Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R19/00—Wheel guards; Radiator guards, e.g. grilles; Obstruction removers; Fittings damping bouncing force in collisions
  • B60R19/02—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects
  • B60R19/24—Arrangements for mounting bumpers on vehicles
  • B60R19/26—Arrangements for mounting bumpers on vehicles comprising yieldable mounting means
  • B60R19/34—Arrangements for mounting bumpers on vehicles comprising yieldable mounting means destroyed upon impact, e.g. one-shot type
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R19/00—Wheel guards; Radiator guards, e.g. grilles; Obstruction removers; Fittings damping bouncing force in collisions
  • B60R19/02—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects
  • B60R19/18—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects characterised by the cross-section; Means within the bumper to absorb impact
  • B60R19/22—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects characterised by the cross-section; Means within the bumper to absorb impact containing mainly cellular material, e.g. solid foam

Definitions

• the invention relates to an energy absorbing housing intended to be placed between the end of a longitudinal member of a motor vehicle and a bumper beam.
• an energy absorbing housing for a bumper beam of a motor vehicle comprising a casing constituted by a hollow profile which has a first end suitable for being attached to the bumper beam and a second end suitable for being fixed at the end of a longitudinal member of a motor vehicle.
• the front panel capable of integrating various vehicle equipment such as headlights, turn signals, horn, etc.
• the front panel constitutes a modular element ready to be mounted on the vehicle. Its mounting is done by connection to lateral structural elements of the vehicle, such as the side members, then by the installation of a bumper attached to the module.
• Energy absorbing boxes are arranged between each of the side members and the bumper beam. These absorber boxes must meet strict standards in order to be able to absorb the energy of a standardized shock known as Danner shock corresponding to the impact of the vehicle against a fixed obstacle at a speed of 16 km / h. Energy absorption must be obtained without the peak force recorded in the housing exceeding a maximum limit, for example 120kN.
• the cost of car insurance is calculated based on the cost of repairs to vehicles after a frontal impact at 16 km / hour.
• the object of the present invention is precisely to respond to these various difficulties. Its purpose is to maximize the ratios of absorbed energy compared to the mass of the energy absorber (ratio of energy by mass) and the absorbed energy compared to the intrusion of the object which strikes the vehicle or against which the vehicle collides with (ratio of energy by intrusion). Maximizing these ratios makes it possible to reduce the damage caused to a front panel of a vehicle during a frontal impact and consequently the cost of repairs and the insurance premium.
• the envelope is lined with a metallic foam having energy absorption properties whose density is between 0.1 g / cm 3 and 0, 4 g / cm 3 .
• the foam makes it possible to reduce the thickness of the envelope and consequently the mass of the absorber box, as well as the overhang of the vehicle.
• the section of the envelope is rectangular, in particular square. In another embodiment, the cross section of the envelope is circular.
• the housing can be made of aluminum or steel.
• the side of this square is advantageously between 50 and 80 mm, which corresponds to a cross-sectional area between 2500 mm 2 and 6400 mm 2 .
• the length of the housing is advantageously between 80 mm and 200 mm and its thickness between 1.5 mm and 3 mm.
• Figure 1 is an overall view of a bumper beam and an energy absorbing housing mounted on a front face of a motor vehicle;
• Figure 2 is a perspective view of an energy absorbing housing according to the present invention.
• FIGS. 3 to 8 are curves which represent the variations of the energy by mass and of the energy by intrusion as a function of the density of the foam for different values of parameters of the housing.
• FIG. 1 There is shown schematically in FIG. 1 a bumper beam 2 constituted by a hollow profile, for example of open section (C or U) or else of closed section, in which is housed at least partially a shock absorber housing. energy 4.
• This box 4 is fixed to the structure of a motor vehicle, here at the end of a lower spar 6 on which is also fixed a front face module 8.
• the bumper beam is intended to receive a bumper 10, also called front shield.
• FIG 2 a schematic perspective view of the energy absorbing housing 4 of Figure 1.
• the housing 4 has a square section, but this section could also be rectangular or circular.
• the housing 4 has a length L and the side of its cross section has been designated by the letter a.
