WO2008081218A1

WO2008081218A1 - Truck with mechanical actuator to move the steering wheel to a safety position

Info

Publication number: WO2008081218A1
Application number: PCT/IB2006/004189
Authority: WO
Inventors: Jérôme LAGRUT
Original assignee: Renault Trucks
Priority date: 2006-12-29
Filing date: 2006-12-29
Publication date: 2008-07-10
Also published as: JP2010514619A; JP5214629B2; EP2125488A1

Abstract

The truck comprises a mechanical actuator having a second part (60) directly rigidly fixed to a chassis (6) so as to be able to move the steering wheel from a driving position to a safety position using only the energy of a rearward motion of the driver cabin (4) relative to the chassis (6) caused by the frontal collision against the rear of a semi-trailer (70).

Description

TRUCK WITH MECHANICAL ACTUATOR TO MOVE THE STEERING WHEEL TO

A SAFETY POSITION

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a truck with mechanical actuator to move the steering wheel to a safety position..

BACKGROUND OF THE INVENTION

There exist trucks having:

- a chassis having driving wheels,

- a driver cabin mounted on the chassis so that in case of a frontal collision against the rear of a semi-trailer the cabin moves rearward relative to the chassis,

- a steering wheel, within the cabin, which is movable between a driving position wherein the steering wheel is closed to the driver so as to be easily grasped by the driver when driving, and a safety position wherein the steering wheel is far more away from the driver to reduce the risk or severity of injury of the driver in case of frontal collision,

- a steering column, within the cabin, mechanically connecting the steering wheel to a steering gear mounted on the chassis outside the cabin, and

- a mechanical actuator to move the steering wheel from the driving position to the safety position in response to the frontal collision, the mechanical actuator having a first part, within the cabin, rigidly fixed to the steering wheel or the steering column.

For example, a mechanical actuator is disclosed in DE-A-10 2004 048 177. In this document, the mechanical actuator is energized by the deformation of the front face of the driver cabin due to the frontal collision. This mechanical actuator works correctly in most of the situations.

However, when the truck collides with the rear part of a semi-trailer, it happens that the cabin is not much deformed but it mainly moves rearward relative to the chassis. In such a collision, the mechanical actuator of DE-A-10 2004 048 177 is not activated and the steering wheel is not moved to the safety position. Thus, the driver is projected against the steering wheel due to the abrupt deceleration and can be hurt by the steering wheel even if the front face of the cabin is not much deformed. SUMMARY OF THE INVENTION

Accordingly, it is an object of the invention to provide a truck which is safer. The invention provides a truck wherein the mechanical actuator has a second part rigidly fixed to the chassis outside the cabin so as to be able to move the steering wheel from the driving position to the safety position using only the energy of the rearward motion of the cabin relative to the chassis caused by the frontal collision against the rear of a semi-trailer..

When a frontal collision occurs with a semi-trailer rear, even if it happens that the front face of the driver cabin is not deformed much, the rearward motion of the cabin relative to the chassis occurs. Thus, with the above truck, the steering wheel is moved to the safety position and the driver is protected against injuries.

The embodiments of the above truck may comprise one or several of the following features: - the mechanical actuator comprising:

• at least one cable having the first part rigidly tied to the steering wheel or the steering column and the second part rigidly tied to the chassis, and

• bearings to convert a traction force that exerts on the second part due to the rearward motion of the driver cabin relative to the chassis into a traction force that exerts on the first part so as to move the steering wheel from the driving position to the safety position,

- the mechanical actuator has the first part and/or a third part directly fixed to the steering colum so as to move both the steering wheel and the steering column from the driving position to the safety position using only the energy produced by the rearward motion of the driver cabin relative to the chassis, the steering column being far more away from the driver in the safety position than in the driving position,

- the truck comprises at least an air-bag supported by the steering wheel, and the steering wheel has: • a rotation axis about which the driver rotates the steering wheel to drive the truck, the rotation axis defining an angle α with the driver cabin floor, • a transversal axis perpendicular to the rotation axis about which the steering wheel can rotate to adjust angle α under the control of the driver, and

• the mechanical actuator is able to automatically rotate the steering wheel about the transversal axis to decrease the absolute value of angle α when moving from the normal position to the safety position.

