CN209833551U

CN209833551U - Sound-absorbing component for a motor vehicle and structure for a motor vehicle

Info

Publication number: CN209833551U
Application number: CN201920240129.8U
Authority: CN
Inventors: 塞巴斯蒂安·奥利维耶
Original assignee: Virginia Automotive Industry Corp
Current assignee: Virginia Automotive Industry Corp
Priority date: 2018-02-28
Filing date: 2019-02-25
Publication date: 2019-12-24
Anticipated expiration: 2029-02-25
Also published as: FR3078299B1; FR3078299A1

Abstract

The utility model relates to a part and be used for structure of motor vehicle's sound absorption for motor vehicle's sound absorption part (10) are formed by first expanded plastic material (12), the part includes basic part (14) of injecing the internal cavity. The component further comprises a lid (18) and a hinge (20) hinging the lid to the base; the cover is capable of being assembled with the base in the closed configuration of the components. The base, lid and hinge portions being formed in one piece, the hinge portion (20) being formed from a flexible strip of a first expanded plastics material (12); the first expanded plastic material has a first density at the base (14) and a second density greater than the first density at the hinge.

Description

Sound-absorbing component for a motor vehicle and structure for a motor vehicle

Technical Field

The present invention relates to a component for sound absorption of a motor vehicle and a structure for a motor vehicle, said component being formed of a first expanded plastic material, comprising a base portion defining an internal cavity, said base portion comprising at least one first wall and at least one second wall facing each other.

Background

It is known, for example, from document EP 1693255 to equip a motor vehicle with a sound-absorbing element made of expanded plastic material. It is also known, for example from document FR3026080, to equip the structure of a motor vehicle (for example the floor of the vehicle) with a compartment containing sound-insulating material.

The volume of the sound-absorbing element represents an additional weight for the vehicle. However, for reasons of mechanical stress and acoustic performance, the material of the element needs to have a density above a certain threshold.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to propose a part of sound absorption of weight reduction, keep sufficient rigidity and good acoustic performance simultaneously.

To this end, the invention relates to a sound-absorbing component of the aforementioned type, which further comprises a cover and a fold hinging said cover to the first wall of the base; the cover can be assembled with the second wall in the closed configuration of the parts. The base, lid and hinge are formed in one piece, the hinge being formed by a flexible strip of a first expanded plastics material. The first expanded plastic material has a first density at the base and a second density greater than the first density at the hinge.

According to other advantageous aspects of the invention, the means of sound absorption comprise one or more of the following features, which can be adopted alone or according to any possible technical combination thereof:

the first expanded plastic material comprises a thermoplastic polymer, preferably selected from polyethylene, polypropylene and polystyrene;

the component is configured such that in the closed configuration the internal cavity forms a volume closed by the cover;

the component is configured so that the base defines two internal cavities, the component further comprising two covers, each of which is hinged to the base by a different hinge.

The utility model discloses still relate to a structure for motor vehicle, it includes: at least one sound absorbing component as described above in a closed configuration; and a second plastic material overmolded on the at least one component.

Advantageously, the second plastic material comprises polyurethane.

The present invention also relates to a method for manufacturing a sound-absorbing component as described above, said method comprising the following steps: providing a die comprising a first portion and a second portion movable relative to each other between an open configuration and a closed configuration, the first portion comprising a blade forming an upper ridge, the second portion comprising a movable slide, the slide comprising a lower surface; depositing granules of a first plastic material in the mould in an open configuration, the first plastic material being capable of expanding at high temperature and/or pressure; placing the mold in a closed configuration wherein a first gap separates the upper ridge of the blade from the lower surface of the movable slide; and applying high temperature and/or high pressure in the mold. The step of applying high temperature and/or high pressure comprises: a first stage corresponding to a first gap between the blade and the movable slide, allowing at least a portion of the first plastic material to expand; then, the sliding part is displaced towards the direction of the ruler strip until a second gap which is smaller than the first gap is formed; then, a second phase, corresponding to said second gap between the blade and the movable slide; said displacement of the slider in the direction of the blade results in a densification of the at least partially expanded first plastic material arranged between said slider and said blade.

the upper ridge of the blade is formed by the intersection of two lateral faces forming an angle different from 0 but less than 20 °, preferably between 6 ° and 10 °;

-the blade is movable relative to the remainder of the first part of the mould;

the movable slide is configured so that its displacement towards the blade densely sets the at least partially expanded first plastic material on both sides of the blade.

