Impact absorbing element and method of assembly

Abstract

The invention relates to an impact-absorbing element and to an assembly method for a motor vehicle, said impact-absorbing element (1) absorbing energy in the event of a collision, having a metal tube (4) which forms a hollow chamber (6) and which is closed at the ends by a mounting plate (5) and an end wall (4a), characterized in that an insert (7) made of energy-absorbing plastic is arranged axially between the mounting plate (5) and the end wall (4a).

Description

TECHNICAL FIELD

[0001] The invention relates to an impact absorbing element for a motor vehicle, which absorbs energy in a crash, having a hollow metal tube, which is closed by a mounting plate on one end and a wall at the rear.

[0002] The invention also relates to a method for assembling the impact absorbing element. BACKGROUND

[0003] Bumpers are provided on each end of a motor vehicle, which are covered by a plastic shell on the vehicle frame. Deformation and impact absorbing elements are integrated within it to prevent damage to the vehicle body due to low speed impacts on the front or rear of the vehicle. The impact absorbing elements are usually thin-walled rectangular elements made of steel, aluminum or plastic. They can be produced by joining metal sheet parts together or by an aluminum extrusion process.

[0004] These impact absorbing elements, which are located between the chassis and the bumper, absorb the kinetic energy generated in a crash. This is to protect the chassis from permanent damage when the critical load is exceeded. These impact absorbing elements are usually adapted to the shape of the vehicle and its specific requirements. They must also comply with various regulatory requirements, taking into account the weight of the vehicle and the strength of the material. Therefore, these impact absorbing elements are individually customized for each type of vehicle. These impact absorbing elements can ideally absorb as much energy as possible without adding too much weight to the vehicle.

[0005] Impact absorbing elements exist in the prior art. WO2012040826A1 discloses a scalable impact absorbing element having a decagonal cross-section. The impact absorbing element is symmetrical with respect to a central axis.

[0006] Depending on the requirements for the vehicle in question, thick walls and long boxes can be used in the crash management system. Furthermore, due to structural limitations, only 90% efficiency can be obtained. If steel is used, thicker walls are heavier, while aluminum is expensive. It is not possible to achieve 100% energy dissipation efficiency.

[0007] Specifically for railway vehicles, a combination of materials is used.

[0008] EP2072370A1 discloses an impact absorber comprising a regenerative damper for impacts and tensions occurring during normal operation of the vehicle and a non-regenerative buffer element which converts at least a portion of the impact force on the impact absorber into heat energy and deformation energy when a predetermined critical impact force is exceeded. The damper can be made of rubber and is arranged between end plates. In this case, the energy absorption can be reversed.

[0009] The object of the invention is to create a better impact absorbing element for a motor vehicle, which meets the requirements regarding deformation and strength, without being too heavy. SUMMARY

[0010] This object is achieved by an impact absorbing element for a motor vehicle, which absorbs energy in a collision, which has a hollow metal tube, which is closed by a mounting plate on one end and by a wall at the rear, between which an insert made of energy absorbing plastic is arranged.

[0011] The combination of metal and plastic leads to a better impact absorbing element. By using plastic, it is possible to use a metal tube with a thinner wall, which reduces material consumption.

[0012] The cross section of the metal tube has at least four sides.

[0013] The metal tube can have various shapes.

[0014] The inserts are cylindrical. They can also have various cross sections.

[0015] The inserts have structures such as grooves and ring segments.

[0016] The ends of the inserts can be attached to the mounting plate and / or the end wall.

[0017] The inserts have a hole in the middle, into which a spike is pressed.

[0018] The inserts have a protrusion at their end, which engages in a corresponding recess in the mounting plate and / or the end wall.

[0019] The object is also achieved by a method for assembling an impact absorbing element, which comprises the following steps:

[0020] arranging an insert on the mounting plate and attaching it to the mounting plate,

[0021] arranging a metal tube on the mounting plate,

[0022] attaching the metal tube to the mounting plate,

[0023] closing the metal tube around the insert with an end wall.

