Field of Invention

The present invention relates to a supported crash box with enhanced performance that is made of steel, and is located in the rear bumper, and absorbs the resulting impact energy in case of a rear end collision. Background of the Invention

Various safety systems are utilized to ensure the safety of both drivers and passengers in the event of a possible car accident. Such safety systems are categorized into two groups, namely active and passive safety systems. Passive safety stands for design measures, such as change of material and structural improvements, taken in relation to and applied on the vehicle in order to reduce the negative effects of the accident as much as possible in case of an accident. Both bumper and crash boxes (shock absorbers) located behind the bumper are among the passive safety system elements, which absorb the impact energy in the event of a crash of vehicles, and reduce the penetration of deformation to the driver and passenger compartments.

The shock-absorbing layer employed at the rear and in the front on land vehicles is called bumpers. They are located in both parts of the vehicle as the front bumper and the rear bumper. Bumper is one of the automobile parts whose primary task is to reduce the damage to vehicle and passengers in a possible calamity, aside from making the appearance of vehicle aesthetically pleasing. While varying according to each vehicle type, bumpers are generally manufactured from plastic and its variations. Bumper is developed in order to ensure minimization of damage to the body of vehicle by way of absorbing the impact force in case of an accident. Today, crash boxes are employed to absorb all or a part of the impact energy in low- and high-speed rear-end collision scenarios. Crash boxes are one of the connecting elements that are first to meet the impact in case of an accident involving front-end or rear-end crash and that absorb the resulting deformation energy, thus guaranteeing transmission of it into the automobile at the lowest possible level. Crash boxes have an important place in automobiles in terms of the task undertaken by them. In an attempt to increase the energy absorption capacity of crash boxes, several studies have been conducted by using variable parameters such as wall thickness, geometric properties, and the type of material used. However, the existing systems are insufficient in reducing the deformation on the vehicle body, particularly in low-speed crashes, and high- cost systems are preferred in such cases.

The European patent application document numbered EP3006311, an application in the state of the art, discloses a bumper structure for the front part of the vehicle body for small-scale collisions. The spacer of bumper structure is fixed to the projecting part with a nut. The spacer has a high flexural strength and ensures transmitting the lateral force to the power unit by deforming from the front side, without causing compression or bending.

The international patent application document numbered WO200324748, an application in the state of the art, discloses a vehicle bumper traverse comprising a crosspiece and two shock absorbers. Within the scope of development of the invention, it is aimed to minimize the possible damages caused by a low-speed crash. The bumper used for this invention may be either front or rear bumper. The absorber also comprises two clevises that are in the form of a trapezoid and in the shape of a flat plate. These clevises extend parallel to and at a certain distance from one another.

The South Korean patent application document numbered KR101238678, an application in the state of the art, discloses a bumper unit for vehicles. The said bumper structure should have a crash box and a shock-absorbing unit to absorb the impact energy. The shock absorber unit is placed in the crash box.

The South Korean patent application document numbered KR20140013635, an application in the state of the art, discloses a bumper having an energy-absorbing structure developed for vehicles. The purpose of bumper structure of that invention is to ensure that, in low-speed crashes and car-to-pedestrian collisions, the structure is suitable for re-use after meeting the impact energy, and that the pedestrian is not injured. For this purpose, it has a damper that absorbs the impact energy.

The South Korean patent application document numbered KR20160008427, an application in the state of the art, discloses a crash box in the bumper system of vehicles. Within the scope of this invention, the crash box has different steel plates that allow the TWB blank to be mutually pressurized on both ends and then be reformed. Front and rear mounting plates are assembled separately on the front and back parts of the box structure. This crash box configuration for vehicles is formed by bonding the front and rear mounting plates onto the bumper with bolts or by welding.

