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EP-4735774-A1 - SHOCK ABSORBER WITH TWO COMPOSITE INSERTS

EP4735774A1EP 4735774 A1EP4735774 A1EP 4735774A1EP-4735774-A1

Abstract

The invention relates to a shock absorber (2) for a motor vehicle, the shock absorber comprising at least one plastic casing (14) and a first composite insert (18), characterised in that the shock absorber (2) comprises at least one additional composite insert (20) that is arranged against the first composite insert (18) with at least one connecting region (52) between the first composite insert (18) and the additional composite insert (20) so as to form a reinforcing assembly (16), the first composite insert (18) and the additional composite insert (20) being arranged on either side of a connecting plane (P) in which the at least one connecting region (52) extends, the plastic casing (14) surrounding the reinforcing assembly (16).

Inventors

  • DA-COSTA-PITO, Sergio
  • MITIDIERI, Enzo
  • LEVASSEUR, NICOLAS
  • KEZMANE, Ali
  • GARDERE, Guillaume
  • BESNARD, Jean-Yves

Assignees

  • Valeo Electrification

Dates

Publication Date
20260506
Application Date
20240626

Claims (10)

  1. 1. Shock absorber (2) for a motor vehicle, comprising at least one plastic casing (14) and a first composite insert (18), characterized in that the shock absorber (2) comprises at least one additional composite insert (20) which is arranged against the first composite insert (18) with at least one junction zone (52) between the first composite insert (18) and the additional composite insert (20) so as to form a reinforcement assembly (16), the first composite insert (18) and the additional composite insert (20) being arranged on either side of a junction plane (P) in which the at least one junction zone (52) extends, the plastic casing (14) surrounding said reinforcement assembly (16).
  2. 2. Shock absorber (2) according to claim 1, in which the first composite insert (18) and the additional composite insert (20) each comprise at least one curved portion (53).
  3. 3. Shock absorber (2) according to claim 2, in which different discontinuous junction zones (52) are formed in the junction plane (P) between the first composite insert (18) and the additional composite insert (20), the curved portions (53) participating in forming at least one hollow body (54) arranged between the composite insert (18) and the additional composite insert (20), the junction plane (P) passing through each hollow body (54).
  4. 4. Shock absorber (2) according to one of the preceding claims, in which the first composite insert (18) and the additional composite insert (20) are symmetrical to each other with respect to the junction plane (P).
  5. 5. Shock absorber (2) according to any one of the preceding claims, in which the plastic casing (14) has two longitudinal end faces (34, 36) and side faces (20, 22, 24, 26), the longitudinal end faces and the side faces being composed of plastic material.
  6. 6. Shock absorber (2) according to claim 5, in combination with claim 3, in which the two longitudinal end faces (34, 36) comprise at least one opening (37) arranged opposite a hollow body (54) formed by the junction of the first composite insert (18) and the additional composite insert (20).
  7. 7. Shock absorber (2) according to any one of claims 1 to 6, in which the first composite insert (18) and the additional composite insert (20) each have a profile formed of curved portions and flat portions forming the functional zones, said profile extending between a first free end (50a) and a second free end (50b), the free ends (50a, 50b) being perpendicular to the junction plane (P).
  8. 8. Shock absorber (2) according to claim 7 in combination with claim 3, in which the first composite insert (18) and the additional composite insert (20) are arranged against each other forming two junction zones between the first composite insert and the additional composite insert which are discontinuous and separated by a single hollow body (54), each of the junction zones extending in the vicinity of one of the free ends (50a, 50b).
  9. 9. Shock absorber (2) according to any one of claims 1 to 6, in combination with claim 3, in which the first composite insert (18) and the additional composite insert (20) comprise free ends (50a, 50b) which extend substantially parallel to the junction plane (P) and which form one of the junction zones (52), the reinforcement assembly comprising at least one hollow body (54) generating a discontinuity between two junction zones (52).
  10. 10. A method of manufacturing a shock absorber (1) according to any one of claims 1 to 9, in combination with claim 2, during which: - The first composite insert (18) and the additional composite insert (20) initially presented in flat form are preheated before placing them in an injection tool (56); - The first composite insert (18) and the additional composite insert (20) are preformed in the injection tool (56) by creating curved portions (53), while maintaining flat contact walls. intended to be pressed against each other to form the junction zones (52); - The first composite insert (18) and the additional composite insert (20) are assembled by pressing their flat contact walls forming at least one flat junction zone (52) against each other when closing the injection tool (56); - Plastic material is injected around the reinforcement assembly formed by the junction of the first composite insert (18) and the additional composite insert (20) once the injection tool (56) is closed.

