GB2384215A - Vehicle bumper assembly with movable auxiliary bumper - Google Patents
Vehicle bumper assembly with movable auxiliary bumper Download PDFInfo
- Publication number
- GB2384215A GB2384215A GB0300645A GB0300645A GB2384215A GB 2384215 A GB2384215 A GB 2384215A GB 0300645 A GB0300645 A GB 0300645A GB 0300645 A GB0300645 A GB 0300645A GB 2384215 A GB2384215 A GB 2384215A
- Authority
- GB
- United Kingdom
- Prior art keywords
- vehicle
- predetermined speed
- bumper
- impact resistance
- deformable structure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D35/00—Vehicle bodies characterised by streamlining
- B62D35/005—Front spoilers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R19/00—Wheel guards; Radiator guards, e.g. grilles; Obstruction removers; Fittings damping bouncing force in collisions
- B60R19/02—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects
- B60R19/04—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects formed from more than one section in a side-by-side arrangement
- B60R19/12—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects formed from more than one section in a side-by-side arrangement vertically spaced
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R19/00—Wheel guards; Radiator guards, e.g. grilles; Obstruction removers; Fittings damping bouncing force in collisions
- B60R19/02—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects
- B60R19/18—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects characterised by the cross-section; Means within the bumper to absorb impact
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R19/00—Wheel guards; Radiator guards, e.g. grilles; Obstruction removers; Fittings damping bouncing force in collisions
- B60R19/02—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects
- B60R19/24—Arrangements for mounting bumpers on vehicles
- B60R19/38—Arrangements for mounting bumpers on vehicles adjustably or movably mounted, e.g. horizontally displaceable for securing a space between parked vehicles
- B60R19/40—Arrangements for mounting bumpers on vehicles adjustably or movably mounted, e.g. horizontally displaceable for securing a space between parked vehicles in the direction of an obstacle before a collision, or extending during driving of the vehicle, i.e. to increase the energy absorption capacity of the bumper
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R19/00—Wheel guards; Radiator guards, e.g. grilles; Obstruction removers; Fittings damping bouncing force in collisions
- B60R2019/007—Means for adjusting or regulating the crash absorption capacity of the vehicle, e.g. when detecting an impending collision
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R19/00—Wheel guards; Radiator guards, e.g. grilles; Obstruction removers; Fittings damping bouncing force in collisions
- B60R19/02—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects
- B60R19/18—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects characterised by the cross-section; Means within the bumper to absorb impact
- B60R2019/186—Additional energy absorbing means supported on bumber beams, e.g. cellular structures or material
- B60R2019/1873—Cellular materials
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
- B60R21/34—Protecting non-occupants of a vehicle, e.g. pedestrians
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
- Y02T10/82—Elements for improving aerodynamics
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Transportation (AREA)
- Body Structure For Vehicles (AREA)
- Superstructure Of Vehicle (AREA)
- Vibration Dampers (AREA)
Abstract
A motor vehicle 10 has a main bumper assembly 4 in which the crush resistance of a deformable structure 7 can be changed to optimise the impact performance of the bumper assembly 4 by displacing a movable impact resistance member 8 and an auxiliary bumper 20 which is movable from a retracted position to an extended position (fig 4). In the extended position the auxiliary bumper 20 can contact the lower leg of a pedestrian in the event of an impact therewith and tip the pedestrian onto a bonnet 12 of the vehicle 10. The auxiliary bumper 20 is movable to a lowered position when the vehicle is travelling at high speed to act as an aerodynamic aid.
Description
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A motor vehicle and a bumper assembly therefor
This invention relates to motor vehicles and in particular to a bumper assembly having improved pedestrian impact properties.
It is well known to provide a motor vehicle with a bumper assembly to absorb energy when the vehicle impacts against another object such as may occur if the vehicle is involved in a collision. The constraints placed upon a vehicle designer make the design of such bumper assemblies increasingly more difficult because of the need to satisfy several conflicting requirements. In many countries there is a requirement that for minor collisions up to approximately 8 KPH (5 mph) the bumper assembly must protect the vehicle with no permanent damage to its safety systems.
To achieve this, the designer is required to provide a deformable member with a relatively high crush resistance so that the deformation that occurs is minimal at these low speeds.
There is an increasing need to provide a more pedestrian friendly characteristic to the bumper assembly such that in the event of an impact of the vehicle with a pedestrian the injuries to the pedestrian are minimised. To achieve this it is desirable to provide a deformable member having a relatively low crush resistance so that a large amount of deformation will occur when impacted by a relatively small force of the magnitude corresponding to that of an impact with a pedestrian. At high speed the requirement is for a high crush resistance so that a large force is required to create deformation.