- the front part of the cabin that goes from a front face of the cabin bearing a front windscreen to the backside of a driver's seat is stiffer than a rear part of the cabin that goes from the driver's seat backside to a rear cabin face opposite to the front face whereby it is mainly the rear part that is deformed to absorb most of the frontal collision energy,

- the truck comprises cabin suspensions interposed between the cabin and the chassis which allows relative movement of the cabin with respect to the chassis in a vertical direction to absorb vibration due to the road, these suspensions being designed to allow a rearward motion of the cabin relative to the chassis of more than 15 cm to take place in case of the frontal collision against the rear of a semi-trailer. The embodiments of the truck present the following advantages:

- using a mechanical actuator made from cables and bearings allow for a better compactness than other possible mechanical actuators using for example rigid rods or the like,

- moving the steering column to a safety position also increases the driver security, using the transversal axis for both adjustment of angle α and moving the steering wheel in a position where the air-bag can be more efficiently deployed simplifies the truck manufacturing,

- using a front part of the cabin that is stiffer than the rear part increases the security of the truck by keeping the space where the driver is sitting nearly undeformed in case of a frontal collision, and

- using the suspensions interposed between the cabin and the chassis increases the driver's comfort and allow the rearward motion of the cabin relative to the chassis.

These and other aspects of the invention will be apparent from the following description, drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

- Figures 1 and 2 are a schematic diagrams of a first embodiment of a truck with a steering wheel in a driving position and in a safety position, respectively; - Figures 3 and 4 are schematic diagrams of a second embodiment of a truck with a steering wheel in a driving position and in a safety position, respectively.

In the drawings, the same reference numbers are used to designate the same elements. In the following description, well-known functions or constructions by a person of ordinary skill in the art are not described in details.

DETAILED DESCRIPTION OF SOME EMBODIMENTS Figure 1 shows a truck 2 having a driver cabin 4 mounted on a truck chassis 6 or truck frame.

Chassis 6 includes necessary equipments to displace truck 2 on a road. For example, chassis 6 includes:

- wheels 10,

- a motor 12 that rotates wheels 10, and - a steering gear 14 that can turn wheels 10 on the left or on the right to drive truck 2 in a curve. Cabin 4 includes:

- a driver seat 20,

- a steering wheel 22, - a steering column 24 that mechanically connects steering wheel 22 to steering gear 14.

In fact, steering wheel 22, steering column 24 and gear 14 are part of a steering assembly. This steering assembly also includes a steering shaft 25 that mechanically connect one extremity of steering column 24 to gear 14. Shaft 25 has one extremity within cabin 4 and one extremity outside cabin 4 which is connected to gear 14.

Steering column 24 is fixed to a dashboard.

Cabin 4 also presents a front face 28 that includes, for example, a windscreen 30 so that the driver can see the road. Cabin 4 also includes a rear face 32 that faces the rear of the truck 2 as well as a floor 36 that supports seat 20. Typically, floor 36 is roughly a plane which extends horizontally when truck 2 is on a horizontal road.

Cabin 4 is divided into a front part and a rear part. The front part is delimited from the rear part roughly by a vertical line 40 that crosses the backside of seat 20. The front part goes from line 40 to front face 28 whereas the rear part goes from line 40 to rear face 32.

The front part of cabin 4 is stiff er than the rear part. For example, this is achieved by using a mechanical structure to build the front part which is stiffer than the mechanical structure used to build the rear part. In figure 1 , this is illustrated by zones of the mechanical structure of cabin 4 which are thinner in the rear part than in the front part. These zones are encircled by dotted lines 42 and 44. An example of such a mechanical structure is disclosed in WO 2006/049536.

Cabin 4 is mounted on chassis 6 through the use of front and rear suspensions, respectively 46 and 48. Suspensions 46 and 48 allow a relative movement of cabin 4 with respect to chassis 6 essentially in a vertical direction to absorb vibrations due to displacement of truck 2 on a road. Suspensions 46 and 48 also allow a relative movement of cabin 4 relative to chassis 6 in a horizontal direction in case of frontal collision of truck 2 against the rear of a semi-trailer. For example, to this end, suspension 46 is designed to break in case of frontal collision.

In this embodiment, on the contrary, rear suspension 48 is designed to allow rearward motion of cabin 4 relative to chassis 6 in case of frontal collision but is not allowed to break in order to maintain cabin 4 on chassis 6 even in case of frontal collision. Suspensions 46 and 48 can be realized using elastic materials like rubber or using pneumatic suspensions.

Steering wheel 22 has a rotation axis 50 about which a driver 52 can rotate steering wheel 22 to drive truck 2 on the road.

In this embodiment, steering wheel 22 and steering column 24 can be moved from a driving position where driver 52 can easily grasp steering wheel 22 and rotates it about axis 50 to drive truck 2, to a safety position, illustrated in figure 2. In the safety position, steering wheel 22 and steering column 24 are far more away from seat 20 and driver 52 that in the driving position. In the safety position, steering wheel 22 and column 24 are crashed against front face 28. Finally, truck 2 also includes a mechanical actuator to move steering wheel 22 and steering column 24 from the driving position to the safety position. This mechanical actuator includes a cable 56 having one part 58 rigidly tied to steering wheel 22 and steering column 24 and another part 60 rigidly tied to chassis 6. For example, part 58 is rigidly fixed at the interface between column 24 and steering wheel 22. Part 60 is rigidly fixed to chassis 6 outside cabin 4. By "outside cabin 4", it is meant that part 60 is fixed to chassis 6 not through suspensions 46, 48 of cabin 4.

