Motor vehicle and braking process

1. A motor vehicle comprising:

a crash detection device that detects an imminent collision between the vehicle and an obstacle;

a vehicle lifting device that cooperates with the crash detection device in order to compensate suddenly for a brake diving movement of the vehicle before the vehicle collides with the obstacle, wherein the vehicle lifting device includes a pushing body configured to engage with a road surface in order to compensate for the brake diving movement;

a safety belt system fitted with a belt tensioning device,

wherein the crash detection device causes the belt tensioning device to reduce belt slackness in the safety belt system dependent on a point in time at which the vehicle lifting device is activated,

wherein the crash detection device causes the belt tensioning device to activate the vehicle lifting device to reduce belt slackness with a time delay.

2. A motor vehicle comprising:

a crash detection device that detects an imminent collision between the vehicle and an obstacle;

a vehicle lifting device that cooperates with the crash detection device in order to compensate suddenly for a brake diving movement of the vehicle before the vehicle collides with the obstacle, wherein the vehicle lifting device includes a pushing body configured to engage with a road surface in order to compensate for the brake diving movement;

a safety belt system fitted with a belt tensioning device,

wherein the crash detection device causes the belt tensioning device to reduce belt slackness in the safety belt system dependent on a point in time at which the vehicle lifting device is activated,

wherein the belt tensioning device is designed such that it permits a two- or multi-stage reduction of belt slackness, and the crash detection device causes the belt tensioning device to effect a first reduction in belt slackness before the vehicle lifting device is activated and to effect a second reduction in belt slackness after the vehicle lifting device is activated.

3. A motor vehicle comprising:

a crash detection device that detects an imminent collision between the vehicle and an obstacle;

a vehicle lifting device that cooperates with the crash detection device in order to compensate suddenly for a brake diving movement of the vehicle before the vehicle collides with the obstacle, wherein the vehicle lifting device includes a pushing body configured to engage with a road surface in order to compensate for the brake diving movement;

a safety belt system fitted with a belt tensioning device,

wherein the crash detection device causes the belt tensioning device to reduce belt slackness in the safety belt system dependent on a point in time at which the vehicle lifting device is activated,

wherein the crash detection device causes the seat lifting device to activate the belt tensioning device with a time delay.

4. A motor vehicle comprising:

a crash detection device that detects an imminent collision between the vehicle and an obstacle; and

a vehicle lifting device that cooperates with the crash detection device in order to compensate suddenly for a brake diving movement of the vehicle before the vehicle collides with the obstacle, wherein the vehicle lifting device includes a pushing body configured to engage with a road surface in order to compensate for the brake diving movement,

wherein the vehicle lifting device includes an actuator that lowers the pushing body from a vehicle floor to the road surface to compensate for the brake diving movement,

wherein the vehicle lifting device or its actuator operates pyrotechnically, the actuator has a gas bag which lowers the pushing body when it unfolds, at least the underside of the pushing body facing the road surface is designed as a braking body and when it comes into contact with the road surface it transmits a braking force to the vehicle, or the vehicle lifting device compensates for the brake diving movement by lifting a front region of the vehicle.