Prior art bumper assemblies as shown, for example, in WO-A-01/28818 utilise two components to try and achieve the above requirements, a deformable member which is normally made from foam or a plastic structure and a support
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structure in the form of a transverse beam. In addition, an auxiliary bumper is provided to ensure that in the event of an impact with a pedestrian an impact occurs with a lower portion of one or more legs of the pedestrian so that they are tipped onto a bonnet of the vehicle. This is advantageous as less injury will occur if the pedestrian is swept off of their feet in this manner rather than knocked over and potentially pass under the vehicle. Furthermore, the use of such a low mounted auxiliary bumper assists with the reduction of injuries to the knee joints of a pedestrian so impacted.
Such a prior art bumper assembly, however, has the disadvantage that the positioning of the auxiliary bumper has to be a compromise because of a need to maintain sufficient clearance with the road and also to provide a sufficient approach angle to the lower part of the vehicle so that inclines such as ramps can be negotiated without contact between the vehicle and the road.
It is an object of this invention to provide a motor vehicle with bumper assembly that is more readily optimised for all eventualities.
According to the invention there is provided a motor vehicle having a main bumper assembly positioned above an auxiliary energy absorbing bumper which is movable between at least a retracted position in which the auxiliary bumper has very little effect on the ground clearance of the motor vehicle and an extended position in which a front edge of the auxiliary bumper lies close to a vertical plane extending down from a front edge of the main bumper assembly wherein the main bumper assembly comprises a deformable structure to absorb energy in the event of an impact between the vehicle and another object and a support structure to transfer load from the deformable structure to a structural part of the motor vehicle and the deformable structure is
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configurable into a relatively low crush resistance condition and a relatively high crush resistance condition.
Preferably, the crush resistance of the deformable structure may be configurable based upon the speed of the vehicle.
The deformable structure may have a relatively high impact resistance below a first predetermined speed and a relatively low impact resistance above the first predetermined speed.
Preferably, the deformable structure may be configurable to have a relatively high impact resistance below a first predetermined speed and a relatively low impact resistance above. the first predetermined speed but below a second predetermined speed and has a relatively high impact resistance above the second predetermined speed.
The deformable structure may include at least one movable impact resistance member and one immovable energy absorbing member, in which case the crush resistance of the deformable structure may be changed by moving the or each movable impact resistance member from an extended position in which the impact resistance of the deformable structure is relatively high to a retracted position in which the impact resistance of the deformable structure is relatively low. The crush resistance of the deformable member may be determined by the combined crush resistance of the immovable impact resistance members when the movable impact resistance member is retracted.
Each movable crush resistance member may be movable by an electro-mechanical means, the electro-mechanical means may be a double acting cylinder.
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The movement of the or each movable crush resistance member may be controlled by an electronic control unit.
The position of the or each movable crush resistance member may be related to the forward speed of the vehicle, in which case the or each movable crush resistance member may be moved to a position such that the deformable structure has a relatively high impact resistance below a first predetermined vehicle speed and a relatively low impact resistance above the first predetermined vehicle speed. Preferably, and more particularly, the or each movable crush resistance member may be moved to a position such that the deformable structure has a relatively high impact resistance below a first predetermined vehicle speed and a relatively low impact resistance above the first predetermined vehicle speed but below a second predetermined vehicle speed and may be moved back to a position such that the deformable structure has a relatively high impact resistance above the second predetermined vehicle speed.
The position of the auxiliary bumper may be controlled by an electronic control unit.
The position of the auxiliary bumper may be related to the forward speed of the motor vehicle, in which case the auxiliary bumper may be moved to a retracted position below a first predetermined vehicle speed and may be moved to an extended position above the first predetermined vehicle speed. Alternatively, the auxiliary bumper may be moved to a retracted position below a first vehicle predetermined speed, an extended position between the first predetermined vehicle speed and a second predetermined vehicle speed and a lowered position above the second predetermined vehicle speed. The first predetermined speed may be in the range 6 to 10 kph and preferably 8 kph while the second predetermined speed may be in the range 60 to 100 kph and preferably 80 kph.
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The auxiliary bumper may be an aerodynamic device extending across a substantial part of the front of the vehicle, in which case the auxiliary bumper may be movable in a direction to increase its aerodynamic effect on the vehicle when it is moved to the lowered position.