[0024] The function of the metal impact absorbing element is improved by the energy absorbing plastic insert. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 An impact absorbing element mounted in the prior art is shown,

[0026] Figure 2 and Figure 3An impact absorbing element obtained by the invention is shown, and

[0027] Figure 4 and Figure 5 An exemplary insert is shown. DETAILED DESCRIPTION

[0028] Figure 1 The position where the impact absorbing element is mounted is shown. The impact absorbing element 1 is between the bumper 3 and the mounting plate 5. The mounting plate 5 forms a flange by which the impact absorbing element is attached to the chassis, not shown. Conventional impact absorbing elements with a square or rectangular cross section are often used because they can be easily manufactured. Impact absorbing elements with a polygonal cross section are increasingly popular because they are substantially stronger and more rigid. Figure 1 An octagonal impact absorbing element is shown which extends along an axial axis a. The impact absorbing element can have a plurality of sections which are formed by bending, rolling, stamping, pressing, drawing, hydroforming, molding, extruding, cutting and forging. The sections can be connected by welding, gluing, fastening or other conventional connection techniques, thereby forming a hollow chamber.

[0029] Figure 2 and Figure 3 An impact absorbing element 1 obtained by the invention is shown which consists of a metal tube 4 with an arbitrary cross sectional shape. In this exemplary embodiment four inserts 7 in the hollow chamber 6 in the metal tube 4 can be seen.

[0030] The inserts 7 extend from the mounting plate 5 to the end wall 4a on the metal tube 4. The inserts are cylindrical and made of energy absorbing plastic. The plastic can be treated in a way that influences the elasticity of the inserts 7. In this exemplary embodiment the inserts 7 have annular grooves 7a. The grooves can have different widths. The annular segments 7b between the grooves 7a can have the same or different lengths.

[0031] The ends 7d and 7c of the inserts 7 are supported on the end wall of the metal tube 4. Figure 4 A spike 8 is shown which is inserted into a hole 10 through the center of the insert 7. The spike influences the elasticity of the insert and can also be used to attach the end 7d to the mounting plate 5.

[0032] Figure 5 Another attachment means is shown schematically. The insert 7 has a protrusion 9 on the end 7d which is inserted into a corresponding hole in the mounting plate 5.

[0033] During assembly, all inserts 7 are first attached to or inserted into the mounting plate 5. Then, pre-fabricated metal tubes are placed on the inserts 7 and connected to the mounting plate 5. If there is any tension, the inserts 7 must also be attached to the end wall 4a. For this purpose, receivers or small profiles can be easily formed in the end wall.

[0034] The insert 7 can be attached to the mounting plate 5 in several ways. Examples include inserting the insert into the corresponding hole, or attaching it by means of a spike designed for this purpose, as described above.

[0035] Figure label:

[0036] 1. Impact Absorption Element

[0037] 3. Bumper

[0038] 4 tubes

[0039] 4a end wall

[0040] 5 Mounting Plate

[0041] 7 Inserts

[0042] 7a slot

[0043] 7b segment

[0044] 7c, 7d ends

[0045] 8 spikes

[0046] 9. Protrusion

[0047] 10 holes

Claims

1. An impact-absorbing element (1) for a motor vehicle, which absorbs energy in a collision, the impact-absorbing element having a metal tube (4) forming a hollow cavity (6) closed at both ends by mounting plates (5) and end walls (4a), characterized in that, An insert (7) made of energy-absorbing plastic is disposed axially between the mounting plate (5) and the end wall (4a).

2. The impact absorbing element (1) according to claim 1, characterized in that, The cross-section of the metal tube (4) has at least four sides.

3. The impact absorbing element (1) according to claim 1 or 2, characterized in that, The insert (7) is cylindrical.

4. The impact absorbing element (1) according to any one of the preceding claims, characterized in that, The insert (7) has a structure including a groove (7a) and a ring segment (7b).

5. The impact absorbing element (1) according to any one of the preceding claims, characterized in that, The ends (7c, 7d) of the insert (7) have means for attaching it to the mounting plate (5) and / or the end wall (4a).

6. The impact absorbing element (1) according to any one of the preceding claims, characterized in that, The insert (7) has a central hole (10) into which the spike (8) is pressed.

7. The impact absorbing element (1) according to any one of the preceding claims, characterized in that, The insert (7) has a protrusion (9) at its end (7c, 7d) that engages in a corresponding recess in the mounting plate (5) and / or end wall (4a).

8. A method for assembling an impact-absorbing element (1) according to any one of the preceding claims, comprising the following steps: Place the insert (7) on the mounting plate (5) and attach it to the mounting plate (5). The metal tube (4) is placed on the mounting plate (5). Attach the metal tube (4) to the mounting plate (5), and The metal tube surrounding the insert is sealed with its end walls.

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