Drawings

The invention will be better understood on reading the following non-limiting description, given by way of example only, and with reference to the accompanying drawings, in which:

figures 1 and 2 are sectional views of a sound-absorbing component according to a first embodiment of the invention in a first configuration and a second configuration, respectively;

figures 3 and 4 are cross-sectional views of a sound-absorbing component according to a second embodiment of the invention, in a first configuration and a second configuration, respectively;

figure 5 is a sectional view of a structure for a motor vehicle comprising a sound-absorbing component as shown in figures 1 and 2;

fig. 6 is a schematic cross-sectional view of a manufacturing device of the sound-absorbing component of fig. 1 and 2, during a first step of a manufacturing method according to an embodiment of the invention;

figures 7 and 8 are detailed views of the device of figure 6 according to a second step and a third step of the manufacturing method, respectively.

Detailed Description

Fig. 1 to 2 and 3 to 4 show a first and a second sound-absorbing component 10,110, respectively, according to a first and a second embodiment of the present invention, respectively.

In the following description, the components 10 and 110 are described simultaneously, and similar elements of both components are indicated by the same reference numerals.

The component 10,110 is formed from a first expanded plastics material and includes: a base 14,114 defining at least one internal cavity 16,116,117; at least one lid 18,118,119; and at least one hinge portion 20,120,122.

Preferably, the first expanded plastic material 12 comprises a thermoplastic polymer, more preferably selected from polyethylene, polypropylene and polystyrene.

In each of the first and second embodiments, the base 14,114 includes a lower surface 26 and an upper surface 28, preferably with the lower surface 26 and the upper surface 28 being substantially planar and parallel. In the following description, the orthogonal basis (X, Y, Z) is considered, wherein the lower surface 26 and the upper surface 28 are arranged in a plane (X, Y).

In the first embodiment of fig. 1 and 2, the base 14 includes a floor 30 defining the lower surface 26. The base plate 30 has a substantially rectangular profile, the edges of which extend along the directions X and Y. The base 14 also comprises four substantially planar lateral walls 32,34,36, each of which extends from the edge of the floor along the direction Z. More specifically, the base 14 includes first and second lateral walls 32,34 disposed along planes (X, Y) and third and fourth lateral walls 36 disposed along planes (X, Z).

The upper ends of the lateral walls 32,34,36 are formed by the upper surface 28. The internal cavity 16 defined by the bottom plate 30 and the lateral walls 32,34,36 is generally parallelepiped-shaped.

In the second embodiment of fig. 3 and 4, the base 14 comprises walls 132,134,136 that are substantially planar and parallel to the direction Y, said walls extending obliquely between the upper surface 26 and the lower surface 28 to form a substantially sinusoidal profile. More specifically, the base 114 includes a first series of walls 132,134 and a second series of walls 136. Each series comprises one or more walls, the walls of the same series being parallel to each other. Each wall 132,134,136 has an inclined cross-section in the plane (X, Z), the walls of the first and second series being inclined at an angle a relative to each other. By way of example, in the embodiment of fig. 3 and 4, the angle α is about 60 ° and the base has a cross-section arranged generally forming an equilateral triangle.

The base 114 is formed by the succession of alternating walls of the first series of walls 132,134 and the second series of walls 136, which are fixed to each other at the upper surface 26 and/or the lower surface 28. Preferably, the first wall 132 and the second wall 134 forming the ends of the base 114 along the X belong to a first series and are parallel to each other.

The number of alternating walls 132,134,136 is selected based on, among other things, the desired length along X of base 14.

The base 114 defines a first interior cavity 116 that opens upwardly and a second interior cavity 117 that opens downwardly. Each of the first internal cavity 116 and the second internal cavity 117 is in the shape of one or more prisms arranged along X, each prism extending along Y.

At least one cover 18,118,120 of component 10,110 has a generally planar assembly plane 38 for contacting base 14,114 in the closed configuration of the component 10, 110.

In the first embodiment of fig. 1 and 2, the cover 18 includes a flat top 40 and four lateral panels 42,44,46, the flat top 40 and the four lateral panels 42,44,46 being generally planar and having a generally rectangular profile. In the closed configuration of fig. 2, the edges of the flat top 40 extend along directions X and Y and each of the lateral panels 42,44,46 extends from the edges of the flat top along a square Z. The ends of the lateral panels 42,44,46 opposite the flat top 40 are formed by the assembly surface 38.

