a screw (not shown), can be pushed through. In the installed state of the shielding part 1, the collar sleeve 5 is customary ^¬ the attachment partner part 2 to the plant and is fixed there. The collar sleeve 5 has a sleeve body 7, which is for example rotationally symmetrical about a central axis M formed ^¬ . The sleeve body 7 has a Außendurchmes ^¬ ser D _H. From the sleeve body 7 go in an axial direction A a first collar 8 and a second collar 9 in a radial direction R radially outward. An axial distance between the first collar 8 and the second collar 9 is designated by a.

For the production of an operative connection between the collar sleeve 5 and the shielding member 1 is a bridging member 10 see pre ^¬. The bridging element 10 is formed in the illustrated embodiments according to Figures 1 and 2 of two spring layers, a first spring layer 10a and a second spring layer 10b. Both the first spring layer 10a and the second spring layer 10b have a radially outer region 11. In the radially outer region 11, the first spring layer 10a is set against a first outer side 12a of the shielding part. The two ^¬ th spring layer 10b is set in its radially outer region 11 against an opposite to the first outer side 12a outside 12b of the shielding.

With the bridging element 10, consisting of the first Fe ^¬ derlage 10 a and the second spring layer 10 b, the collar sleeve 5 is held in a recess 13 of the shielding part 1. The off ^¬ recess 13 is for example a circular hole and has a diameter D. The recess 13 has a hole edge 14. Radially outside of the hole edge 14, a Reversed closes ^¬ bung portion 15 of the hole edge 14 at. Within the ambient ^¬ portion 15, the spring layers are supported 10a and 10b in a radial ^¬ direction R relative to the shield 1 by overcoming frictional forces between the radially outer portion 11 of the spring layers 10a, 10b and the outer sides 12a, 12b in the radial direction R displaceable. In this case, the surrounding region 15 is sufficiently sized so as it extends in the radial direction R, that a required displaceability its mountings ^¬ constriction device 4 is relatively ensured to shield 1 sufficiently. The first spring layer 10a and the second spring layer 10b, ie the bridging element 10, also have a radially inner region 16. The spring layers 10a, 10b are located with their radially inner region 16 within a gap 17, which in the axial direction A through the first collar. 8 and the second collar 9 is limited. In the radial direction R of the intermediate space 17 is radially inwardly limited by the sleeve body 7. In the radial direction R to the outside of the gap 17 is not limited by components of the collar sleeve 5. The Zvi ^¬ c region 17 terminates radially outwardly expediently at radially outer end edges 8b, 9b of the collars 8, 9. The radially inner portions 16 of the spring layers 10a and 10b are in particular in the axial direction A spring-biased against inner surfaces 8a, 9a of the first collar 8 and second Federal 9 set.

The spring layers 10a, 10b, that is, in its entirety, the Überbrü ^¬ ckungselement 10 are disposed radially without clearance or with little Ra ^¬ dialspiel the sleeve body 7 surrounding. Under gerin ^¬ gem game is understood in this case, a game of a few hundredths or a few tenths of a millimeter, which is to provide for manufacturing reasons, to ensure easy, aufsteckendes joining the spring layers 10a, 10b on the sleeve body 7. The game is chosen such that a loose clearance but no significant relative ^¬ movement between the sleeve body 7 and the bridging element is possible. The radial displaceability of the collar sleeve 5 with respect to the shielding part 1 is - as already erläu ^¬ tert - provided by providing a sliding sliding seat and overcoming frictional forces in the region of the radially outer portion 11 of the bridging element 10, ie the spring layers 10a, 10b, which in the radially outer region 11 in the radial direction R relative to the shielding part 1, in particular its outer sides 12a, 12b, move radially. With the prescribed arrangement, the fastening device 4 is held fixed relative to the shielding part 1.

In the above-described arrangement, there is a theoretical radial clearance s between the sleeve body 7 and the hole edge 14, which is composed of the diameters D and D _H

s = D - D _H

results.