Parts 58 and 60 are rigidly fixed on a cabin side and a chassis side of suspensions 46, 48, respectively. Preferably, part 60 is fixed to chassis 6 to a place where displacement from the driving position to the safety position starts at the same time as cabin 4 starts to move rearward relative to chassis 6. For example, part 60 is fixed in front of a vertical line 62 which paths through the end of steering column 24 opposite to the end of column 24 which is mechanically connected to steering wheel 22. "Front" is defined in regard of the direction that goes from the rear to the front of the truck.

For example, in this embodiment, part 60 is fixed on the steering gear 14 which is in front of line 62.

The mechanical actuator also includes pulleys 66 to 68 to transform a horizontal traction force F₁ that exerts on part 60 into a traction force F2 that exerts on part 58. In this embodiment, pulley 66 is fixed to floor 36 near the interface between cabin 4 and steering gear 14.

Pulley 67 is fixed at the front face 28 in front of steering wheel 22 and steering column 24. Pulley 68 is fixed on steering column 24 so that the mechanical actuator can move column 24 from the driving position to the safety position. Figure 2 illustrates truck 2 after a collision against the rear of a semi-trailer

70. In such a collision, chassis 6 goes under the body of semi-trailer 70 so that cabin 4 moves rearward relative to chassis 6. As illustrated in figure 2, suspension 46 is broken whereas suspension 48 is not.

In such a collision, the rear part of cabin 4 is deformed to absorb the energy of the collision. Thus, as illustrated in figure 2, line 40 is much closer to the rear face 32 than in figure 1. Reversely, the front part of cabin 4 is nearly undeformed.

During the rearward motion of cabin 4 relative to chassis 6, a traction force F₁ is exerted on part 60. This traction force is converted through pulleys 66 to 68 into a traction force F₂ that exerts on part 58. Traction force F₂ moves steering wheel 22 and column 24 from the driving position to the safety position. In the safety position, steering wheel 22 and column 24 are much closer of front face 28 than in the driving position. Accordingly, in the safety position, steering wheel 22 and column 24 are also far more away from seat 20 and driver 52 so that the injury of driver 52 can be avoided.

Zigzag lines 80 and 82 just show that the rear part of cabin 4 has been deformed.

As it can be noted, the mechanical actuator that moves steering wheel 22 and column 24 from the driving position to the safety position is only energized by the rearward motion of cabin 4 relative to chassis 6.

Figure 3 illustrates a truck 90 which is similar to truck 2 except that:

- steering wheel 22 supports an air-bag 92 which is roughly placed at the center of steering wheel 22,

- steering wheel 22 includes a transversal axis 94 around which steering wheel 22 can be rotated under the control of driver 52, and

- a metal plate 96 extends radially from axis 50 towards seat 20.

For example, transversal axis 94 is fixed at the interface between column 24 and steering wheel 22. Axis 94 extends in a plan parallel to floor 36 and roughly perpendicularly to the direction of displacement of truck 90. The rotation of steering wheel 22 about axis 94 allows to adjust an angle α which is defined between axis 50 and a plan 98 parallel to floor 36. Accordingly, angle α can be adjusted by driver 52 to ensure a better comfort while driving truck 90.

The mechanical actuator able to move steering wheel 22 and column 24 from the driving position to the safety position is identical to the one described in figures 1 and 2 except that part 58 is directly fixed at the extremity of plate 96 the most far away from axis 50.

Figure 4 shows truck 90 after a collision with the rear of semi-trailer 70. The safety position of steering wheel 22 and steering column 24 is nearly the same as previously described in view of figure 2 except that the absolute value of angle α is decreased in the safety position. This allows a better deployment of air-bag 92. The tilting of steering wheel 22 about axis 94 is due to the fact that the mechanical actuator exerts a traction force on plate 96 at a position which is away from axis 50 and which is not perpendicular to axis 50. Accordingly, this traction force makes steering wheel 22 rotate about axis 94 so as to decrease the absolute value of angle α. In parallel, column 24 and steering wheel 22 are moved closer to front face 28 in the safety position than in the driving position in order to move far more away steering wheel 22 and steering column 24 from seat 20 and driver 52.

Obviously, what has been disclosed in the particular case of a collision against the rear of a semi-trailer, works also in case of a collision against any obstacle when the most rigid or most protuberant part of the obstacle is at a cabin high and not at a chassis high.

Many other embodiments are possible. For example, in another embodiment, in response to a frontal collision, the mechanical actuator is designed only to tilt steering wheel 22 so that air-bag 92 can deploy itself adequately without moving steering column 24. Part 58 can also be rigidly fixed to steering column 24 and not to steering wheel 22.

