Filtering front structure of motor vehicle

Abstract

Front structure of a motor vehicle, comprising a cradle (12) adapted to extend transversely under an engine of a motor vehicle, said front structure comprising two extensions (16, 18) extending longitudinally towards the front of said vehicle, each of said extensions (16, 18) having a rear portion (36) connected to the cradle (12) characterized in that it comprises a cross member (24) having two opposite ends (38, 40), said two opposite ends (38, 40) of said cross member (24) being connected respectively to said rear portions (36) of said extensions (16, 18) by means of an elastic joint (42, 44) to absorb the vibrations produced by said engine. Figure to be published with the abbreviation: Figure 2

Description

Title of the invention: Filtering front structure for motor vehicles

[0001] The invention relates to a front structure of a motor vehicle comprising a cradle adapted to extend in a transverse direction under an engine group in order to be able to support it at least in part.

[0002] Known motor vehicles usually include a passenger compartment and an engine compartment located at the front of the vehicle and delimited from the passenger compartment by a bulkhead.

[0003] They also include two substantially parallel longitudinal members which extend in a longitudinal direction at a distance from each other through the bulkhead and into the engine compartment.

[0004] Approximately directly above the firewall, and partially beneath the engine compartment, the vehicle comprises a subframe extending transversely from which two extensions extend longitudinally forward beneath the rest of the engine compartment. These two extensions themselves extend approximately directly above the two longitudinal members and are generally suspended from them by means of a suspension component.

[0005] Also, the motor vehicle includes a technical front end which notably includes the vehicle's radiator.

[0006] The cradle is adapted to provide several main interface functions and in particular to accommodate the engine group and optionally to accommodate a cooling or air conditioning system.

[0007] For the same type of vehicle manufactured over the years, engine assemblies may evolve according to, for example, technological developments and regulatory changes. These modifications may lead to a change in the engine assembly's structure. Modifying the engine assembly's structure may require creating new connection points between the subframe and the engine assembly. These new support and connection points allow the engine to be supported. They must, however, be able to filter the vibrations it produces.

[0008] It is therefore necessary to modify the cradle, which may generate relatively high new investments.

[0009] A problem which then arises and which the present invention aims to solve is to provide a front structure for a motor vehicle which can not only accommodate a wide variety of powertrains while filtering the vibrations they produce, but which can also be made at an advantageous cost.

[0010] To this end, a front structure for a motor vehicle is proposed, comprising a cradle adapted to extend transversely under the engine of a motor vehicle. This front structure comprises two extensions extending longitudinally towards the front of the vehicle, each extension having a rear portion connected to the cradle. The front structure includes a crossmember having two opposite ends, these two opposite ends of the crossmember being connected to the rear portions of the extensions by means of an elastic joint to absorb the vibrations produced by the engine.

[0011] Thus, one of the features of the invention lies in the implementation of a cross member connected to the cradle by elastic joints. The cross member allows the engine assembly to be held, at least partially. In addition, it allows for the addition of connection points between the cradle and the engine assembly.

[0012] Since the cross member is connected to the extensions of the cradle by elastic joints, the vibrations produced by the motor unit, and transmitted to the cross member via the added connection points, are then filtered and absorbed at the level of the elastic joints.

[0013] Preferably, the elastic joint comprises two coaxial rings separated by a sleeve made of elastically deformable polymer material. In other words, the two rings have different diameters to define an annular space between them in which the elastic sleeve is engaged. For example, the diameter of the larger ring is more than twice the diameter of the smaller one. Furthermore, the polymer material used can be polyurethane or natural rubber. Any other elastically deformable material can be used, for example, silicone. Also, according to an alternative embodiment, a fluid material encapsulated in a reservoir formed within the elastomer body is used.

[0014] The sleeves will thus absorb the vibrations of the engine assembly to prevent them from propagating into the subframe and then through the vehicle. Furthermore, they reduce noise. In addition, vibration absorption helps to preserve the structure and therefore increases its lifespan.

[0015] Advantageously, according to the invention, the elastic joint comprises an inner metal ring located inside the sleeve and an outer metal ring surrounding the sleeve. The outer diameter of the inner metal ring is equal to the inner diameter of the sleeve, while the inner diameter of the outer ring is equal to the outer diameter of the sleeve. Thus, the inner ring is engaged inside the sleeve, while the sleeve itself is engaged in the outer ring, with no play between the three elements.