The invention will now be described by way of example with reference to the accompanying drawing of which :-
Fig. 1 is a pictorial view of a first embodiment of a bumper assembly according to the invention;
Fig. 2 is a cutaway side view of a front portion of a motor vehicle according to the invention showing a cross section of a main bumper approximately along the line X-X on Fig. l and an auxiliary bumper in a first position;
Fig. 3 is a view similar to Fig. 2 but showing the auxiliary bumper in a second position;
Fig. 4 is a view similar to Fig. 2 but showing the auxiliary bumper in a third position;
Fig. 5 is a schematic view of a second embodiment of a motor vehicle assembly according to the invention showing main and auxiliary bumpers in one configuration; and
Fig. 6 is a view similar to Fig. 5 but showing the main and auxiliary bumpers in an alternative configuration.
With particular reference to Figs. 1 to 4 there is shown the front end portion of a motor vehicle 10 having an engine compartment cover or bonnet 12 and a bumper fascia 11. The vehicle 10 has a main bumper assembly 4 attached to a structural part of the vehicle via two longitudinally extending side rails 5 and an auxiliary energy absorbing bumper 20 pivotally attached to part of the vehicle structure by pivot means (not shown).
The main bumper assembly 4 comprises a deformable structure 7 and a support structure in the form of a transversely extending beam 6 which is used to connect the
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main bumper assembly 4 to the vehicle 10 and is bolted or riveted to the side rails 5. The deformable structure 7 comprises two distinct energy absorbing members, a first immovable energy absorbing member in the form of two spaced apart foam members 9 and three movable impact resistance members in the form of buffer members 8. It will be appreciated that other deformable structures could be used instead of the foam material such as a moulded plastic or honeycomb structures.
Each of the buffer members 8 is attached to a back plate 15 used to connect the buffer member 8 to a piston rod 14 forming an operable connection between the buffer 8 and a double acting cylinder 13. A piston (not shown) is slidably supported within the cylinder 13 and is attached to one end of the piston rod 14. The piston is movable in the cylinder 13 by supplying fluid to one or other end of the cylinder 13 so as to move the buffer 8 between an extended position as shown in Figs 1,2 and 4 and a retracted position as shown in Fig. 3. The buffer 8 is made from a foam material to provide an impact absorbing structure if impacted upon by another object. However, the buffer member 8 could be made as a crushable polymer or metal structure.
The auxiliary bumper member 20 is an aerodynamic device in the form of an air dam which extends across a substantial part of the frontal portion of the vehicle 10 and is shaped and configured to perform not only as an impact absorbing member but also as an aerodynamic aid. The bumper member 20 is made from a thin skin of a plastic material that is filled with foam so that in the event of an impact it acts as an energy absorbing member. Alternatively, the member 20 could be made as a moulding with the impact absorbing characteristics obtained as an inherent part of the mouldings design.
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The bumper member 20 is pivotally connected towards a rear edge to part of the structure of the vehicle 10 and is movable from a fully retracted position, as shown in Fig. 2, to an extended position, as shown in Fig. 3, and a lowered or aerodynamic position to increase its aerodynamic effect on the vehicle as shown in Fig. 4.
In the retracted position the bumper member 20 has virtually no effect on the ground clearance Cl and no effect on the approach angle of the vehicle 10.
In the extended position the bumper member 20 reduces the ground clearance to C2 and will have an effect on the approach angle of the vehicle 10. In this position the front edge of the bumper member 20 lies on a rearwardly inclined plane A-P and is in front of a vertical line A-Q extending down from the front edge of the main bumper assembly 4. This arrangement ensures that the front edge of the bumper member 20 will contact an object before the front edge of the main bumper assembly 4. In addition, the front edge of the bumper member 20 is vertically positioned such that in the event of a collision with a pedestrian it will impact upon a leg of the pedestrian above the ankle joint but well below the knee joint.
In the lowered position the bumper member 20 is positioned very close to the road surface and the ground clearance C3 is very small. This restricts the flow of air under the vehicle 10 and reduces aerodynamic lift on the front of the vehicle 10 and improves the drag coefficient of the vehicle.
The positions of the buffer members 8 and the auxiliary bumper 20 are controlled by an electronic control unit (not shown) in relation to the forward speed of the vehicle 10.
Below a predetermined speed in the range 6 to 10 kph, e. g. 8 kph, the electronic control unit is operable to place the
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buffers 8 in an extended position so that the impact or crush or impact resistance of the deformable structure 7 is relatively high and will place the auxiliary bumper member 20 in the retracted position. In this condition an impact with another object will result in little deformation of the main bumper assembly 4 and the impact will be taken primarily by the main bumper assembly 4. The retracted position of the auxiliary bumper 20 allows the vehicle 10 to be driven at such low speeds without there being a risk of contact between the ground and the auxiliary bumper 20. At such low speeds the flexibility in the bumper fascia cover 11 is sufficient to provide some protection in the event of an impact with a pedestrian and the relatively high resistance provided by the combined crush resistance and energy absorbing properties of the buffers 8 and the foam members 9 means that the overall crush resistance of the deformable structure 7 is sufficient to resist damage to the bumper assembly 4.