To reduce this theoretically possible radial clearance s sitting according to the invention in the intermediate space 17, a damping element 18, which in the embodiment of Figure 1 without play o- almost without play rests on the sleeve body 7. The damping ^¬ element 18 has an outer diameter D _A , which is smaller in the embodiment of Figure 1 as the diameter D of the recess 13. The damping element 18 is due to ^¬ NES backlash-free or virtually backlash radial seat relative to the sleeve body 7 with the collar sleeve 5 in the radial direction R formed mitbewegbar. In the embodiment of Figure 1 thus form the collar sleeve 5, the first spring layer 10a, the second spring layer 10b, ie the bridging element 10 and the damping element 18, which are not zueinan ^¬ each other except for an un ^¬ avoidable mounting clearance in the radial direction R, the fastening device 4, which as a whole is held displaceably in the radial direction R relative to the shielding part 1, the relative movement taking place between the radially outer region 11 of the spring layers 10a, 10b and the outer sides 12a, 12b of the shielding part.

By the provision of the damping element 18 with its outer diameter D ^¬ _A theoretical radial clearance is s 'is reduced, whereby the effective radial clearance s' on an ef ^¬ fektives radial clearance to s S '= D - D _A

results. The outer diameter D _A is selected to the diameter D such that a sliding fit of the fastening device 4 within the game s' is dimensioned sufficiently large, so occurring during operation, relative movements between the shielding part 1 and the fastening device 4, fixed fixed to the mounting part 2 is, can be compensated. Such shifts can occur, for example, due to thermal expansions of the shielding part 1, since the shielding part 1 is usually fastened to the fastening ^partner part 2 by a plurality of fastening ^devices . Heating and cooling of the shielding part 1 causes thermal expansions which can be compensated for in the sliding fit between the fastening device 4 according to the invention and the shielding part 1.

The damping element 18 differs from the übri ^¬ gen components (collar sleeve 5, bridging member 10 and Ab ^¬ screen part 1) essentially in that, relative to said components, in particular at least in a contact ^¬ area 20 which with the edge of the hole 14 in it a maximum possible ^¬ union displacement of the attachment device 4 relative to the shielding member 1 can come into contact, verformungswei ^¬ cher is formed. By providing such, compared to a possible contact component deformation-softening damping element 18, it is possible in contact a crash o- a contacting of the damping element 18 with the hole edge of the shielding 1 (embodiment of Figure 1) with respect to an impact noise to make much quieter or silent. The damping element 18 acts as a noise-damping buffer element.

Conveniently, the damping element 18 is made of a wire structure, in particular a steel wire structure, for example example, a wire mesh, a wire ^tangle , a Drahtgewe ^¬ be, a knitted wire or a Drahtgewirke formed. In such a formed damping element 18, although the material of the wire, for example a steel wire itself is not necessarily deformation-soft than a component such. B. the shielding part 1, but is seen by a loose or loose arrangement of the wire in the form of a compressed wire mesh, wire tangle or wire mesh and where appropriate ^¬ a wire mesh or a wire knit the damping element 18 seen as a whole body deformed ^¬ cher than, for example, the shielding part 1, with the hole edge 14, the damping element 18 may come into contact in an extreme position. In that regard, the term "deformation ^¬ softer" is to be understood in that at least in the ge ^¬ called contact area 20, the damping element 18 is formed ^¬ such that it is designed as a total body at least in Kontaktbe ^¬ rich 20 compliant, ie deformation soft than a partner part , For example, the shielding part 1, with which it gets in contact area 20 in contact.

As an alternative to the above-described embodiment as a wireform, the damping element 18 may be meaningfully formed from a metal foam. In areas with lower temperature load of the shielding member 1, it may optionally also be expedient to form the damping element 18 made of a synthetic material ^¬ wire fabric, a plastic fiber structure or a plastic foam.

In the embodiment of Figure 1, the effective Radi ^¬ alspiel s 'is greater than 0 mm formed so that the Fixed To ^¬ constriction device 4 relative to the shielding member 1 via a sliding fit within the effective radial clearance s' has. If, in the case of a shielding part according to the invention, one or more fastening devices 4 do not require a sliding fit relative to the shielding part 1, then the outside diameter D _{A of} the damping element 18 can also be selected such that it is equal to the outside diameter D of the recess 13 in the shielding part 1. This results a play-free or almost play-free fit of the fastening device 4 within the recess 13 of the shield 1. The damping element 18 acts due to its design as a damping wire structure or noise damping due to its design as a damping foam structure, for example, due to radial vibrations of the shielding 1 a knocking contact between the Hole edge of the recess 13 and the contact area 20 would arise during operation of the shielding.

