WO2009051551A1

WO2009051551A1 - Bracket for underrun protection and underrun protection

Info

Publication number: WO2009051551A1
Application number: PCT/SE2008/051152
Authority: WO
Inventors: Mats Engman; Mattias Månsson; Lukas Bures
Original assignee: Scania Cv Ab
Priority date: 2007-10-17
Filing date: 2008-10-08
Publication date: 2009-04-23
Also published as: SE0702331L; BRPI0816805B1; SE531582C2; BRPI0816805A2; DE112008002755T5; SE531582E; DE112008002755B4

Abstract

The invention relates to a bracket for underrun protection (6) for a vehicle (4), in which the bracket (8) comprises a first element (30), an intermediate second element (32) and a third element (34), the second element (32) being weaker than the other elements (30, 34), the first element (30) being rigidly fastened to an impact-absorbing unit (16) and articulatedly (A) fastened relative to the frame (12) of the vehicle (4), and the third element (34) being rigidly fastened relative to the frame (12) of the vehicle (4), the intermediate weaker second element (32) being also provided with a curvature (40) in a direction away from a steering device (18) situated near to the bracket, whereby in a collision the bracket (8) becomes deformed across the vehicle in a direction away from the steering device (18) so that the steerability of the vehicle (4) is not lost. The invention relates also an underrun protection (6) for a vehicle (4).

Description

BRACKET FOR UNDERRUN PROTECTION AND UNDERRUN PROTECTION

Technical field

The present invention relates to a bracket for underrun protection, and to underrun protection, for a vehicle.

Background

Heavy vehicles such as trucks often have a relatively high ground clearance at the front of the vehicle. This is a problem in a so-called "offset" collision in which the respective front corners of vehicles meet, or in a head-on collision with a lower vehicle, e.g. a passenger car which in a head-on collision or an offset collision may become wedged in under a truck, while at the same time the energy- absorbing zone at the front of the passenger car is so low that it does not absorb collision energy to the desired extent. The above problems have been solved by providing heavy vehicles which have high ground clearance with underrun protection so that, for example, a passenger car cannot run in under them and, at the same time, so that the collision energy-absorbing zone of the passenger car is utilised as intended.

Underrun protection as above usually comprises a beam situated low across the front of the vehicle and fastened to the frame of the vehicle by brackets. These brackets are adapted to becoming deformed in a collision while at the same time they absorb collision energy in order thereby further to protect persons in the passenger car.

SE 520 644 C2 refers to an underrun protection of the aforesaid kind which is adapted to becoming deformed and absorbing collision energy as a result of a beam bracket in the form of a tube becoming deformed in the longitudinal direction in a collision.

One problem is that in a head-on collision or an 'offset' collision between a passenger car and a heavy vehicle, the latter will usually continue travelling forwards even after the collision because it has more kinetic energy than the passenger car at the time of the collision, which means that an underrun protection which becomes deformed may block or affect the steering of the heavy vehicle so that the driver loses control of the steering after the collision and is thereby prevented from keeping the vehicle on the carriageway.

Brief description of the invention

The problem that an underrun protection might block the steering of heavy vehicles in a collision is solved according to the invention by a bracket according to claim 1 and an underrun protection according to claim 8.

A bracket according to claim 1 and an underrun protection according to claim 8 having the characteristics that the bracket comprises a first element, a intermediate weaker second element provided with a curvature in the direction across the vehicle in which it is desired that the bracket should move during deformation, and a third element, afford the advantage that the bracket of the underrun protection becomes deformed in a direction away from the vehicle's steering device so that its steerability is not lost after a collision.

Brief description of the drawings

The invention is described in more detail below with reference to the attached drawings, in which:

Fig. 1 depicts schematically a side view of a passenger car and a heavy vehicle which has an underrun protection with a bracket according to a first embodiment of the invention,

Fig. 2 depicts schematically a bracket for an underrun protection according to Fig. 1,

Fig. 3 depicts schematically an underrun protection with a bracket according to Fig. 1 before a collision, and Fig. 4 depicts schematically an underrun protection with a bracket according to Fig.l after a collision.

Description of preferred embodiments

Similar items in the various drawings bear the same reference notations.