When the vehicle speed exceeds the first predetermined speed of 8 kph but is below a second higher predetermined speed in the range 60 to 100 kph, such as 80 kph, the electronic control unit is operable to retract the buffers 8 and move the auxiliary bumper member 20 to an extended position. While in this state an impact with another object will be resisted by the auxiliary bumper 20 and by the main bumper assembly 4. However, because the buffers 8 are retracted, the crush resistance of the main bumper assembly 4 is determined solely by the energy absorbing properties of the foam members 9 which are made of a low stiffness material and so provide a relatively low crush resistance.
Therefore, if the vehicle impacts a pedestrian in this state, then a relatively soft impact will occur but, more importantly, the auxiliary bumper 20 will make contact and will tend to tip the pedestrian onto the bonnet 12 of the vehicle 10. This is likely to cause less damage to a person
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than an impact with a rigid or stiff bumper assembly or if the pedestrian is pushed under the vehicle 10.
The electronic control unit is operable to place the auxiliary bumper member 20 into a lowered position and move the buffers 8 back to the extended position when the speed of the vehicle exceeds the second predetermined speed that is to say above 80 kph. In this condition the main bumper assembly 4 has a high crush resistance and the auxiliary bumper member 20 is in its most aerodynamic lift reducing position. This combination is beneficial to the occupants of the vehicle if an impact with another vehicle were to occur at such a high speed and also improves the stability of the vehicle 10 at high speed.
In the embodiment described above the auxiliary bumper member 20 is movable between three predetermined positions but it will be appreciated that the bumper member 20 could be moved in an infinitely variable manner between the retracted and lowered positions. For example the bumper member 20 could be retracted up to 10 kph and gradually be extended into the extended position as the speed increases from 10 to 20 kph and then remain in the extended position until the speed exceeds 80 kph at which point it will be gradually extended further into the lowered position if the speed of the vehicle continues to increase. It will be appreciated that the specific alignment of the main bumper assembly 4 and the auxiliary bumper 20 need not be perfectly vertical or with the auxiliary bumper 20 leading although such arrangements are preferable but it could be such that the auxiliary bumper is slightly behind the main bumper, the criterion for the positioning being that the combination must produce a dynamic contact situation with a pedestrian that encourages the pedestrian to be tipped over onto the bonnet.
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As an alternative to the previously described arrangement the buffers can be retracted once the speed exceeds the first predetermined speed and remain retracted so long as the speed is in excess of the first predetermined speed.
With particular reference to Figs. 5 and 6 there is shown a second embodiment of a motor vehicle according to the invention which is in many respects similar to that previously described. A front end portion of a motor vehicle 110 is shown having an engine compartment cover or bonnet 112 and a bumper fascia 111. The vehicle 110 has a main bumper assembly 104 attached to a structural part of the motor vehicle via two longitudinally extending side rails (not shown) and an auxiliary bumper 120 pivotally attached to part of the. structure of the motor vehicle 110 by two double acting actuators 121, 122. The main bumper assembly 104 comprises of a deformable structure 107 and a support structure in the form of a transversely extending beam 106. The beam 106 is used to connect the main bumper assembly 104 to the motor vehicle 110 and is bolted or riveted to the side rails.
The deformable structure 107 comprises two distinct energy absorbing members, a first immovable energy absorbing member in the form of two spaced apart foam members 109 and a movable energy absorbing member in the form of buffer member 108. It will be appreciated that other deformable structures could be used instead of the foam material such as a moulded plastic or honeycomb structures.
The buffer member 108 is attached to a piston rod 115 forming an operable connection between the buffer 108 and a double acting cylinder 113. The buffer 108 is made from crushable polymer or metal structure. A piston 114 is slidably supported within the cylinder 113 and is attached to one end of the piston rod 115. The piston 114 is movable
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in the cylinder 113 by supplying fluid to one or other end of the cylinder 113 via hoses 127 so as to move the buffer 108 between an extended position as shown in Fig 5 and a retracted position as shown in Fig. 6. A valve 125 is used to control the flow of fluid through the hoses 127 and hence the movement of the piston 114 and the buffer 108. The valve 125 is controlled by an electronic control unit 126.
