BUMPER ASSEMBLY AND MANUFACTURING METHOD THEREOF

Abstract

A bumper assembly is provided. The bumper assembly includes a back beam that is disposed within a bumper to absorb an external impact and a collision box that has a hollow tube shape. A first end portion of the collision box is coupled to the back surface of the back beam to receive an impact applied to the back beam and a plate is coupled to a second end portion of the collision box. In particular, the collision box is bonded with the back beam and the plate by an electro magnetic pulse technology method.

Claims

1. A bumper assembly, comprising: a back beam disposed within a bumper to absorb an external impact; a collision box having a hollow tube shape, a first end portion of which is coupled to a back surface of the back beam to receive an impact applied to the back beam; and a plate coupled to a second end portion of the collision box, wherein the collision box is bonded with the back beam and the plate by an electro magnetic pulse technology method.

2. The bumper assembly of claim 1, wherein an exterior surface of the collision box includes a bead implemented by the electro magnetic pulse tech. method.

3. The bumper assembly of claim 2, wherein the bead has a circular shape.

4. The bumper assembly of claim 2, wherein the bead has a linear shape.

5. The bumper assembly of claim 1, wherein the collision box has a rectangular cross-section.

6. The bumper assembly of claim 3, wherein the bead is formed on at least one of an upper surface, a lower surface, a first side surface, or a second side surface of the collision box.

7. The bumper assembly of claim 4, wherein the bead is formed on at least one of an upper surface, a lower surface, a first side surface, or a second side surface of the collision box.

8. The bumper assembly of claim 2, wherein an opening portion is formed on a front surface of the back beam at a position that corresponds to a rear surface to which the collision box is coupled.

9. The bumper assembly of claim 2, wherein the collision box is made of an aluminum material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other objects, features and advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0014] FIG. 1 shows a bumper assembly in the related art;

[0015] FIG. 2 shows a bumper assembly according to an exemplary embodiment of the present disclosure;

[0016] FIG. 3 is a partially enlarged view of FIG. 2 according to an exemplary embodiment of the present disclosure;

[0017] FIG. 4 shows a comparative example of a bumper assembly of the related art for comparison with an exemplary embodiment of the present disclosure; and

[0018] FIGS. 5 to 8 show exemplary embodiments of the bumper assembly according to the present disclosure.

DETAILED DESCRIPTION

[0019] To understand the present disclosure, the operational advantages of the present disclosure, and the objects attained by the practice of the present disclosure, reference should be made to the appended drawings illustrating the exemplary embodiments of the disclosure and the description in the accompanying drawings.

[0020] In describing an exemplary embodiment of the present disclosure, known techniques or repetitive descriptions that may unnecessarily obscure the essence of the present disclosure would be either reduced or omitted from the description thereof.

[0021] It is understood that the term vehicle or vehicular or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, combustion, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum).

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms a, an and the are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms comprises and/or comprising, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term and/or includes any and all combinations of one or more of the associated listed items.

[0023] FIG. 2 shows a bumper assembly of the present disclosure and FIG. 3 is a partially enlarged view of FIG. 2. Hereinafter, referring FIGS. 2 and 3, a bumper assembly and a manufacturing method thereof according to an exemplary embodiment of the present disclosure will be described in detail. A bumper assembly according to an exemplary embodiment of the present disclosure may include a back beam 10 disposed within the bumper to absorb an external impact; a collision (e.g., crash) box 20 of an inner hollow tube shape, a first end of which is coupled to the backside of the back beam 10 to receive the impact applied to the back beam 10; and a plate 30 coupled to a second end of the collision box 20.

[0024] In addition, an upper reinforcing plate 12 may be coupled to the upper side of the back beam 10. The collision box 20 of the present disclosure may be made of an aluminum material, and the collision box 20 may be coupled to the back beam 10 and the plate 30 by electro magnetic pulse tech., instead of being welded or bolted, to improve the manufacturing process and quality thereof. Furthermore, impact absorption performance may be improved by implementing the bead shape in the collision box 20 by the electro magnetic pulse tech.

[0025] Due to the improvement of the impact absorption performance by the collision box 20, an opening 11 may be formed on the front side of the back beam 10 at the position that corresponds to the rear side where the collision box 20 is coupled, and therefore, a closed cross-sectional surface structure may be unnecessary unlike in the related art, thereby reducing the weight and cost.

[0026] Flanges F may be formed at both ends of the collision box 20 for coupling the back beam 10 and the plate 30. In the present disclosure, the collision box 20 may be formed by electro magnetic pulse tech. to improve the impact absorption performance. To verify the collision absorption performance, a test specimen of the collision box of an A6063 material joined by electro magnetic pulse tech. with the back beam and the plate of an A1H01 material and another test specimen by melting welding (MIG) were fabricated, and tensile strengths thereof were tested. Table 1 shows the bond strength results for electro magnetic pulse tech. and Tables 2 and 3 are the results for melting welding.