In the axial direction A, the damping element 18 may also be pre-tensioned in the intermediate space 17 ^¬ sitting, and thus the spring layers 10a, 10b in the radially inner region supporting against the inner sides 8a, 9a of the collars 8, press. 9 The Dämpfungsele ^¬ ment 18 can thus ensure in a simple manner by its arrangement in the intermediate space 17 and an effective axial bias of the bridging element 10 with respect to the collar sleeve 5 and act as a spacer.

The collar sleeve 5 is formed in the embodiment of Figure 1 from a first part 5a and a second disc-shaped component 5b. The first part 5a forms the sleeve body 7 and the second collar 9. The disc-shaped second part 5b form the first collar 8 and is connected in a known manner with the first part 5a.

Of course, it is also possible to form the collar sleeve 5 in one piece or form of more than two parts. In the inventive shielding member 1, the Fixed To ^¬ constriction device comprising 4 is of particular advantage that the damping element 18 is seated in a closed space, so that ei ^¬ ne contamination or entry of cross contamination in the pores of the damping element, if it for example, as a wire structure or a foam structure is formed, is ver ^¬ prevented.

The space in which the damping element sits dirty, is limited in the axial direction A by the spring layers 10a, 10b. Radially inside this space is limited by the sleeve body 7. Radially outside the space is limited by the first Federla ^¬ ge 10a, the second spring layer 10b and the hole edge 14 of the Ab ^¬ screen part 1. For this purpose, it is particularly expedient to design the spring layers 10a, 10b as elements which are closed in a circumferential direction U and essentially disc-shaped in a plan view. The spring layers 10a, 10b are in be ^¬ particularly preferably formed of a stainless steel, in particular a spring steel and preferably have a thin wall thickness, in particular in the range between 0.2 mm and 0.5 mm.

Next, a second execution ^¬ shape of the shielding member 1 of the invention will be explained with reference to FIG. 2 The second embodiment of the shielding part 1 according to the invention has a similar basic structure as the previously described first embodiment according to Figure 1, so that the same components are provided with the same reference numerals. With the exception of the differences described below, the statements made for the embodiment according to FIG. 1 also apply to the embodiment according to FIG. 2.

An essential difference of the embodiment according to FIG. 2 compared to the embodiment according to FIG. 1 is that the Damping element 18 has an outer diameter D _A , which corresponds to the diameter D of the recess 13 in the shielding part 1, so that the damping element 18 seated free play or almost play ^¬ free or biased in the radial direction R in the recess 13.

In order to provide a sliding fit of the collar sleeve 5 relative to the recess 13 of the shielding part 1, the damping element 18 has an inner diameter Di which is greater than the outer diameter D _{H of} the sleeve body 7. Thus, the effective radial clearance s' in the embodiment according to FIG 2 between the damping element 18 and the sleeve body 7 gebil ^¬ det and results

The collar sleeve 5 is in this embodiment, together with the sleeve body 7 backlash or almost backlash ^¬ umbending ^¬ bridging element 10, consisting of the first Fe ^¬ derlage 10 a and the second spring layer 10 b relative to the damping element 18 within the effective radial clearance s' ver ^¬ displaceably arranged , The damping element 18 is seated radially fixed in the recess 13 of the shielding part 1, so that the Fe ^¬ derlagen 10 a, 10 b abut in the radial direction R on the damping element 18 and radially relative to the damping element 18 are ver ^¬ displaceable. In this embodiment, therefore, with a relative change in position of the collar sleeve 5 relative to the shielding member 1 is a sliding contact between the spring layers 10a, 10b and the damping element 18 and between the radially outer portion 11 of the spring layers 10a, 10b and the shielding part 1 and its outer sides 12a, 12b instead.

In this embodiment, it is advantageous that the contact area 20 of the damping element 18 extends over almost the GESAM ^¬ te axial height a of the clearance 17th The contact- Area 20 acts in the case of a maximum displacement of the collar sleeve 5 in the radial direction R with an outer side 21 of the collar sleeve 5, respectively, of the sleeve body 7 together.