In the closed configuration, the first and second lateral panels 42,44 are disposed along planes (Y, Z) from the first and second lateral walls 32,34, respectively, of the base 14; the third and fourth lateral walls 23 of the sub-base 14 of the third and fourth lateral panels 46 are arranged along planes (X, Z).

More precisely, in the first embodiment, the cover 18 of the component 10 has substantially the same shape as the base 14. In the open configuration of fig. 1, the bottom panel 30 and the flat top 40 are placed in the same plane (X, Y) and the base 16 and the lid 18 are generally symmetrical to each other about a plane of symmetry (Y, Z) through the hinge portion 20.

According to a not shown variant of the embodiment of fig. 1 and 2, the cover 18 is in the shape of a substantially planar plate.

In the second embodiment of fig. 3 and 4, the member 110 includes first and second substantially identical covers 118 and 119. Each cap 118,119 is in the shape of a generally planar plate of generally rectangular outline. In the closed configuration of fig. 4, the rim of each cover 118,119 extends along direction X and direction Y.

At least one hinge 20,120,122 of component 10,110 hingedly connects the or each cover 18,118,119, 18,118,119 with base 14, 114. More specifically, in the embodiment shown, each hinge portion 20,120,122 forms a pivotal connection about an axis that is generally parallel to Y. The or each cover 18,118,119, 18,118,119, may thus be reversibly displaceable relative to the base 14,114 between an open configuration and a closed configuration. The form of the hinge 20,120,122 will be described later.

In the first embodiment of fig. 1 and 2, the hinge 20 couples the first lateral wall 32 of the base 14 to the first lateral panel 42 of the lid 18. In the closed configuration of fig. 2, the assembly surface 38 of the cover 18 is in contact with the upper surface 28 of the base 14, thus forming a closed volume 48 that includes the internal cavity 16.

In the second embodiment of fig. 3 and 4, the member 110 includes a first hinge portion 120 and a second hinge portion 122 that hingedly connect the first and second covers 118 and 119 to the first and second walls 132 and 134 of the base 114, respectively. First and second hinge portions 120 and 122 are provided at the upper and lower surfaces 28 and 26, respectively, of the base 114. In the closed configuration of fig. 4, the assembly surface 38 of each of the first and second covers 118,119 is in contact with the upper and lower surfaces 28, 26, respectively. In the closed configuration shown in fig. 4, the first and second covers 118,119 thus define closed cross-sections of the first and second cavities 116,117, respectively.

According to an embodiment, the component 10 further comprises lateral walls (not shown) which, in the closed configuration of fig. 4, enclose the first cavity 116 and the second cavity 117 along Y. These lateral walls may be added or formed by components with the base 114 and/or the first cover 118 and/or the second cover 119.

In the open configuration of fig. 3, the first cover 118 and the second cover 119 are deployed from the base 114 along both sides X. A plurality of parts 110 of identical shape can thus be stacked along Z, with the bases 114 fitting into each other, which allows a space gain for storing and transporting said parts 110.

The hinge portion 20,120,122 of the components 10,110 will now be described in detail below. Hinge 20,120,122 is formed by a flexible strip of first expanded plastic material 12 extending along Y between two lateral edges forming joints with base 14,114 and with respective lid 18,118,119. The hinge portion 20,120,122 is formed in one piece with the base 14,114 and corresponding cover 18,118,119.

As will be described in detail below, the first expanded plastic material 12 of the component 10,110 has a first density d at the base 14,114₁And has a density d at hinge 20,120,122 greater than the first density₁Second density d of₂。

The first expanded plastic material 12 of the component 10,110 has a third density d at the cover 18,118,119 corresponding to the hinge 20,120,122₃. According to an embodiment, the third density d of the cover₃Substantially equal to the first density d of the base 14,114₁. According to another embodiment, the third density d of the cover₃Greater than the first density d of the base 14,114₁And preferably between said first density d₁And a second density d of the hinge 20,120,122₂In the meantime.

Preferably, the thickness of hinge portion 20,120,122 is substantially less than the average thickness of base portions 14, 114. The thickness of the base portion 14,114 imparts rigidity thereto as compared to the flexibility of the hinge portion 20,120,122.

By way of example, in the first embodiment of fig. 1 and 2, the hinge portion 20 has an average thickness of 0.5mm and the base portion 14 has an average thickness of 15 mm.