Fig. 1 depicts schematically a side view of a passenger car 2 and a heavy vehicle 4 which has an underrun protection 6 with a bracket 8 according to a first embodiment of the invention. One end 10 of the bracket 8 is rigidly fastened relative to the frame 12 of the vehicle 4, preferably to the frame 12, and the other end 14 of the bracket 8 is rigidly fastened to an impact-absorbing unit 16, e.g. in the form of a beam, which extends substantially across the vehicle 4. The vehicle is further provided with a steering device 18, e.g. a steering linkage, a steering ball-joint or a steering gear, situated near to the front 20 of the vehicle. The impact-absorbing unit 16 is arranged at such a height above ground that the crash energy-absorbing zone 24 arranged at the front 22 of the passenger car 2 meets the impact-absorbing unit 16 in a head-on collision or an offset collision. Said height is adapted according to the legal requirements of the respective country but is usually of the order of 40 cm above ground or lower. In a collision, the crash energy will thus be partly absorbed by the crash energy-absorbing zone 24 of the passenger car 2 and partly by the underrun protection 6. The underrun protection 6 absorbs crash energy partly by the impact-absorbing unit 16 becoming deformed and partly by the bracket 8 of the underrun protection 6 becoming deformed. To keep the impact-absorbing unit 16 at the correct height throughout the course of a collision, the bracket 8 of the underrun protection 6 is also articulatedly fastened at an axis A which is fixed relative to the frame 12 of the vehicle. The axis A may for example comprise a screw 28 fastened in the frame 12 of the vehicle 4, preferably in a separate unit 26 fixed to the frame 12. In a collision, the impact-absorbing unit 16 and portions of the bracket 8 will thus move along a curve about the axis A, the shape of the curve depending on how the bracket 8 becomes deformed. Fig. 2 depicts schematically a bracket for an underrun protection 6 according to Fig. 1, which bracket 8 comprises at least a first element 30, an intermediate second element 32 and a third element 34, the second element 32 being weaker than the other elements 30, 34. The bracket 8 preferably takes the form of a single unit, e.g. a plate as depicted in the drawing, in which the bracket 8 comprises elements 30, 32, 34 which, by being part of one and same plate, are rigidly joined together as a single unit. The bracket 8 may alternatively comprise a number of separate elements 30, 32, 34 rigidly joined together to constitute a single unit, e.g. by welding or by mechanical connections such as riveted or threaded connections. The rigidity of the various elements 30, 32, 34 of the bracket 8 is preferably regulated by the more rigid elements 30, 34 of the bracket being provided with stiffenings. If the bracket 8 is a plate it is possible, for example, for stiffening variations 36, 38 of the cross-sectional shape of the elements 30, 34 to be made by pressing or stamping the plate in a press. Alternatively, the second element 32 may be made weaker by reducing its material thickness relative to that of the first element 30 and the third element 34. It is also preferable to provide a curvature 40, e.g. in the form of a pressed deformation initiator, in the material of the weaker second element 32, in the direction in which it is desired that the bracket 8 should move during deformation, thereby achieving controlled deformation of the bracket 8 in a collision, as described in more detail below. To further increase the rigidity of the more rigid elements 30, 32 it is possible, for example, for supporting bars 42 to be fitted between the bracket 8 and the frame 12 of the vehicle 4.

Fig. 3 depicts schematically an underrun protection 6 with a bracket 8 according to Fig. 1 before a collision. The bracket 8 comprises a first element 30, an intermediate second element 32 and a third element 34, the second element 32 being weaker than the other elements 30, 34. The first element 30 is rigidly fastened to the impact-absorbing unit 16 and articulatedly fastened, by a screw 28, relative to the frame 12 of the vehicle 4 about the axis A to a separate unit 26 fixed to the frame 12. Instead of a screw, it is possible, for example, to use a spigot or similar means about which the bracket can rotate. The third element 34 is rigidly fastened relative to the frame 12 of the vehicle 4. The intermediate weaker second element 32 is provided with a curvature 40 in the direction across the vehicle in which it is desired that the bracket 8 should move during deformation, so that in a collision the bracket 8 becomes deformed in a direction away from a steering device 18 situated close to the bracket, as illustrated in Fig. 4, so that the steerability of the vehicle 4 is not lost during the collision. In this case, the bracket 8 is also fastened to the frame 12 and/or in the impact-absorbing unit 16 by mechanical connections 44, 46 in the form of threaded connections.