[0016] Preferably, each of the rear parts of said extensions comprises an anchoring member, said anchoring members being oriented towards each other.

[0017] Advantageously, the anchoring member has a notch receiving the outer ring of the elastic joint. According to the invention, the outer ring is welded to the anchoring member in the notch.

[0018] According to one embodiment of the invention, the elastic joint has an axis oriented along a component perpendicular to a transverse direction and a longitudinal direction.

[0019] According to another embodiment of the invention, the elastic joint has an axis oriented along a component perpendicular to a transverse direction and a vertical direction.

[0020] Furthermore, according to a particularly advantageous embodiment of the invention, the cross member is U-shaped. In this way, the anchoring elements and elastic joints extend respectively inside the two ends of the cross member, and a screw is then engaged through the two opposite flanges of the cross member and through the inner ring. Thus, the two ends of the cross member are perfectly secured to the side members.

[0021] The invention also relates to a motor vehicle comprising a front structure as described above.

[0022] Other features and advantages of the invention will become apparent from the following description of several particular embodiments of the invention, given by way of example but not limitation, with reference to the accompanying drawings in which:

[0023] - [Fig. 1] is a schematic right-front perspective view of a front structure of motor vehicle conforming to the invention;

[0024] - [Fig.2] is a schematic front view of a vehicle front structure automobile according to the invention;

[0025] - [Fig.3] is a schematic front view of a vehicle front structure automobile according to another method of implementation; and,

[0026] - [Fig.4] is a schematic front view of a vehicle front structure automobile according to another method of implementation;

[0027] - [Fig.5] is a schematic axial cross-sectional view of an element of the invention illustrated in [Fig. 1]; and,

[0028] - [Fig.6] is a schematic side view of the object in [Fig.5].

[0029] Fig. 1 illustrates a front structure 10 of a motor vehicle inscribed in a frame (XY, Z), and extending longitudinally from front to rear along the X axis, transversely from left to right in driving situation, along the Y axis and vertically opposite the support surface along the Z axis.

[0030] In [Fig.1], the front structure 10 includes a cradle 12 which extends in the transverse direction Y and in the longitudinal direction X at least partially under the engine compartment, not shown here.

[0031] The front structure also includes two extensions, a right extension 16 and a left extension 18. The extensions 16, 18 are connected to the cradle 12 and extend substantially along the longitudinal direction X.

[0032] The extensions 16, 18 have a front part 34 and a rear part 36 opposite the front part 34. The rear part 36 is connected to the cradle 12.

[0033] Also, in the extension of the extensions 16, 18, at the level of their front part 34, the front structure 10 includes shock absorbers, or "crash-box", right 22 and left 20. And the two shock absorbers 20, 22 are connected together by a front cross member 23.

[0034] The front structure includes a rear cross member 24, referred to as the cross member in the following description, to which the powertrain, not shown here, is adapted to be connected.

[0035] The cross member 24 is preferably made of a metallic material such as steel or an aluminum alloy. It can also be made of a composite material comprising, for example, resin and fiberglass or carbon fiber.

[0036] In addition, the cross member 24 shown in [Fig.1] to [Fig.4] is U-shaped. In other words, it has a bottom and two free wings opposite each other.

[0037] The cross member 24 has two ends opposite each other: a left end 40 and a right end 38, which ends are respectively connected to the rear parts 36 of the extensions 16, 18.

[0038] As illustrated in more detail in [Fig.2], the left end 40 of the cross member 24 is connected to the rear part 36 of the left extension 18 by means of a left elastic joint 44, while the right end 38 is connected to the rear part 36 of the right extension 16 by means of a right elastic joint 42.

[0039] The elastic joints 42, 44 are intended to absorb the vibrations produced by the powertrain and transmitted to the cross member 24.

[0040] The invention is not limited to a single elastic joint for each end. The number of elastic joints for each end can be greater than one and can be chosen according to the desired vibration absorption.

[0041] The elastic joints 42, 44, are identical. An elastic joint according to the invention cooperating with the cross member 24 will be described in detail opposite [Fig. 5] and [Fig. 6]. The cross member 24 thus has a U-shaped cross-section. It comprises a base 43 and two opposing flanges 45, 47.