The auxiliary bumper member 120 is an aerodynamic device in the form of aerofoil which extends across a substantial part of the frontal portion of the vehicle 110 and is shaped and configured to perform not only as an impact absorbing member but also as an aerodynamic aid. The bumper member 120 is made from a thin skin of a plastic material that is filled with foam so that in the event of an impact it acts as an energy absorbing member. The two actuators 121,122 moveably connect the bumper member 120 to part of the structure of the motor vehicle so that the bumper member 120 is movable from a fully retracted position, as shown in Fig. 5, to an extended position, as shown by the solid outline in Fig. 6, and a lowered or aerodynamic position as shown by the reference numeral 120a in Fig. 6.
The first actuator 121 is supplied with fluid via two hoses 130 controlled by a valve 123 connected to the electronic control unit 126 by a cable 129. The second actuator 122 is supplied with fluid via two hoses 131 controlled by a valve 124 connected to the electronic control unit 126 by a cable 128. It will be appreciated that not only can the actuators 121,122 move the bumper member up and down and forward and back but they can also vary the inclination of the bumper member 120 so as to vary its aerodynamic angle of attack and hence increase its aerodynamic effect on the vehicle 110.
In the retracted position the bumper member 120 has no effect on the ground clearance and no significant effect on the approach angle of the vehicle 110.
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In the extended position the bumper member 120 reduces the ground clearance and will have an effect on the approach angle of the motor vehicle 110. In this position the front edge of the bumper member 120 lies on a vertical line V-V extending down from the front edge of the main bumper assembly 104. This arrangement ensures that the front edge of the bumper member 120 will contact an object at the same time as or before the front edge of the main bumper assembly 104. In addition, the front edge of the bumper member 120 is vertically positioned such that in the event of a collision with a pedestrian it will impact upon a leg of the pedestrian above the ankle joint but well below the knee joint.
In the lowered position the bumper member 120a is positioned very close to the road surface and the ground clearance is very small. This improves the aerodynamic efficiency of the aerofoil 120a and increases the aerodynamic downforce on the front of the vehicle 110 and or the drag coefficient.
The positions of the buffer member 108 and the auxiliary bumper 120,120a are controlled by the electronic control unit 126 in relation to the forward speed of the vehicle 110. At speeds in the range 5 to 10 kph the electronic control unit 126 is operable to place the buffer 108 in an extended position so that the impact or crush resistance of the deformable structure 107 is configured to be relatively high and will place the auxiliary bumper member 120 in the retracted position. In this condition an impact with another object will result in little deformation of the main bumper assembly 104 and the impact will be taken primarily by the main bumper assembly 104. The retracted position of the auxiliary bumper 120 allows the vehicle 110 to be driven at such low speeds without there being a risk of contact between the ground and the auxiliary bumper 120.
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At such low speeds the flexibility in the bumper fascia cover 111 is sufficient to provide some protection in the event of an impact with a pedestrian and the relatively high resistance provided by the combined crush resistance and energy absorbing properties of the buffer 108 and the foam members 109 means that the overall crush resistance of the deformable structure 107 is sufficient to resist damage to the bumper assembly 104.
When the vehicle speed exceeds 10 kph the electronic control unit 126 is operable to retract the buffer 108 to configure the deformable structure 107 in a low crush resistance condition and also to move the auxiliary bumper member 120 into the extended position. While in this state an impact with another object will be resisted by the auxiliary bumper 120 and by the main bumper assembly 104.
However, because the buffer 108 is retracted, the crush resistance of the main bumper assembly 104 is determined solely by the energy absorbing properties of the foam members 109 which are made of a low stiffness material and so provide a relatively low crush resistance. Therefore, if the vehicle impacts a pedestrian in this state, then a relatively soft impact will occur but more importantly the auxiliary bumper 120 will tend to tip the pedestrian onto the bonnet 112 of the vehicle 110. This is likely to cause less damage to a person than an impact with a rigid or stiff bumper assembly or if the pedestrian is pushed under the vehicle 110.
The electronic control unit is operable to place the auxiliary bumper member 120,120a into its lowered position and move the buffer 108 back to the extended position above a predetermined speed such as 80 kph. In this condition the main bumper assembly 104 has a high crush resistance and the auxiliary bumper member 120 is in its most aerodynamic position to reduce lift and vehicle drag. This combination
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is beneficial to the occupants of the vehicle if an impact with another vehicle were to occur at such a high speed and also improves the stability of the motor vehicle at high speed.
