Bumper beam and production method thereof

Abstract

The invention is related to an energy absorber which is suitable to be mounted into a bumper having metal parts and is produce from weight reduced composite material, characterized in that it comprises at least two external curvatures forming the front undulating surface, an internal curvature in connection with said external curvatures, at least a rear surface, two side surfaces, a bumper beam made of composite material having an inner support that forms three grooves between the external surfaces, the internal surface, the two side surfaces and rear surface, at least two crash boxes which absorb the energy transferred from the bumper beam during a collision, a bumper beam coupling part which enables to fix the bumper beam with each crash box, and a chassis coupling part which enables to fix each crash box to the vehicle chassis.

Claims

1. A bumper beam having high energy absorbing ability comprising a composite material, characterized in that it is produced by a pultrusion method using continuously weaved fibre reinforcement and plastic resin, the bumper beam comprising at least two external curvatures that form a front undulating surface, an internal curvature that is connected to the external curvatures, at least a rear surface, two side surfaces and an inner support which forms three grooves between said two side surfaces, rear surface, external curvatures and internal curvature.

2. The bumper beam according to claim 1, wherein the composite material is a carbon fibre reinforced composite material.

3. The bumper beam according to claim 1, wherein the composite material comprises thermoplastic resin.

4. The bumper beam according to claim 1, wherein the composite material comprises thermoset resin.

5. The bumper beam according to claim 1, wherein the composite material is a fibre glass reinforced composite material.

6. The bumper beam according to claim 1, wherein the composite material is an aramid reinforced fibre composite material.

7. The bumper beam according to claim 1, wherein the composite material is a Kevlar reinforced fibre composite material.

8. The bumper beam according to claim 1, wherein the composite material is a multi layer reinforced fibre composite material.

9. The bumper beam according to claim 1, wherein the composite material is a multi layer reinforced carbon fibre composite material.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 is the perspective view of the invention.

(2) FIG. 2 is the exploded perspective view of the invention.

(3) FIG. 3A is the perspective view of the bumper beam of the invention.

(4) FIG. 3B is the section view of the bumper beam of the invention.

(5) FIG. 4 is the perspective view of the invention which shows the direction of forces applied onto the bumper beam during collision.

(6) FIG. 5 is the section view showing the continuous winding during the production of the bumper beam.

DESCRIBING THE REFERENCE NUMBERS OF THE FIGURES

(7) 10. Energy absorber 20. Bumper beam 201. External curvature 202. Internal curvature 203. Side surface 204. Inner support 205. Rear surface  21. Groove 30. Crash box 301. Absorbing curve 302. Absorbing ridge 303. Flat surface 304. External curve  31. Bumper beam coupling part  32. Chassis coupling part 321. Part mounting curve x. Crash direction y. Transfer direction of the crash energy

DETAILED DESCRIPTION OF THE INVENTION

(8) In this detailed description the energy absorber and production method thereof, subject to the invention has been described by means of examples in order to further illustrate the invention, which do not have any kind of limiting effect on the invention.

(9) The subject of the invention is related to a bumper beam (20) and production method thereof which is formed of a bumper beam (20), crash box (30) and coupling parts, wherein the beam is coupled to the vehicle chassis that is placed between the body of the vehicle and the vehicle bumper and enables to reduce the energy by absorbing it during a collision.

(10) In FIG. 1, the isometric view of the energy absorber (10) constituted by the bumper beam (20), crash box (30) and the bumper beam coupling part (31) which forms the main body connections and the chassis coupling part (32) has been given.

(11) The bumper beam (20) made of composite material comprising at least two external curvatures (201) forming the front undulating surface, an internal curvature (202) in connection with said external curvatures (201), at least a rear surface (205), two side surfaces (203), an inner support (204) that forms three grooves (21) between the external surfaces (201), the internal surface (205), the two side surfaces (203) and rear surface (205), is characterized in that it comprises at least two crash boxes (30) which absorb the energy transferred from the bumper beam (20) during a collision, a bumper beam coupling part (31) which enables to fix the bumper beam (20) and each crash box (30), and a chassis coupling part (32) which enables to fix each crash box (30) to the vehicle chassis.

(12) The invention is characterized in that it is produced by a pultrusion method using continuously weaved fibre reinforcement and plastic resin, comprising at least two external curvatures (201) that form a front undulating surface, an internal curvature (202) that is connected to the external curvatures (201), at least a rear surface (205), two side surfaces (203) and an inner support (204) which forms three grooves (21) between said two side surfaces (203), rear surface (205) external curvatures (201) and internal curvature (202).

(13) In FIG. 2 the exploded isometric view of the bumper beam (20), the crash box (30) and the bumper beam coupling part (31) and the chassis coupling part (32) of said energy absorber has been given. The crash box (30) of the invention comprises an absorbing ridge (302) and absorbing curves (301) at the joining sections of said absorbing ridges (302). At the bottom and top section of the crash box, a flat surface (303) form is provided as it can be seen in FIG. 2. An external curve (304) that is concave is located at the joining section of said flat surface (303) and the absorbing ridge (302).