Fig. 5 shows a structure 200 for a motor vehicle, for example a floor panel of a vehicle, similar to the floor panel described in document FR 3026080. The structure 200 includes a body 202 formed of a second plastic material 204 that defines at least one sound absorbing chamber 206. The sound absorbing chamber 206 encloses the sound absorbing member 10 in a closed configuration as shown in fig. 2.

In the embodiment shown, the structure 200 comprises a plurality of sound-absorbing chambers 206, each of which encloses the same component 10.

Preferably, the second plastic material is expanded. Preferably, the second plastic material comprises polyurethane.

A method of manufacturing the component 10 of fig. 1 and 2 will now be described with the aid of fig. 6 to 8.

Fig. 6 shows a schematic cross-sectional view of a manufacturing apparatus 300 for the component 10. The manufacturing apparatus 300 comprises a mold 302 comprising a first element 304 and a second element 306, which are displaceable relative to each other.

The first element 304, or female element, of the mold 302 includes a stamp corresponding to the outer surface of the part 10 in the closed configuration of fig. 2. The second element 306 or male element of the mold 302 includes a impression corresponding to the walls of the interior volume 48 of the component 10 in the closed configuration of fig. 2.

Consider the normalized orthogonal basis (X ', Y ', Z ') associated with the female element 304 of the mold 302. In the following description, it is considered that the male element 306 is movable in translation vertically, i.e. in the direction Z', with respect to the female element 304.

The stamp of each of the female element 304 and the male element 306 comprises two substantially identical portions, which correspond to the base 14 and the cover 18, respectively, described above. The cross-sectional planes of fig. 6 to 8 are planes (X ', Y ') considering that the two substantially identical portions of each stamp are aligned along direction X '.

More specifically, the stamp of the female element 304 comprises two substantially identical planar portions 308, which correspond to the surfaces of the aforementioned bottom plate 30 and flat top 40, respectively. The stamp of the male element 306 comprises two similar flat portions 310.

The female element 304 includes a blade 312 that extends in a generally straight manner along Y'. More particularly, as can be seen in fig. 7 and 8, the blade 312 includes two generally planar lateral faces 314 that are joined at an upper edge 316. The lateral face 314 corresponds to the respective impressions of the aforementioned first lateral wall 32 and first lateral panel 42.

Preferably, the blade 312 is substantially triangular in cross-section, each lateral face 314 forming an angle β other than 0 with the vertical direction Z'. The angle β is less than 10 ° and preferably between 3 ° and 5 °.

Similarly, the aforementioned planar portions 308,310 of the impression of the mold 302 are inclined at an angle β relative to horizontal.

The blade 316 corresponds to the impression of the hinge 20. The blade 316 has a small width 318, e.g., about 2 to 4mm, along X'. Preferably, the blade 312 is movable relative to the planar portion 308 of the female element 304 of the die to enable replacement in the event of wear or failure.

The impression of the male element 306 comprises two facets 320 substantially facing each other, which correspond respectively to the aforementioned first lateral wall 32 and first lateral panel 42. Each facet is inclined at an angle beta with respect to the vertical. Each land 320 extends upwardly through a generally vertical planar guide 322.

The male member 306 also includes a slide 324 extending generally straight along Y'. The slider 324 is capable of sliding vertically between the two rails 322.

The slider 324 includes a lower surface 326 with a central portion 327 corresponding to the impression of the hinge 20. Preferably, the lateral portions of said lower surface 326 correspond to the ends of the aforesaid first lateral wall 32 and first lateral panel 42.

The manufacturing apparatus 300 further includes an injection device (not shown) injecting water vapor into the inside of the mold 302, and a heating and pressurizing device (not shown) heating and heating the inside of the mold.

In a first step of the manufacturing method of manufacturing the component 10, the mold 302 is in an open configuration such as shown in fig. 6, wherein the male element 306 is spaced apart from the female element 304.

The first step of the method comprises depositing particles 330 comprising the first plastic material 12 in the impression of the female element 304. Preferably, the particles 330 also include at least one foaming agent that allows the first plastic material 12 to expand at high temperatures and/or pressures.

The particles 330 are for example similar to those described in document EP 1693255.

In a second step of the method, the male element 306 is brought close to the female element 304 along Z' in order to place the mould 302 in the initial closed configuration, as shown in fig. 7. In the initial closed configuration, a first gap 332 measured along Z' separates the upper ridge 316 of the blade 312 from the lower surface of the slider 324.