It will be appreciated that the specific alignment of the main bumper and the auxiliary bumper need not be perfectly vertical or with the auxiliary bumper leading although such arrangements are preferable but it could be such that the auxiliary bumper is slightly behind the main bumper, the criterion for the positioning being that the combination must produce a dynamic contact situation with a pedestrian that encourages the pedestrian to be tipped over onto the bonnet.
Several electronic control units could be employed to control the valves 123,124 and 125 and that the or each electronic control unit will receive one or more signals from speed sensors (not shown) in order to determine the forward speed of the vehicle 110.
While the invention has been described with respect to specific embodiments, alternative arrangements or modification could be made without departing from the invention the scope of which is defined by the appended claims. For example, although the invention has been described with reference to the use of a double acting cylinder to vary the properties of the main bumper it will be appreciated that other means such as links or levers or other electro-mechanical means could be used to vary the stiffness. In addition the stiffness of the main bumper could be varied by any other suitable means such as for example controlling the flow of a fluid from a crushable container by a valve or by the use of rheological fluids with varying viscosity.
Claims (20)
1. A motor vehicle having a main bumper assembly positioned above an auxiliary energy absorbing bumper which is movable between at least a retracted position in which the auxiliary bumper has very little effect on the ground clearance of the motor vehicle and an extended position in which a front edge of the auxiliary bumper lies close to a vertical plane extending down from a front edge of the main bumper assembly wherein the main bumper assembly comprises a deformable structure to absorb energy in the event of an impact between the vehicle and another object and a support structure to transfer load from the deformable structure to a structural part of the motor vehicle and the deformable structure is configurable into a relatively low crush resistance condition and a relatively high crush resistance condition.
2. A motor vehicle as claimed in claim 1 in which the crush resistance of the deformable structure is configurable based upon the speed of the vehicle.
3. A vehicle as claimed in claim 1 or in claim 2 in which the deformable structure has a relatively high impact resistance below a first predetermined speed and a relatively low impact resistance above the first predetermined speed.
4. A motor vehicle as claimed in claim 1 or in claim 2 in which the deformable structure is configurable to have a relatively high impact resistance below a first predetermined speed and a relatively low impact resistance above the first predetermined speed but below a second predetermined speed and has a relatively high impact resistance above the second predetermined speed.
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5. A vehicle as claimed in any of claims 1 to 4 wherein the deformable structure includes at least one movable impact resistance member and at least one immovable energy absorbing member.
6. A vehicle as claimed in claim 5 wherein the crush resistance of the deformable structure is changed by moving the or each movable impact resistance member from an extended position in which the impact resistance of the deformable structure is relatively high to a retracted position in which the impact resistance of the deformable structure is relatively low.
7. A vehicle as claimed in claim 6 in which the crush resistance of the deformable member is determined by the crush resistance of the. immovable impact resistance members when the movable impact resistance member is retracted.
8. A vehicle as claimed in any of claims 5 to 7 in which the movement of the or each movable crush resistance member is controlled by an electronic control unit.
9. A vehicle as claimed in any of claims 5 to 8 in which the position of the or each movable crush resistance member is related to the forward speed of the motor vehicle.
10. A vehicle as claimed in claim 9 in which the or each movable crush resistance member is moved to a position such that the deformable structure has a relatively high impact resistance below a first predetermined speed and a relatively low impact resistance above the first predetermined speed.
11. A vehicle as claimed in claim 9 in which the or each movable crush resistance member is moved to a position such that the deformable structure has a relatively high impact resistance below a first predetermined speed and a
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relatively low impact resistance above the first predetermined speed but below a second predetermined speed and is moved back to a position such that the deformable structure has a relatively high impact resistance above the second predetermined speed.
12. A vehicle as claimed in any preceding claim in which the position of the auxiliary bumper is controlled by an electronic control unit.
13. A vehicle as claimed in any preceding claim in which the position of the auxiliary bumper is related to the forward speed of the motor vehicle.
14. A vehicle as claimed in claim 13 in which the auxiliary bumper is moved to a retracted position below a first predetermined speed and is moved to an extended position above the first predetermined speed.
15. A vehicle as claimed in claim 13 wherein the auxiliary bumper is moved to a retracted position below a first predetermined speed, is moved to an extended position between the first predetermined speed and a second predetermined speed and is moved to a lowered position above the second predetermined speed.
16. A vehicle as claimed in any of claims 10,11, 14 or in claim 15 wherein the first predetermined speed is in the range 6 to 10 kph.
17. A vehicle as claimed in claim 11 or in claim 15 wherein the second predetermined speed is in the range 60 to 100 kph.
18. A motor vehicle as claimed in any preceding claim in which the auxiliary bumper is an aerodynamic device
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extending across a substantial part of the front of the vehicle.