• the casing envelope for example made of aluminum, has a thickness e.
• the interior of the housing is lined with foam 12 having energy absorbing properties.
• the alloy used to make the housing 4 is preferably an aluminum from the 6000 series (6060, 6106 and 6082). Different heat treatments are possible, in particular those known under the names T4, T5, T51 or T6 according to the standards in force.
• the housing can also be made of steel.
• An aluminum energy-absorbing housing was produced having a thickness of 2.9 mm and a length L of 130 mm. The weight of this case is 460 grams.
• the housing incorporating the towing eye has a mass of 540 grams.
• a shock absorbing steel housing with a thickness of 1.8 mm and a length L of between 100 and 120 mm was also produced.
• the weight of this box is 0.8 kg and 1.12 kg for the box incorporating the towing eye.
• An energy absorbing housing was produced having a square cross section of 2500 mm 2 (side of 50 mm).
• the density of the foam is between 0.2 and 0.4 g / cm 3 .
• the energy ratio by mass is less than or equal to 40 and the energy ratio by intrusion is less than or equal to 120.
• FIG. 3 shows the variations in the energy by mass (SEA) and energy by intrusion (SEI) ratios for two given aluminum alloys from the 6000 series, namely respectively the 6060 alloy, corresponding to the curves SEA 57 and SEI 57 and the alloy 6082 corresponding to the curves SEA 300 and SEI 300.
• the variations are expressed as a function of the density D in g / cm 3 of the metal foam.
• the energy ratio by mass is between approximately 10.71 and 27.49 and the energy ratio by intrusion is included substantially between 22.48 and 65.64.
• the energy ratio by mass is between substantially 34.5 and 36.7, while the energy ratio by intrusion is between substantially 77 and 89.
• the energy ratio by mass is between 20 and 40 and / or the energy ratio by intrusion is between 75 and 120.
• Optimized performance is obtained for a density D of between 0.2 and 0.4 g / cm 3 .
• FIG. 4 shows the variations of these two ratios for a foam density of between 0.1 and 0.5 g / cm 3 , for a square absorber with a side of 50 mm and a length of 140 mm.
• the energy ratio by mass is approximately between 24.13 and 24.56, while the energy ratio by intrusion is approximately between 61.79 and 79.
• the energy absorption ratio by mass is included between 10 and 20 and / or the energy ratio by intrusion is between 45 and 75.
• FIG. 5 shows the variations of these two ratios for a box with a square section of 50 mm on a side and of length L equal to 200 mm for a foam density of between 0.1 and 0.4 g / cm 3 .
• the energy ratio by mass is between 20.38 and 19.62, while the energy ratio by intrusion is between 57.27 and 69.73.
• the absorption ratio by mass is less than or equal to 25 and / or the energy ratio by intrusion is less than or equal to 105.
• FIG. 6 shows the variations of these two ratios for two aluminum alloys, namely the alloy
• 6082 corresponding to the SEA 300 and SEI 300 curves for foam densities between 0.15 and 0.3 grams per cm 3 .
• the energy ratio by absorption is between 18.8 and 18.42, while the energy ratio by intrusion is between 52.38 and
• the energy ratio by absorption SEA 300 is between 25.89 and 18.62, while the energy ratio by intrusion SEI 300 is between 83.72 and 113.55 .
• the energy absorption ratio is between 12 and 25 and / or the energy ratio by intrusion is between 65 and 105.
• FIG. 7 shows the variations of these two ratios for two aluminum alloys, namely the alloy 6060 corresponding to the curves SEA 57 AND SEI 57 and the alloy 6082 corresponding to the curves SEA 300 and SEI 300
• the energy ratio by absorption is between 13.36 and 12.48, while the energy ratio by intrusion is between 58.35 and 99.66.
• the energy ratio by mass is between 15.7 and 14.38, while the energy ratio by intrusion is between 84.17 and 121.14, for densities between 0.2 g / cm 3 and 0.4 g / cm 3 .
• the energy ratio by mass is between 10 and 15 and / or the energy ratio by intrusion is between 55 and 85 for a density of absorbent metallic foam between 0.15 g / cm 3 and 0.35 g / cm 3 .
• the density of the metallic foam is substantially equal to 0.25 g / cm 3 .

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Vibration Dampers (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=32480285

Family Applications (1)

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• 2002
  • 2002-12-30 FR FR0216855A patent/FR2849416B1/fr not_active Expired - Fee Related
• 2003
  • 2003-12-23 WO PCT/FR2003/003882 patent/WO2004060724A1/fr active Application Filing
  • 2003-12-23 EP EP03799699A patent/EP1578646A1/de not_active Ceased
  • 2003-12-23 US US10/540,796 patent/US7240932B2/en not_active Expired - Lifetime
  • 2003-12-23 JP JP2004564301A patent/JP2006512249A/ja active Pending
  • 2003-12-23 AU AU2003299405A patent/AU2003299405A1/en not_active Abandoned

Non-Patent Citations (1)

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