(14) In the preferred embodiment of the invention said crash box (30) has been produced from fibre reinforced composite material. In a preferred embodiment of the invention it is produced from carbon fibre reinforced composite material.

(15) In a preferred embodiment of the invention said crash box (30) can be produced from fibre glass, aramid fibre or Kevlar fibre. Said fibres can be used as continuous, chopped, woven or stacked.

(16) In the embodiments of the crash box (30) that are produced from composite material, either thermoplastic or thermoset resin is used.

(17) In a preferred embodiment of the invention said crash box (30) has been produced from metal material.

(18) In FIG. 3A, the perspective view of the bumper beam (20) of the invention and in FIG. 3B, the section view of the bumper beam (20) of the invention has been given. Said bumper beam (20) has at least three grooves (21) in its inner section. Said grooves (21) are formed by means of the inner supports (204) of the bumper beam (20). The bumper beam's (20) front section is in sinusoidal form. The detail of said form has been given in FIG. 3B. As it can be seen in the figure, a sinusoidal form is obtained by means of the internal curvature (202) that is placed between the two external curvatures (201) at the front section. In other preferred embodiments of the invention, the internal curvature (201) and the external curvature (202) numbers can differ and depending on this the continuation of the form can be provided. The rear section of the bumper beam (20) comprises a rear surface (205) shape tow which the bumper beam coupling part (31) is mounted. The side surfaces (203) form the edges of the bumper beam (20). Said side surfaces (203) are located at the top and bottom sections of the bumper beam (20) that is mounted onto the vehicle.

(19) The bumper beam (20) is produced preferably by the pultrusion method made of fibre reinforced composite material. In FIG. 5 the fibre weaved around the bumper beam (20) has been illustrated. The fibre is weaved continuously by means of the pultrusion method. Matrix material is formed by means of thermoplastic or thermoset resin and the production of the bumper beam (20) is completed. The fibre is weaved at a single direction during said winding process and preferably carbon fibre is used.

(20) In another preferred embodiment of the invention fibre is weaved in varying angles.

(21) In another preferred embodiment of the invention, a reinforcement material is formed using fibre glass, aramid fibre, or Kevlar fibre or a combination of said fibres. In other embodiments, said bumper beam (20) can be obtained by using continuous, chopped, woven or stacked fibre supports.

(22) As it can be seen in FIG. 2, the bumper beam (20) and the crash box (30) are fixed to each other by means of a bumper beam coupling part (31). The mounting of the crash box (30) with said bumper beam coupling part (31) is carried out by means of form fitting of the parts with each other. Said bumper beam coupling part (31) is produced from metal material, preferably from aluminium.

(23) In another preferred embodiment of the invention, the mounting of the crash box (30) with said bumper beam coupling part (31) can be carried out by close fitting of the parts to each other.

(24) The crash box (30) is fixed to the vehicle chassis by means of the chassis coupling part (32). The chassis coupling part (32) mentioned has a similar design to the surface form of the crash box (30). The part of the crash box is mounted to the structure formed by the absorbing ridge (302) and the absorbing curve (301) via the mounting curve (321). The mounting to the crash box (30) can be carried out by form fitting of the parts. Said chassis coupling part (32) is fixed to the vehicle chassis preferably using a bolt by means of the mounting slots of said coupling part. By this means the bumper beam (20) and crash box (30) which form the energy absorber (10) are mounted onto the vehicle. Said chassis coupling part (32) is produced from metal material, preferably from aluminium.

(25) In another preferred embodiment of the invention the chassis coupling part (32) and the crash box (30) can be obtained by adhering or close fitting of the parts to each other.

(26) The bumper beam coupling parts (31) and the chassis coupling parts (32) of the invention are produced by means of the machining method and they are resistant against the static loads that the bumper may be exposed to during a collision.

(27) In FIG. 4, the transfer direction (y) of the crash energy to the crash boxes (30) via the bumper beam (20) at the direction of the collision (x) has been shown. At the time of the collision the force received at the crash direction (x) by the bumper beam (20) is transferred to the two crash boxes (30). By means of the special shape of the crash boxes, energy is absorbed. The direction of a part of the crash force (x) received by the bumper beam (20) can be deviated by means of the three grooved (21) sinusoidal form and the energy is absorbed in a stepped manner with the crushing of the bumper beam (20).

(28) The energy absorber (10) which is a component formed of a bumper beam (20) and crash boxes (30) can be found by measuring the load formed during the impact to the heavy beam in the pendulum device and by calculating the area remaining below this force-displacement curve as energy, and by dividing this energy value to the weight of the part. The advantage energy transfer of the energy absorber (10) can be determined by a three point flexural test by applying force by means of hydraulic pistons to the frontal mid section of the part.