19. A vehicle as claimed in claim 18 when dependent upon claim 17 in which the auxiliary bumper is movable in a direction to increase its aerodynamic effect on the vehicle when it is moved to the lowered position.
20. A motor vehicle substantially as described herein with reference to Figs. 1 to 4 or Figs. 5 and 6 of the accompanying drawing.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GBGB0201199.7A GB0201199D0 (en) | 2002-01-19 | 2002-01-19 | A motor vehicle and a bumper assembly therefor |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB0300645D0 GB0300645D0 (en) | 2003-02-12 |
| GB2384215A true GB2384215A (en) | 2003-07-23 |
| GB2384215B GB2384215B (en) | 2005-05-11 |
Family
ID=9929368
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GBGB0201199.7A Ceased GB0201199D0 (en) | 2002-01-19 | 2002-01-19 | A motor vehicle and a bumper assembly therefor |
| GB0300645A Expired - Fee Related GB2384215B (en) | 2002-01-19 | 2003-01-13 | A motor vehicle and a bumper assembly therefor |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GBGB0201199.7A Ceased GB0201199D0 (en) | 2002-01-19 | 2002-01-19 | A motor vehicle and a bumper assembly therefor |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB0201199D0 (en) |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1541452A1 (en) * | 2003-12-10 | 2005-06-15 | C.R.F. Società Consortile per Azioni | A retractable aerodynamic-barrier device which can be pre-arranged underneath the floor panel of a motor vehicle, and a motor vehicle equipped with said device |
| FR2864811A1 (en) * | 2004-01-07 | 2005-07-08 | Renault Sas | Pedestrian protection device for motor vehicle, has shield surface enclosing shock absorber and flap which is moved between retracted position or high position and deployed position or low position |
| DE102004059747A1 (en) * | 2004-12-11 | 2006-06-14 | Volkswagen Ag | Pedestrian protection device in particular for vehicle with four wheel drive, comprising downwards extending unit behind front bumper |
| DE102005008029A1 (en) * | 2005-02-22 | 2006-08-24 | Daimlerchrysler Ag | Arrangement has protective element which is displaceable in vertical direction at front end of motor vehicle or rear of motor vehicle whereby slope angle of motor vehicle can be changed by displacement of protective element |
| DE102005030419A1 (en) * | 2005-06-30 | 2007-01-04 | Daimlerchrysler Ag | Motor vehicle with a Unterschutzeinrichtung |
| GB2513543A (en) * | 2013-02-08 | 2014-11-05 | Swift Group Ltd | Device for improving aerodynamics of vehicles |
| US8950800B1 (en) | 2013-11-11 | 2015-02-10 | Ford Global Technologies, Llc | Deployable lower leg stiffener for pedestrian protection |
| WO2015103437A1 (en) * | 2013-12-31 | 2015-07-09 | Tk Holdings Inc. | Active pedestrian protection system |
| WO2015081344A3 (en) * | 2013-11-29 | 2015-11-12 | Tk Holdings Inc. | Active lower leg engagement system |
| CN105793120A (en) * | 2013-11-29 | 2016-07-20 | Tk控股公司 | Active lower leg engagement system |
| GB2539975A (en) * | 2015-09-24 | 2017-01-04 | Ford Global Tech Llc | Deployable pedestrian safety device for vehicles |
| US9550464B2 (en) | 2013-12-30 | 2017-01-24 | Tk Holdings Inc. | Active knee protection system |
| WO2020239473A1 (en) * | 2019-05-29 | 2020-12-03 | Bayerische Motoren Werke Aktiengesellschaft | Deformation structure and pedestrian protection device having a deformation structure |
| WO2023224772A1 (en) * | 2022-05-17 | 2023-11-23 | Apple Inc. | Controlled panel deformation |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105873801A (en) * | 2013-12-31 | 2016-08-17 | Tk控股公司 | Active pedestrian protection system |
| DE102014207644A1 (en) | 2014-04-23 | 2015-10-29 | Bayerische Motoren Werke Aktiengesellschaft | Deformation element arrangement and motor vehicle with a deformation element arrangement |
| US10246036B2 (en) | 2017-06-30 | 2019-04-02 | Ford Global Technologies, Llc | Secondary bumper assembly |
| CN108163061A (en) * | 2017-12-15 | 2018-06-15 | 上海汽车集团股份有限公司 | Lift front-wheel choke system |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4778212A (en) * | 1986-04-19 | 1988-10-18 | Daimler-Benz Aktiengesellschaft | Motor vehicle front bumper molding with air spoiler |