The front of cabin 4 need not to be stiffer than the rear of cabin 4 to implement the mechanical actuator disclosed herein. In the above embodiment, part 60 is not directly fixed on chassis 6 but on gear 14 which is directly fixed on chassis 6. In another embodiment, part 60 can be directly fixed on chassis 6. It may also be indirectly fixed to chassis 6 through other intermediate rigid parts than gear 14.

In the driving position, column 24 defines a a steering column axis that makes an angle β with floor 36. In the above embodiments, the steering column axis is merged with rotation axis 50. However, in some other embodiments, steering column axis is not merged with axis 50 so that angle α and angle β can be different.

In this last embodiment, angle β can also be adjustable.

In other embodiments, pulleys can be replaced by any kind of bearings. In another embodiment, part 60 can be tied to chassis 6 at a position behind line 62 if an additional pulley or bearing is directly fixed to chassis 6 in front of line 62.

LIST OF REFERENCES

2, 90 truck

4 cabin

6 chassis

10 wheel 12 motor

14 steering gear

20 seat

22 steering wheel

24 steering column

25 steering shaft

28 front line

30 wind screen

32 rear face

36 cabin floor

40 line

42, 44 stiffness reduced portion

46, 48 suspensions

50 rotation axis

52 driver

56 cable

58 first fixed part

60 second fixed part

62 line

66, 68 pulleys

92 air-bag

94 transversal axis

96 plate

98 horizontal plane

Claims

1. A truck comprising:

- a chassis (6) having driving wheels, - a driver cabin (4) mounted on the chassis (6) so that in case of a frontal collision against the rear of a semi-trailer the cabin (4) moves rearward relative to the chassis (6),

- a steering wheel (22), within the cabin, which is movable between a driving position wherein the steering wheel is closed to the driver so as to be easily grasped by the driver when driving, and a safety position wherein the steering wheel (22) is far more away from the driver to reduce the risk or severity of injury of the driver in case of frontal collision,

- a steering column (24), within the cabin, mechanically connecting the steering wheel (22) to a steering gear (14) mounted on the chassis (6) outside the cabin (4), and

- a mechanical actuator to move the steering wheel (22) from the driving position to the safety position in response to the frontal collision, the mechanical actuator having a first part (58), within the cabin, rigidly fixed to the steering wheel (22) or the steering column (24) wherein the mechanical actuator has a second part (60) rigidly fixed to the chassis (6) outside the cabin so as to be able to move the steering wheel from the driving position to the safety position using only the energy of the rearward motion of the cabin (4) relative to the chassis (6) caused by the frontal collision against the rear of a semi-trailer.

2. The truck according to claim 1 , wherein the mechanical actuator comprises:

- at least one cable (56) having the first part (58) rigidly tied to the steering wheel (22) or the steering column (24) and the second part (60) rigidly tied to the chassis (6), and

- bearings (66-68) to convert a traction force that exerts on the second part (60) due to the rearward motion of the driver cabin relative to the chassis into a traction force that exerts on the first part (58) so as to move the steering wheel from the driving position to the safety position.

3. The truck according to any one of the preceding claims, wherein the mechanical actuator has the first part/or a third part (68) directly fixed to the steering column (24) so as to move both the steering wheel (22) and the steering column (24) from the driving position to the safety position using only the energy produced by the rearward motion of the driver cabin relative to the chassis, the steering column (24) being far more away from the driver in the safety position than in the driving position.

4. The truck according to any one of the preceding claims, wherein: - the truck comprises at least an air-bag (92) supported by the steering wheel, and - the steering wheel has:

• a rotation axis (50) about which the driver rotates the steering wheel to drive the truck, the rotation axis defining an angle α with the driver cabin floor (36),

• a transversal axis (94) perpendicular to the rotation axis (50) about which the steering wheel can rotate to adjust angle α under the control of the driver, and

• the mechanical actuator is able to automatically rotate the steering wheel about the transversal axis (94) to decrease the absolute value of angle α when moving from the normal position to the safety position.

5. The truck according to any one of the preceding claims, wherein the front part of the cabin that goes from a front face (28) of the cabin bearing a front windscreen (30) to the backside of a driver's seat (20) is stiffer than a rear part of the cabin that goes from the driver's seat backside to a rear cabin face (32) opposite to the front face whereby it is mainly the rear part that is deformed to absorb most of the frontal collision energy.

6. The truck according to any one of the preceding claims, wherein the truck comprises cabin suspensions (46, 48) interposed between the cabin (4) and the chassis (6) which allows relative movement of the cabin (4) with respect to the chassis (6) in a vertical direction to absorb vibration due to the road, these suspensions (46, 48) being designed to allow a rearward motion of the cabin relative to the chassis of more than 15 cm to take place in case of the frontal collision against the rear of a semi-trailer.