Description

DESCRIPTION TITLE: SHOCK ABSORBER WITH TWO COMPOSITE INSERTS The present invention relates to the fields of mechanics and passive safety of motor vehicles and more particularly concerns shock absorbers used to absorb the forces undergone, in particular axial forces, by a motor vehicle during a high-speed impact. In order to limit the damage that a motor vehicle and its occupants may suffer in the event of a collision, it is known to equip these vehicles with both active safety devices, which aim in particular to avoid collisions, and passive safety devices, which aim to reduce the intensity of the impact suffered. Thus, motor vehicles are conventionally equipped with shock absorbers, in particular on the front or rear of the vehicle, which are configured to absorb the kinetic energy released during frontal collisions and which thus make it possible to limit the damage that these collisions can cause for users and for the structure of the vehicle itself. Nowadays, it is known to produce these shock absorbers in bi-material, and no longer only in aluminum or steel. These shock absorbers in bi-material can in particular have a plastic casing housing an insert made of composite material. More particularly, the insert has a profile as adapted as possible to the absorption of axial forces and the plastic material is injected around this composite profile to ensure the resistance of the absorber during small impacts. Bi-material shock absorbers known from the state of the art may require a significant portion of plastic material, in particular due to an open profile of the composite insert, for example S-shaped, which requires filling the openings induced by this type of profile with plastic material in order to stabilize the insert within the plastic casing partly constituting the shock absorber. In addition to the cost price of the shock absorber which can be impacted by the massive injection of plastic material, the plastic material of the envelope has the disadvantage of being fragile at low temperatures, which implies a loss of stability of the shock absorber in these extreme conditions so that the quantity of composite material must be controlled it is then interesting to reduce its quantity and to balance this reduction by an addition of composite material. The present invention falls within this context and proposes a shock absorber for a motor vehicle, comprising at least one plastic casing and a first composite insert, characterized in that the shock absorber comprises at least one additional composite insert which is arranged against the first composite insert with at least one junction zone between the first composite insert and the additional composite insert so as to form a reinforcement assembly, the first composite insert and the additional composite insert being arranged on either side of a junction plane in which the at least one junction zone extends, the plastic casing surrounding the reinforcement assembly. The addition of an additional composite insert increases the portion of composite material in the general configuration of the shock absorber and makes it possible to simply generate a composite insert profile, i.e. here a profile of the reinforcement assembly, which may have closed areas not to be filled with the plastic material when injecting the latter. More particularly, bringing the first composite insert and the additional composite insert into contact via one or more junction areas can make it possible to create areas, within the reinforcement assembly formed by these two inserts, which are closed in a given section plane, and this generates fewer areas to be filled with plastic material than when a single composite insert is used. This makes it possible to both reduce the quantity of plastic material required to cover the inserts and to limit the fragility of the assembly in the event of low temperatures and this can allow the creation of hollow zones within the shock absorber, between the two inserts forming the assembly. reinforcement, which generates a shock absorber that is lighter and less expensive but just as effective since the quantity of composite material is significant. According to an optional feature of the invention, the first composite insert and the additional composite insert each comprise at least one curved portion. The curved portions help to stabilize the insert during its deformation. Each curved portion is considered here in a plane perpendicular to the axial direction of the force that the shock absorber must absorb in the event of a frontal collision. In other words, for a shock absorber arranged on the front or rear of the vehicle and which must absorb a longitudinal axial force, each curved portion is considered in a vertical and transverse plane, perpendicular to the longitudinal direction. These curved portions can in particular delimit the junction zones between the first composite insert and the additional composite insert and allow the formation o