This invention relates to a vehicle body for a commercial vehicle including a driver's cab mounted at least indirectly on a vehicle frame.
A vehicle body of this type is known, for example, from a configuration in which a driver's cab is mounted on a vehicle frame via a front pivot bearing. This driver's cab is additionally mounted on the vehicle frame via a rear driver's cab mounting, viewed in the vehicle longitudinal direction. This rear driver's cab mounting has a drive device with which the driver's cab can be tilted about the front pivot axis, for example for purposes of maintenance of the engine arranged below the cab.
A device for mounting a unit, for example a radiator, is known from German document DE 102 60 787 B3. The device is so designed that, in the event of an accident, the unit, i.e. for example the radiator, is moved in the direction of the rear of the vehicle and at the same time is lowered. By means of such a mounting, crash-box parts provided adjacent to the mounting can be deformed in an unobstructed manner.
Starting from the above, it is the object of the present invention to provide a vehicle body for a commercial vehicle which offers good passive safety in the event of a frontal impact.
This object is achieved according to the invention by having the driver's cab movable, by an impact force acting on the driver's cab from the front, in the vehicle longitudinal direction from an initial position to a deflected position, with the center of gravity of the driver's cab being arranged higher in the deflected position than in the initial position.
The mounting of the driver's cab according to the invention makes it possible to convert the kinetic energy arising in the event of a frontal impact into potential energy. Through the raising of the center of gravity of the driver's cab, large quantities of energy can be dissipated with comparatively small changes of the position of the center of gravity of the driver's cab.
An embodiment of the invention provides that the driver's cab is mounted on or fixed to at least one connecting element. The connecting element is mounted on the vehicle frame via a bearing. With such a connecting element, the movement path followed by the driver's cab in moving from the initial position to the deflected position can be defined especially well.
If the above-mentioned bearing between the connecting element and the vehicle frame is in the form of a pivot bearing, the connecting element can be swiveled from the initial position to a deflected position. The driver's cab is entrained as a result of the mounting on or fixing to the connecting element, and the center of gravity therefore is moved to a higher position.
Alternatively or additionally, the driver's cab may be mounted on the vehicle frame via at least one ramp or cam element. The ramp or cam element rises in the vehicle vertical direction when viewed from front or rear in the vehicle longitudinal direction. In this case the driver's cab is preferably mounted positively on the vehicle frame and is moved rearwardly along the ramp or cam element by the impact force acting on the driver's cab and simultaneously upwardly as a result of the rearwardly rising shape of the ramp or cam element. This movement from front to rear and at the same time from below to above converts kinetic energy into potential energy.
An especially advantageous embodiment of the invention provides that the movement of the driver's cab from the initial position to the deflected position is restrained by movement-restraining means. The movement-restraining means may be formed by the driver's cab, the connecting element, the ramp or cam element and/or the vehicle frame. However, they may also be formed by at least one additional component which comprises, for example, a cable, a sheet-metal element and/or a strap.
All or some of the components mentioned may be deformed during the movement of the driver's cab from the initial position to the deflected position. Depending on the design of the components, it can thereby be achieved that a deflection of the driver's cab from the initial position to the deflected position is triggered only when given impact forces are exceeded. After the movement of the driver's cab has been triggered, the deformation of the components serves to make possible additional dissipation of energy.
The components mentioned may also be in frictional engagement with a respective friction partner in order to be able to prevent triggering of the movement of the driver's cab from the initial position to the deflected position up to the attainment of predetermined impact forces and/or to dissipate energy with the aid of the frictional engagement after triggering of the movement. This energy dissipation takes place simultaneously with the energy dissipation accompanying the increase of the potential energy of the driver's cab.
An especially advantageous embodiment of the invention provides that destructible elements are provided which, in their undestroyed state, fix the driver's cab in the initial position and, in the destroyed state, make possible a movement of the driver's cab to the deflected position. With the aid of these destructible elements, the driver's cab can be retained securely on the vehicle frame provided a predetermined impact force is not exceeded. Upon exceeding of this predetermined impact force, the destructible elements are destroyed, whereby the driver's cab is released to move from the initial position to the deflected position. This movement may be accompanied by the deformations and/or frictional engagements discussed above.
If the bearing between the connecting element and the vehicle frame has a higher destruction resistance than the destructible elements, it is possible that, in the event of an impact of the driver's cab with an obstacle with only small impact forces, only the driver's cab and the destructible elements are affected, while the vehicle frame can remain undamaged. In this case only the destructible elements and the damaged parts of the driver's cab need to be exchanged. Shear pins may appropriately be used for such destructible elements.
According to a further aspect of the invention, deflection of the driver's cab from the initial position to the deflected position takes place in a plurality of stages. These states are associated, for example, with different deformation and/or frictional resistances, so that progressive dissipation of energy is made possible.
An especially preferred exemplary embodiment of the present invention is explained in more detail below with reference to the appended drawings.
The vehicle body 2 comprises a vehicle frame 4 on which a driver's cab 6, a portion of which is shown, is mounted.
The driver's cab 6 is mounted on the vehicle frame 4 via two plate-like connecting elements, a connecting element 12 arranged on the left-hand side, in the travel direction, being shown in the drawing. The following description applies correspondingly to the right-hand connecting element, in the direction of travel, which is not illustrated. The connecting element 12 has a bearing 14 in the form of a pivot bearing which connects the connecting element 12 swivelably to the vehicle frame 4. The bearing 14 includes a pin (not shown in detail) which is dimensioned sufficiently large to have high shear resistance. Two pins 16 and 18 are arranged forwardly of the bearing 14, in the vehicle longitudinal direction 8, and laterally adjacent thereto. Corresponding pins 20, 22 and 24 are provided at the upper end, in
The connection between the driver's cab 6 and the connecting element 12 is effected by a driver's cab bearing 26.
In the event of a collision with a rear end of another vehicle, for example a parked trailer platform, the driver's cab 6 is subjected to an impact load which is represented symbolically by an impact force 28 in
The distance hI of the center of gravity SI from the upper boundary of the vehicle frame 4, in the vehicle vertical direction 31, has increased to the distance hII in accordance with
The region into which the connecting element 12 swivels back from position I to position II is denoted by the reference symbol 42 in
Additionally, the connecting element 12 may be attached to the vehicle frame 4 by means of a cable. The cable is untensioned in the initial position I of the connecting element 12 and tensioned during the movement of the connecting element 12 to the deflected position II, whereby a part of the kinetic energy is dissipated through elongating deformation of the cable.
Number | Date | Country | Kind |
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102005034470.4 | Jul 2005 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP06/06709 | 7/8/2006 | WO | 00 | 6/11/2008 |