The South Korean patent application document numbered KR20150030118, an application in the state of the art, discloses a hybrid bumper traverse structure for vehicles. The inventive structure comprises a bumper traverse which is made of an aluminum extrusion material and has an installation space in a longitudinal direction on the center of the front, and a reinforcement traverse which is made of steel and is inserted into the installation space, and a crash box which is made of an aluminum extrusion material and is installed on both sides of the bumper traverse, and a mounting plate which is welded to each rear end of the crash box and is assembled to the vehicle body. Problems Solved by the Invention

An objective of the present invention is to provide a supported crash box that protects both vehicle and passengers by absorbing the resulting impact energy when the vehicle is rear-ended.

Another objective of this invention is to provide a supported crash box having an increased energy absorption capacity particularly in low-speed crashes and reducing bumper interference by allowing balanced transmission of force to the vehicle body.

Detailed Description of the Invention

The structure developed to achieve the objective of the present invention is illustrated in the accompanying figures, in which:

Figure 1. is a view of the traverse assembly in a mounted state.

Figure 2. is a view of the traverse assembly in a demounted state.

Figure 3. is a view of the supporting piece on one surface of the crash box in a mounted state.

Figure 4. is a view of the supporting piece in a demounted state.

The parts in the figures are each given reference numbers as follows:

1. Supported crash box

2. Crash box

21. Supporting piece

211. Front slot opening

212. Middle slot opening

213. Rear slot opening

214. Front comer indentation

215. Middle comer indentation 216. Rear corner indentation

217. Inner edge angled surface

218. Outer edge angled surface

219. Referencing slot

T. Traverse assembly

P. Traverse part

B. Connecting piece

A supported crash box (1); which is positioned in between and connected to the traverse part (P) located at the side facing the interior surface of the bumper and a connecting piece (B) of a traverse assembly (T) that is provided within a bumper positioned on the rear part of a vehicle and connected to the body of the vehicle on both ends with the connecting piece (B); comprises a crash box (2) and a supporting piece (21) positioned on the crash box (2) in order to increase absorption capacity and reduce bumper interference.

A supported crash box (1) of the present invention having increased energy absorption capacity especially in low-speed crashes reduces bumper interference by allowing balanced transmission of force to the vehicle body. For this purpose, a supported crash box (1) comprises supporting pieces (21) made of steel material that are attached to a lower-cost rear-end crash traverse assembly (T) and are positioned on the crash box (2). Supporting pieces (21) positioned on the lower and upper surfaces of a supported crash box (1) increase the energy absorption capacity of the crash box (2) and reduce bumper interference especially in low- speed crashes.

The traverse assembly (T) comprised of at least two supported crash boxes (1), a supporting piece (21) positioned on the lower and upper surfaces of the crash box (2), a traverse part (P), and at least two connecting pieces (B) is located within a bumper positioned on the rear part of a vehicle. Traverse part (P) extending along the inner surface of a bumper is connected to the body of the vehicle by means of the connecting pieces (B) positioned at both ends. The crash box (2), on the other hand, is positioned between a traverse part (P) and connecting pieces (B). It comprises at least two supporting pieces (21) positioned on the upper and lower surfaces of crash box (2), that, together with a traverse part (P), connecting pieces (B), and other elements of crash box (2), increase the energy absorption capacity of crash box (2), thereby preventing the deformation of the body, and ensure a balanced transmission of force to the vehicle body, thereby enabling to keep the bumper interference at targeted values, in the case of a RCAR structural low- speed crash.

Supporting pieces (21), which are connected on the lower surface of a crash box (2) facing the road and on the upper surface thereof exactly opposite to the said lower surface, are manufactured from steel with sheet cutting operation. A supporting piece (21) is connected from the edges by welding in a way to correspond to the lower and upper surfaces of the crash box (2) and with the help of referencing slots (219) formed on the supporting piece (21) in the middle and at the end facing the vehicle body.

Two supporting pieces (21) provided in each supported crash box (1), one on the left and one on the right at the rear of the vehicle, are connected symmetrical to each other on the lower and upper surfaces of the crash box (2). Front corner indentation (214) and outer edge angled surface (218) of the supporting piece (21) positioned on the upper surface and of the supporting piece (21) positioned on the lower surface, both having the same angular and dimensional forms, are positioned so as to face the exterior of the vehicle; while middle corner indentation (215) and inner edge angled surface (217) are positioned so as to face the interior of the vehicle.