[0042] Thus, as illustrated in [Fig.5] and [Fig.6], each elastic joint 42, 44 comprises two coaxial rings 46, 48 separated by an elastically deformable sleeve 50: an inner ring 46 located inside the sleeve 50 and an outer ring 48 surrounding the sleeve 50.

[0043] The elastic joints 42, 44 each have a joint axis A.

[0044] The coaxial rings 46, 48 are made of a metallic material such as aluminum or steel, for example. The sleeve 50 is made of an elastically deformable polymer material. For example, it is made of a synthetic elastomer such as polyurethane or silicone. According to another embodiment, a fluid material is encapsulated in a reservoir formed within the mass of an elastomer. Natural rubber can also be used.

[0045] The elastic joints 42, 44 are connected to the rear portions 36 of the extensions by means of an anchoring member 56, partially shown here. The anchoring members 56, respectively fixed to the rear portions 36 of the extensions 16, 18, have a "wolf's mouth" notch 58 within which the outer rings 48 of the joints 42, 44 are supported.

[0046] The outer rings 48 are then welded in their contact area with the anchoring member 56.

[0047] Also, the elastic joints 42, 44 are connected to the cross member 24 by a screwable fixing means comprising a screw 52 and a nut 54.

[0048] Indeed, each of the rear portions 34 of the extensions 16, 18 includes an anchoring member 56. The anchoring members 56 are oriented towards each other so as to face each other. Thus, two opposite ends 38, 40 of the cross member 24 respectively engage with the anchoring members 56 via the elastic joints 42, 44.

[0049] The front structure 10 is partially shown in exploded perspective in [Fig. 4]. The cross member 24 is shown with elastic joints 42, 44 adapted to connect its two opposite ends 38, 40 to the two anchoring members 56. Thus, the cross member 24 is oriented along its axis so that the axis A of the elastic joints 42, 44 is oriented along a component perpendicular to the transverse direction Y and the longitudinal direction X, and in other words, along a component parallel to the vertical direction Z.

[0050] The cross member 24 can be oriented so that the axis A of the joints 42, 44 is inclined with respect to the vertical direction Z at an angle of 25 degrees.

[0051] As represented on [Fig.3], the cross member 24 is oriented so that the axis A of the elastic joints 42, 44 is oriented along a component perpendicular to the transverse direction Y and to the vertical direction Z and in other words along a component parallel to the longitudinal direction X.

[0052] The cross member 24 can be oriented so that the axis A is inclined with respect to the longitudinal direction X at an angle of 25 degrees.

Claims

Demands

1. Front structure of a motor vehicle, comprising a cradle (12) adapted to extend in a transverse direction under an engine group of a motor vehicle, said front structure comprising two extensions (16, 18) extending in a longitudinal direction towards the front of said vehicle, each of said extensions (16, 18) having a rear portion (36) connected to the cradle (12); characterized in that it comprises a cross member (24) having two opposite ends (38, 40), said two opposite ends (38, 40) of said cross member (24) being connected respectively to said rear portions (36) of said extensions (16, 18) by means of an elastic joint (42, 44) to absorb the vibrations produced by said engine group.

2. Front structure according to claim 1, characterized in that the elastic joint (42, 44) comprises two coaxial rings (46, 48) separated by a sleeve (50) made of elastically deformable polymer material.

3. Front structure according to claim 2, characterized in that the elastic joint (42, 44) comprises an inner metal ring (46) located inside the sleeve (50) and an outer metal ring (48) surrounding the sleeve (50).

4. Front structure according to claim 2 or 3 characterized in that each of the rear parts (36) of said extensions (16, 18) comprises an anchoring member (56), the anchoring members (56) being oriented towards each other.

5. Front structure according to claim 3 and 4 characterized in that the anchoring member (56) has a notch (58) receiving the outer ring (48) of the elastic joint (42, 44).

6. Front structure according to any one of claims 2 to 5, characterized in that the elastic joint (42, 44) has an axis (A) oriented along a component perpendicular to a transverse direction and a longitudinal direction.

7. Front structure according to any one of claims 2 to 5, characterized in that the elastic joint (42, 44) has an axis (A) oriented along a component perpendicular to a transverse direction and a vertical direction.

8. Front structure according to any one of claims 1 to 7, characterized in that said cross member (24) is U-shaped.

9. Motor vehicle comprising a front structure according to any one of claims 1 to 8.

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