RU209347U1 - Shock-absorbing device for motor vehicles with composite sections in the form of a catenoid - Google Patents

Abstract

The utility model relates to the field of mechanical engineering, in particular to shock-absorbing devices for motor vehicles that implement a passive system for damping shock load damping. The disadvantages of the known technical solutions are the limited height/length of catenoid-shaped crashboxes, or the height/dimensions ratio of the base, on which it is impossible to fully realize all the potential possibilities of such a well-chosen form to reduce the energy level during impact and the use of exclusively negative Gaussian curvature of the surface shape and, as a result, a decrease in the effectiveness of shock absorption in the event of a potential impact. The proposed device allows you to increase the degree of energy level reduction during a collision, thereby either minimizing the degree of injury to participants in an accident: the driver, passengers of the vehicle, pedestrians in the case of use in the form of a crashbox or energy-absorbing barrier, or to preserve the functional properties of army armored vehicles in the case of using this form of crashbox in as elements for landing platforms. The technical result of the proposed utility model is the most effective reduction in impact energy during potential impact due to the use of a composite shell structure of alternating thin-walled shells close to the catenoid, positive and negative Gaussian curvature, as well as material savings compared to existing serial shock-absorbing inserts in the form of hollow thin-walled cylinders or parallelepipeds.

Description

The utility model relates to the field of mechanical engineering, in particular to shock-absorbing devices for motor vehicles that implement a passive system for damping shock load damping.

The prior art devices are known to dampen impact energy in collisions, in particular road traffic accidents (RTA), called crashboxes (also referred to as energy-absorbing inserts), mounted between the car side member and a rigid bumper beam, or platforms and "sandwich structures" on based on crash boxes used for landing heavy army armored vehicles or as part of energy-absorbing barriers. All the above devices are thin-walled shell structures or a set of them, mainly in the form of hollow thin-walled cylinders, parallelepipeds, six-octahedrons in the form of honeycombs (for example, JP 3007744, US 3841683, DE 19847743, DE 102016000599 A1, KR 20160033532 A, JP 2017124 CN 201810191809 A). However, these design solutions are not optimal from the point of view of either an insufficiently large value of the deformation path to dampen the speed during a vehicle collision, or the shape of the crashbox itself.

In addition, a crashbox in the form of a catenoid is known (patent RU 255871 C1, B60R 19/28, F16F 1/34 published on 07/10/2015) and utility model RU 175120 U1, B60R 19/28, published on 11/21/2017 - a prototype, which, by combining the advantages of thin-walled shells and the shape of the catenoid provide better damping parameters compared to the above design solutions.

However, the prototype also has disadvantages, which include:

1) the limited size ratio of the height / dimensions of the base of the catenoid itself, in which it is impossible to fully realize all the potential possibilities of such a well-chosen form of the damping object to reduce the energy level upon impact;

2) the use of exclusively negative Gaussian curvature. As you know, the crashbox on the vehicle is mounted between the side member and the bumper bar, due to which it has limited design dimensions for installation. In particular, the dimensions of the base of the crashbox in relation to the overall landing sites - on the spar and the bumper bar, cannot be wider than the cross sections of the latter. On platforms used for landing army armored vehicles or energy-absorbing barriers, as a rule, a honeycomb structure is used (crashboxes connected to each other), which also imposes restrictions on the dimensions of the product.

With such an arrangement of structural parts connected by the crashbox, it is impossible to fully realize the maximum possible length for the potential deformation of this shock-absorbing element, and also to use the range of strength properties of the connection laid down in the design, and, therefore, reducing the energy level when the impact load is perceived by the shock-absorbing device is not effective enough.

The objective of this utility model is to implement a more significant reduction in the energy level during impact by using a more significant amount of longitudinal deformation of the crashbox while maintaining its landing dimensions and shape features, in particular, the combination of positive and negative Gaussian curvature of the middle surface, which will most effectively minimize the consequences hit.

The technical result of the proposed utility model is the most effective reduction in impact energy during potential impact due to the use of a composite shell structure of alternating thin-walled shells of positive and negative Gaussian curvature of the middle surface close to the catenoid, as well as saving material compared to existing serial shock-absorbing inserts in the form of hollow thin-walled cylinders, parallelepipeds or six-octahedrons.

The technical solution of the proposed utility model is the use of a composite thin-walled shell structure of two shells, similar in shape to the catenoid, combining the positive and negative Gaussian curvature of the middle surface, which allows you to effectively and to the fullest extent use the length (height) of this composite energy-absorbing element for deformation due to collisions. That is, in addition to reducing the mass, it is possible to bring the ends of the crashbox closer together during its deformation (and in the composite structure of the energy-absorbing barrier also without significant loss of stability of the interconnected composite crashboxes), which will positively affect the value of the maximum deceleration and increase the energy intensity of the shockproof structure.

The utility model is illustrated in FIG. 1-3 showing: FIG. 1 - conventional crashbox in the form of a catenoid with geometric parameters: R - outer radius of a thin-walled shell; r is the inner radius of the thin-walled shell; H is the height of the crashbox; h - wall thickness of the crashbox; δ - maximum deviation of the middle layer from the landing clearance;

fig. 2 - a variant of the composite structure of the crashbox from two parts;

fig. 3 - a variant of conjugation of the proposed composite form of the crashbox.

Example of device operation. In case of potential collision with a fixed or moving obstacle, a crashbox or a structure in the form of an energy-absorbing barrier based on mated crashboxes begins to deform in the direction of the height H, while realizing the entire maximum possible length (height) of this composite energy-absorbing element; in this case, the process of reducing the consequences of impact includes both the increased length of the element due to the constituent parts, and the specific shape of the cross section, due to which the energy of elastic-viscous deformations increases and, as a result, the rigidity of the entire structure of the shock-absorbing device decreases.

Thus, the proposed device allows you to effectively and to the fullest extent ensure the damping of the shock load, increase the degree of energy level reduction during a collision and, thereby, either minimize the degree of injury to participants in an accident - the driver, passengers of the vehicle, pedestrians - in the case of use in the form of a crash box or energy absorbing barrier.

Literature

1. Shockproof device with passive damping system. RF patent for the invention No. 2555871. Published July 10, 2015 Bull. No. 19. Authors: Bogdanov V.V., Bogomolny V.M. Patentee: Federal State Budgetary Educational Institution of Higher Professional Education "Moscow State Engineering University (MAMI)". Open edition.

2. Vehicle crash box with oval base and catenoid shape. Description of the utility model to the patent RU 175120 U1. Published November 21, 2017 Bull. No. 33. Authors: Bogdanov V.V., Chabunin I.S. Patentee: Federal State State Military Educational Institution of Higher Education Military Educational and Scientific Center of the Ground Forces "Combined Arms Academy of the Armed Forces of the Russian Federation". Open edition.

Claims (1)

A shock-absorbing device with a passive damping system, mainly for motor vehicles, having a thin-walled shell shape, characterized in that the shell shape is a composite of two sections close in shape to the catenoid and combining positive and negative Gaussian curvature of the middle surface, and is made in the form of a composite set for single layer energy absorbing barrier.

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