On the supporting pieces (21) connected to the upper and lower surfaces of a crash box (2), there are structures and elements that aim to keep the relationship between stiffness and energy absorption capacity at an optimum level and to increase the energy absorption capacity. The said supporting pieces (21) have a flat structure with various openings and indentations. A front slot opening (211) positioned on the surface of a supporting piece (21) facing the traverse part (P) is positioned and sized to reduce the initial reaction force. A front comer indentation (214) positioned on the surface of a supporting piece (21) facing the traverse part (P) towards the exterior of the vehicle ensures that the initial folding of a crash box (2) is balanced. A middle slot opening (212) positioned in the middle of a supporting piece (21) guarantees that the energy is kept at an optimum level during collision. A middle corner indentation (215) positioned coaxially with the middle slot opening (212) on the surface of a supporting piece (21) facing the interior of the vehicle ensures that the second folding is balanced. A rear slot opening (213) positioned on the side of a supporting piece (21) facing the vehicle body enables that the maximum bumper interference is below the targeted value. Rear corner indentations (216), which are positioned coaxially with the rear slot opening (213) positioned on the side of a supporting piece (21) facing the vehicle body, on the surfaces of the supporting piece (21) facing both the interior and exterior of the vehicle, ensure that the final folding is balanced. Inner edge angled surface (217) is positioned on the side, facing the interior of the vehicle, of the surface, facing a part of the traverse part (P), of the supporting piece (21), connected to the upper and lower surface of a crash box (2) in order to increase its energy absorption capacity, and outer edge angled surface (218) is positioned on the side thereof facing the exterior of the vehicle. For balanced transmission of the collision force between the sides, facing the interior and exterior of the vehicle, of the supporting piece (21), the edge angles of the inner edge angled surface (217) and the outer angled surface (218) are proportioned to each other.

A front slot opening (211), a middle slot opening (212), and a rear slot opening (213) formed on the surface of a supporting piece (21) connected to the upper and lower surface of a crash box (2) have all different lengths from each other. The proportion between these lengths and the distance between a front slot opening (211), a middle slot opening (212), and a rear slot opening (213) are determined to provide optimum absorption.

A front corner indentation (214), a middle corner indentation (215), and a rear comer indentation (216) positioned on the edges, facing the interior and exterior of a vehicle, of a supporting piece (21) connected to the upper and lower surfaces of a crash box (2) have all different depths. The proportion between these depths and the distance between a front corner indentation (214), a middle corner indentation (215), and a rear corner indentation (216) ensure the balanced folding of the accordion structure and the stable behavior of a crash box (2).

A different customized traverse assembly (T) is used in every vehicle project due to design norms and performance requirements. Especially in low-speed RCAR structural tests, it is expected that the damage on the vehicle will be at a minimum level and the insurance costs will remain below the targeted value. High-cost rear- end collision systems such as composite, aluminum, and the like are used to achieve this goal. Thanks to a supported crash box (1) with the inventive supporting pieces (21), steel crash systems with a much lower cost are obtained and the goal is thus achieved. The present invention presents the opportunity to apply only one supported crash box (1) in all vehicle projects by way of customizing the elements on the supporting pieces (21) connected to the upper and lower surfaces of the said supported crash box (1). With the developed supported crash box (1), the cost is reduced by using a steel structure instead of a composite structure. Moreover, in the case that the same vehicle is to be sold in markets where RCAR low-speed structural testing is not required, only the lower and upper supporting pieces (21) are removed from a crash box (2), meaning that other safety performances are not compromised. This situation brings a significant cost advantage in terms of parts partnership. Thanks to the elements on the lower and upper supporting pieces (21) of a supported crash box (1), it can be produced in a single operation without the need for any operation relating to form and bending.