Although the above-described embodiments according to Figure 1 and Figure 2, which are shown as sectional views, for the case of circular recesses 13 and circular outer / inner diameters D _A , Di, D are described, it is of course within the scope of the invention, for example the recess 13 in a certain radial direction R form as a slot, so that the effective radial clearance s' in this direction may be greater than in another radial direction R. Also, it may be appropriate, the diameter D _A not over the entire circumferential direction U constant to keep. The outer diameter D _{A of} the damping element 18 may have a different value in a radial direction R than the radial direction R shown in the sectional view according to FIGS. 1 and 2. So z. B. by a suitable choice of the diameter D, D _A and D and Di, the fastening device 4 in a radial direction R be held without play in the shielding 1 and have in another radial direction R an effective radial clearance s'> 0.

Claims

claims

Shielding part, in particular heat shield with a

Fastening device (10) for fastening the

Shielding member (10) on a mounting partner part (12), the fastening device comprising:

a collar sleeve (12) having a through hole (10) for a fastener (10), the collar sleeve (12) having a sleeve body (12) from which radially in a radial direction R two collars (12) spaced apart in an axial direction A extend radially outwardly, the collars () defining therebetween a clearance (14) and the sleeve body (12) is disposed in a recess (12) of the shielding member (12) with a radial play (s) relative to a hole edge (12) of a recess (12) of the shielding member (12); at least two bridging elements (12); ) which radially or indirectly abut the collars (12) on opposite outer sides (12) of the shielding member (12) and are arranged with radially inner portions (12) in the space (12) and are penetrated by the sleeve body (10),

characterized in that

in the clearance (12) in a radial direction (R) between a hole edge (16) of the recess (12) of the shielding member (12) and the sleeve body (10) and in

Axial direction (A) between the collar ()

Damping element () is arranged, which reduces the radial clearance (s) of the collar sleeve () relative to the shielding part () to an effective radial clearance s ^' limiting.

Shielding part according to claim 1, characterized in that the damping element (10) in comparison to Shielding () and compared to the collar sleeve () or in comparison to the sleeve body () is formed soft deformation.

3. Shielding part according to claim 1 or 2, characterized

characterized in that the damping element () a

Wire mesh, wire tangle or wire mesh is made of a metal wire or a plastic wire or is formed of a metal or plastic foam.

4. shielding part according to one of the preceding claims, characterized in that the damping element () surrounds the sleeve body () radially clearance.

5. Shielding part according to one of claims 1 to 4, characterized in that the damping element () is disposed radially backlash-free with respect to the hole edge () of the Abschirmteils () at the hole edge () of the Abschirmteils ().

6. shielding part according to one of the preceding claims, characterized in that the effective radial clearance s' is greater than or equal to zero.

7. shielding part according to one of claims 1 to 5, characterized in that the damping element () is disposed radially clearance between the hole edge () of the recess () of the Abschirmteils () and the sleeve body (), so that the effective radial clearance (s' ) is zero.

8. shielding part according to one of the preceding claims, characterized in that the damping element () is axially biased in the intermediate space ().

9. Shielding part according to one of the preceding claims, characterized in that the damping element () retaining collars () has, which extend radially outwardly beyond the hole edge () of the recess () in the shielding () addition.

10. shielding part according to one of the preceding claims, characterized in that between radially outer regions () of the bridging elements () and the

Outside () of the shielding () at least one

Sliding layer () is arranged so that the radially outer regions () indirectly via the sliding layer () to the

Outer sides () abut.

11. shielding part according to one of the preceding claims, characterized in that the bridging elements () are spring layers, in particular from a

Spring steel sheet, in particular as a punched bend or

Stamped drawing part are formed.

12. shielding part according to one of the preceding claims, characterized in that the collar sleeve ()

in one piece from a sleeve body () and integrally from the sleeve body () outgoing collars is formed.

13. Shielding part according to one of the preceding claims, characterized in that the collar sleeve () of a first part () and a second part () is formed, wherein the first part () the sleeve body () and one of the collars () integrally formed and the second part is disc-shaped and forms the second collar (12) of the collar sleeve (12), the second part (16) and the first part (16) being joined together. Shielding part according to one of the preceding claims, characterized in that the collar sleeve () has a cross-sectionally multi-layered sleeve body (10) and the damping element (12) is arranged between the outermost layer of the sleeve body (12) and the hole edge (11) of the shielding part.