In a third step of the method, high temperature and high pressure are applied in the mould 302 to allow the first plastic material of the particles 330 to expand. Preferably, the third step comprises first injecting water vapour into the interior of the mould 302 between the female element 304 and the male element 306.

The third step includes a first stage during which a gap 332 is maintained between the blade 312 and the slide 324. This first stage allows at least a portion of the first plastic material 12 of the particles 330 to expand and allow a foam 334 to form between the ridge 316 of the blade 312 and the lower surface 326 of the slider 324.

The third step then includes displacing the slide 32 along Z' in the direction of the blade 312 until a second gap 336 that is less than the first gap 332. This displacement of the slider 32 compresses the foam 334 formed between the blade 312 and the slider 324, thereby effecting a densified region 338 of the first expanded plastic material 12.

The third step then includes a second phase of applying high temperature and pressure during which a second gap 336 is maintained between the blade 312 and the slide 324. This second stage allows the expansion of the first plastic material 12 to be completed.

By way of example, the first gap 332 is about 15mm and the second gap is about 0.5 mm.

The mold is then brought to room temperature and pressure, which allows the first plastic material 12 to cure.

The aforementioned part 10 is thus obtained in the open configuration. The hinge 20 is formed by a portion of the densified region 338 between the ridge 316 of the blade 312 and the central portion 327 of the lower surface 326 of the slider 324.

At a distance from the fold 20, the base 14 of the obtained component 10 has a first density d of the first plastic material 12₁(ii) a The hinge portion 20 has a second density d₂。

Generally, the densified region 338 corresponds to at least the hinge portion 20 of the component 10. Preferably, as in the first embodiment shown, the densified region 338 also extends over the ends of the aforementioned first lateral wall 32 and first lateral panel 42, which strengthens the mechanical connection of the flap 20 to the base 14 and lid 18.

According to an embodiment not shown, the manufacturing method also allows compacting the foam 334 at the cover of the component to make it more resistant to mechanical stresses. The compression is performed by means of a movable slide similar to slide 334. According to another embodiment, not shown, the cover is reinforced by forming slots in the mould, rather than by compacting the foam.

The manufacturing method as described previously allows to obtain a hollow part 10,110 which is more lightweight while maintaining good mechanical and acoustic properties. The presence of one or more hinges 20,120,122 allows the component 10,110 to be formed in an integral manner rather than from multiple elements, which simplifies the manufacturing process. Furthermore, the second embodiment of fig. 3 and 4 allows to obtain space gain in case of an open configuration upon storage/transport.

A method of manufacturing the structure 200 of fig. 5 will now be described. The component 10 obtained by the method described above is placed in the closed configuration of fig. 2 by folding the flap 20 to bring the lid 18 into contact with the base 14. Optionally, the internal cavity 16 is pre-filled with an acoustic insulation material, such as recycled felt, acoustic fibers, or an acoustic nonwoven. As a variant, the closed volume 48 is evacuated.

A similar plurality of parts 10 in a closed configuration are placed in a mold and then a second plastic material 204 (e.g., polyurethane) is overmolded onto the parts 10 to form the aforementioned body 202.

Claims

1. A sound-absorbing component for a motor vehicle, formed from a first expanded plastic material, the component comprising a base defining an internal cavity, the base comprising at least one first wall and at least one second wall facing each other,

the method is characterized in that:

-the component further comprises a lid and a hinge hinging the lid to the first wall of the base; said cover being able to be assembled with said second wall in the closed configuration of said part;

-the base, the lid and the hinge are formed in one piece, the hinge being formed by a flexible strip of the first expanded plastic material; and

-the first expanded plastic material has a first density at the base portion and a second density at the hinge portion greater than the first density.

2. A component according to claim 1, characterised in that the first expanded plastic material comprises a thermoplastic polymer.

3. A component according to claim 2, characterized in that the thermoplastic polymer is selected from polyethylene, polypropylene and polystyrene.

4. A component according to claim 1 or 2, configured such that in the closed configuration the internal cavity forms a volume closed by the cover.

5. A component according to claim 1 or 2, configured such that the base defines two internal cavities, the component further comprising two covers, each of the covers being hinged to the base by a different hinge.

6. A structure for a motor vehicle, characterized by comprising: at least one sound absorbing component according to any one of the preceding claims in a closed configuration; and a second plastic material overmolded on the at least one component.

7. The structure of claim 6, wherein the second plastic material comprises polyurethane.