TABLE-US-00001 TABLE 1 TEST Result value (N) TEST 1 (X1) 15251.39 TEST 2 (X2) 12815.66 TEST 3 (X3) 14118.48 TEST 4 (X4) 15070.66 TEST 5 (X5) 14158.62 Average 14282.96

TABLE-US-00002 TABLE 2 FILLET(overlap welding) Result value (kN) TEST 1 (X1) 11.34 TEST 2 (X2) 9.97 TEST 3 (X3) 10.00 TEST 4 (X4) 9.75 Average 10.27

TABLE-US-00003 TABLE 3 BUTT(overlap welding) Result value (kN) TEST 1 (X1) 6.87 TEST 2 (X2) 6.06 TEST 3 (X4) 6.26 TEST 4 (X4) 5.78 TEST 5 (X6) 6.77 Average 6.35

[0027] The test results show that bond strength may be improved by more than 40% compared to conventional melting welding (MIG). For melting welding, the base metal and the filler metal undergo a solidification process after melting, and a bond strength is lower due to accompanied coarsening of the microstructure. Conversely, the electro magnetic pulse tech. method is a solid state bond and may have high bond strength due to the work hardening phenomenon by plastic deformation of the base material due to high impact.

[0028] Based on the results of the test specimens, a prototype was manufactured and a collision test was performed with a truck to verify the performance of the specimen. Truck test condition is a truck speed of 10 Kph and a truck weight of 1,787 kg, and this is calculated as 75% of curb vehicle weight (CVW, 2,295 kg)+77.1 kg+10.5 kg. Barrier intrusion and beam deflection were measured under these conditions.

[0029] FIG. 4 and FIG. 5 are examples of prototypes for a verification experiment, FIG. 4 is an example of a bumper assembly of the related art for comparison with the present disclosure, and FIG. 5 to FIG. 8 are exemplary embodiments of the bumper assembly of the present disclosure. FIG. 4 shows a collision box 2 of steel material and shows a bead formed on the side surface of the collision box 2 and two line beads on one side surface, which conforms the North American mass production specification. A collision box 21 of FIG. 5 may be made of an aluminum material and without a bead, but may include a bumper assembly bonded by electro magnetic pulse tech. A collision box 22 of FIG. 6 may be made of an aluminum material with beads formed on both side surfaces and five line beads 22-1 formed on one side surface, and may include a bumper assembly bonded by electro magnetic pulse tech.

[0030] A collision box 23 of FIG. 7 may be made of an aluminum material with beads formed on both side surfaces and ten embossed beads 23-1 formed on one side surface, and may include a bumper assembly bonded by electro magnetic pulse tech. A collision box 24 of FIG. 8 may be made of an aluminum material with beads formed on both side surface, an upper surface and a lower surface, 15 embossed beads formed on one surface among the upper and lower surfaces and one side surface as shown in FIG. 8, and may include a bumper assembly bonded by electro magnetic pulse tech. Table 4 shows the measurement results of intrusion and deflection from the collision test.

TABLE-US-00004 TABLE 4 Analysis result values Comparative exemplary exemplary exemplary exemplary Example embodiment 1 embodiment 2 embodiment 3 embodiment 4 Target (FIG. 4) (FIG. 5) (FIG. 6) (FIG. 7) (FIG. 8) Item value STEEL No bead Line bead Embo 10 Embo 15 INTRUSION (mm) 110.5 110.5 107.6 107.6 108.6 108.0 DEFLECTION (mm) 67.4 67.4 64.4 64.5 64.5 64.4

[0031] As shown in Table 4, both intrusion and deflection may satisfy the target value in comparison with the comparative example. The intrusion amount of the intrusion barrier was improved by 2.6 mm compared to the comparative example, and the deflection amount of the deflection beam was improved by 3.0 mm compared to the comparative example.

[0032] According to the analysis result, the ability to absorb the collision energy may be improved more for the embossed bead, and in addition, a significant improvement may be obtained when uniformly formed on all of the upper and lower surfaces and both side surfaces. The deformation behaviors of the collision box 20 may be different depending on the direction of the applied load, and it is also due to the bond strength by the bond of electro magnetic pulse tech. compared to the conventional melting welding by welding. Moreover, the distal end portion of the collision box may be pre-cut to secure a maximum cross-section that may be bonded to the back beam and the plate to maximize the bonding area when bonding by the electro magnetic pulse tech.

[0033] Although the present disclosure has been described with reference to the drawings, it will be apparent to those skilled in the art that the disclosure is not limited to the exemplary embodiments set forth herein but that various modifications and variations may be made without departing from the spirit and scope of the present disclosure. Accordingly, such modifications or exemplary variations should fall within the scope of the claims of the present disclosure, and the scope of the present disclosure should be construed on the basis of the appended claims.