| GB2336811A (en) * | 1998-04-25 | 1999-11-03 | Rover Group | A vehicle front impact arrangement |
| GB2341148A (en) * | 1998-06-26 | 2000-03-08 | Rover Group | A vehicle bumper arrangement |
-
2002
- 2002-01-19 GB GBGB0201199.7A patent/GB0201199D0/en not_active Ceased
-
2003
- 2003-01-13 GB GB0300645A patent/GB2384215B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4778212A (en) * | 1986-04-19 | 1988-10-18 | Daimler-Benz Aktiengesellschaft | Motor vehicle front bumper molding with air spoiler |
| GB2336811A (en) * | 1998-04-25 | 1999-11-03 | Rover Group | A vehicle front impact arrangement |
| GB2341148A (en) * | 1998-06-26 | 2000-03-08 | Rover Group | A vehicle bumper arrangement |
Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1541452A1 (en) * | 2003-12-10 | 2005-06-15 | C.R.F. Società Consortile per Azioni | A retractable aerodynamic-barrier device which can be pre-arranged underneath the floor panel of a motor vehicle, and a motor vehicle equipped with said device |
| FR2864811A1 (en) * | 2004-01-07 | 2005-07-08 | Renault Sas | Pedestrian protection device for motor vehicle, has shield surface enclosing shock absorber and flap which is moved between retracted position or high position and deployed position or low position |
| DE102004059747A1 (en) * | 2004-12-11 | 2006-06-14 | Volkswagen Ag | Pedestrian protection device in particular for vehicle with four wheel drive, comprising downwards extending unit behind front bumper |
| DE102004059747B4 (en) * | 2004-12-11 | 2016-02-11 | Volkswagen Ag | Safety device, in particular pedestrian protection device, for a motor vehicle, in particular for an off-road vehicle |
| DE102005008029A1 (en) * | 2005-02-22 | 2006-08-24 | Daimlerchrysler Ag | Arrangement has protective element which is displaceable in vertical direction at front end of motor vehicle or rear of motor vehicle whereby slope angle of motor vehicle can be changed by displacement of protective element |
| WO2007003328A1 (en) * | 2005-06-30 | 2007-01-11 | Daimlerchrysler Ag | Motor vehicle with an underprotection device |
| DE102005030419A1 (en) * | 2005-06-30 | 2007-01-04 | Daimlerchrysler Ag | Motor vehicle with a Unterschutzeinrichtung |
| GB2513543A (en) * | 2013-02-08 | 2014-11-05 | Swift Group Ltd | Device for improving aerodynamics of vehicles |
| US8950800B1 (en) | 2013-11-11 | 2015-02-10 | Ford Global Technologies, Llc | Deployable lower leg stiffener for pedestrian protection |
| CN105793120A (en) * | 2013-11-29 | 2016-07-20 | Tk控股公司 | Active lower leg engagement system |
| WO2015081344A3 (en) * | 2013-11-29 | 2015-11-12 | Tk Holdings Inc. | Active lower leg engagement system |
| US9365176B2 (en) | 2013-11-29 | 2016-06-14 | Tk Holdings Inc. | Active lower leg engagement system |
| US10421428B2 (en) | 2013-11-29 | 2019-09-24 | Joyson Safety Systems Acquisition Llc | Active pedestrian protection system |
| US9550464B2 (en) | 2013-12-30 | 2017-01-24 | Tk Holdings Inc. | Active knee protection system |
| WO2015103437A1 (en) * | 2013-12-31 | 2015-07-09 | Tk Holdings Inc. | Active pedestrian protection system |
| US9586555B2 (en) | 2013-12-31 | 2017-03-07 | Tk Holdings Inc. | Active pedestrian protection system |
| GB2539975A (en) * | 2015-09-24 | 2017-01-04 | Ford Global Tech Llc | Deployable pedestrian safety device for vehicles |
| GB2539975B (en) * | 2015-09-24 | 2017-05-17 | Ford Global Tech Llc | Deployable pedestrian safety device for vehicles |
| WO2020239473A1 (en) * | 2019-05-29 | 2020-12-03 | Bayerische Motoren Werke Aktiengesellschaft | Deformation structure and pedestrian protection device having a deformation structure |
| WO2023224772A1 (en) * | 2022-05-17 | 2023-11-23 | Apple Inc. | Controlled panel deformation |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0201199D0 (en) | 2002-03-06 |
| GB0300645D0 (en) | 2003-02-12 |
| GB2384215B (en) | 2005-05-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| 746 | Register noted 'licences of right' (sect. 46/1977) |
Effective date: 20061031 |
|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20210113 |