Fig. 4 depicts schematically an underrun protection 6 with a bracket 8 according to Fig. 1 after a collision. It also depicts an impact-absorbing unit 16, the frame 12 of the vehicle 4 and a separate unit 26 which is fixed to the frame 12 and in which the bracket 8 is articulatedly fastened by a screw 28. As may be seen in the diagram, the bracket 8 has been deformed during the collision. The deformation has mainly taken place in the weaker element 32 of the bracket 8, which has become deformed in a direction away from the steering device 18 situated near to the bracket 8 as a result of the curvature provided in the bracket 8 as described in relation to Fig. 2. The fact that the bracket 8 has thus undergone controlled deformation during the collision means that the steerability of the vehicle 4 is not lost, so the driver can still steer the vehicle 4 after a collision and keep it on the carriageway. The impact-absorbing unit 16, as illustrated and as previously mentioned, has moved along a curve about the axis A, i.e. about the screw 28, with the result that the impact-absorbing unit 16 has remained at the correct height throughout the course of the collision.

The invention is described above for only one side of the vehicle. It is perfectly sufficient to only provide a bracket according to the invention on the side where the steering device is situated and to fit a bracket of some other kind on the other side of the vehicle. It is preferable that brackets according to the invention be each arranged, mirror image fashion, on their respective side of the vehicle to make it easier to fit the steering device in a collision-protected manner on either side of the vehicle, depending on whether the vehicle is made for a market with right or left hand drive.

The invention thus relates to a bracket for underrun protection 6 for a vehicle 4, in which the bracket 8 comprises a first element 30, an intermediate second element 32 and a third element 34, the second element 32 being weaker than the other elements 30, 34, the first element 30 being rigidly fastened to the impact- absorbing unit 16 and articulatedly fastened at A relative to the frame 12 of the vehicle 4, and the third element 34 being rigidly fastened relative to the frame 12 of the vehicle 4, the intermediate weaker second element 32 being also provided with a curvature 40 in a direction away from a steering device 18 situated near to the bracket, so that in a collision the bracket 8 becomes deformed across the vehicle in a direction away from the steering device 18 and the steerability of the vehicle 4 is therefore not lost.

The invention also relates to an underrun protection 6 for a vehicle 4.

The invention may be used on all kinds of heavy vehicles, such as trucks, buses and loaders.

The brackets are preferably made of steel plate and the impact-absorbing unit is preferably made of steel, but other materials suitable from the strength and deformation points of view may also be used for achieving said controlled deformation of the bracket in a collision.

As well as what has already been mentioned, i.e. the provision of underrun protection at the front of a vehicle, it may be provided also or alternatively at a rear portion of a vehicle or at one or more sides of a vehicle.

Claims

1. A bracket for underrun protection for a vehicle (4), in which the bracket (8) comprises a first element (30), an intermediate second element (32) and a third element (34), the second element (32) being weaker than the other elements (30, 34), characterised in that the first element (30) is rigidly fastened to an impact-absorbing unit (16) and articulatedly fastened relative to the frame (12) of the vehicle (4), and the third element (34) is rigidly fastened relative to the frame (12) of the vehicle (4), the intermediate weaker second element (32) being also provided with a curvature (40) in a direction away from a steering device (18) situated near to the bracket, whereby in a collision the bracket (8) becomes deformed across the vehicle in a direction away from the steering device (18) so that the steerability of the vehicle (4) is not lost.

2. A bracket for underrun protection according to claim 1 , characterised in that the bracket (8) comprises a single plate.

3. A bracket for underrun protection according to claim 2, characterised in that the rigidity of the various elements (30, 32, 34) of the bracket (8) is regulated by stiffening embossments (36, 38).

4. A bracket for underrun protection according to claim 2 or 3, characterised in that the curvature (40) takes the form of a pressed deformation initiator.

5. A bracket for underrun protection according to claim 1 , characterised in that the bracket (8) comprises separate elements (30, 32, 34) which are rigidly joined together to form a single unit.

6. A bracket for underrun protection according to any one of the foregoing claims, characterised in that the more rigid elements (30, 34) of the bracket (8) are provided with stiffenings.

7. A bracket for underrun protection according to any one of the foregoing claims, characterised in that the intermediate second element (32) is of smaller material thickness than the more rigid elements (30, 34) of the bracket (8).

8. An underrun protection for a vehicle, characterised in that the underrun protection (6) comprises an impact- absorbing unit (16) and at least one bracket (8) according to any one of the foregoing claims.

9. An underrun protection according to claim 8, characterised in that the underrun protection comprises an impact-absorbing unit (18) and at least two brackets (8) each arranged, mirror image fashion, on their respective side of the vehicle (4).

An underrun protection according to claim 8 or 9, characterised in that the impact-absorbing unit (16) is a beam.