GB2517139A

GB2517139A - A side door for a motor vehicle

Info

Publication number: GB2517139A
Application number: GB1313460.6A
Authority: GB
Inventors: Duncan Stainer; Barry Grindle; Michal Jan Swiniarski
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2013-07-29
Filing date: 2013-07-29
Publication date: 2015-02-18
Also published as: DE102014214247A1; GB201407961D0; CN204077317U; GB201313460D0; GB2516723A

Abstract

A side door 10 for a motor vehicle 5 having an outer panel 12 and an elongate side impact member 11 mounted on an exterior panel 12 of the vehicle door 10. The side impact member is mounted in a longitudinal direction of the vehicle. The side impact member 11 comprises a stiff structural member to improve sensing of a side impact load by a side impact sensor. Preferably the stiff structural member is concealed from view by a body side moulding or may be part of a body side moulding. Also disclosed is a method suitable for controlling the activation of a safety system having at least one safety device forming part of the motor vehicle 5. The method comprising generating a signal indicative of a lateral acceleration in response to the application of an impact force to the stiff structural member, sensing the generated signal and deploying a safety device.

Description

A Side Door for a Motor Vehicle This invention relates to a side door for a motor vehicle and in particular to providing enhanced side impact sensing.

Safety systems in modern vehicles include a variety of devices such as seat belts and airbags which are designed to work together with sensors and other structural elements such as door beams and body panels. It is desirable to reduce any time delays between the moment of side impact and the initiation of deployment of components of the safety system suoh as airbags.

Japanese Patent Application JP-10315905 describes a side door in which a stiffening member is attached to an inner surface of the outer door panel in order to shorten the detection time of an impact acceleration due to a side impact on a side door.

Although such an arrangement is an improvement over previous such door arrangements having no reinforcement, the inventors have realised that further improvements can be made if the point at which initial impact occurs is moved further from a centre line of the motor vehicle.

It is an object of the invention to provide a side door for a motor vehiole which enhanoes side impaot sensing.

According to a first aspect of the invention there is provided a side door for a motor vehicle, the side door having an outer panel and an elongate side impact member mounted on the outer panel so as to extend in a lengthwise direction of the side door wherein the side impaot member comprises a stiff struotural member mounted on an outer surface of the outer panel to improve sensing of a side impact load by a side impact sensor.

The stiff structural member may be one of a reinforcing beam, a stiff elongate tube and a stiff box-section.

The stiff structural member may be a reinforcing beam having a lattice structure.

The lattice structure may comprise a number of horizcntally orientated cells that extend transversely with respect to a longitudinal axis of the side dcor.

The stiff structural member may be concealed frcm view by a body side mclding.

Alternatively, the stiff structural member may be formed as an integral part of a body side moulding.

According to a second aspect of the invention there is provided a motcr vehicle having a side door constructed in accordance with said first aspect of the inventicn.

According to a third aspect of the invention there is provided a method for controlling the activation of a safety system having at least one safety device forming part of a motor vehicle as claimed in claim 7 wherein the method comprises generating a signal indicative of lateral acceleration in response to the application of an impact fcrce tc the stiff structural member, sensing the generated signal and deploying a safety device when the sensed signal is indicative of a side impact.

The method may further comprise only activating the safety device if the magnitude of the sensed lateral acceleration exceeds a predetermined level of lateral acceleration indicative cf a side impact.

The invention will now be described by way of example with reference to the accompanying drawing of which:-Fig.la is a schematic side view of a motor vehicle according to a second aspect of the invention having a door according to a first aspect of the invention; Fig.lb is a schematic cross-section of the door on the chain dotted line x on Fig.la; Fig.2 is a pictorial side view of part a side door in accordance with a first embodiment of the first aspect of the invention; Fig.3 is a pictorial view in the direction of arrow A on Fig.2 showing a reinforcing member; Fig.4a is a pictorial view of a second embodiment of a side docr according to the first aspect of the invention; Fig.4b is a scrap cross-section through part of a side door having a reinforcing beam according to a third embodiment of the first aspect of the invention; and Fig.5 is a graph showing a predicted improvement in impact detection time at a side impact sensor achievable when using a door constructed in accordance with the first aspect cf the invention.

With reference to the Fig.1 there is shown a motor vehicle 5 having a body structure 6 including a pair of side doors 10 of which only the left hand side door 10 is shown.

The vehicle body structure includes an A-post 7 and a B-post 8.

The side door 10 has an inner panel 15 and an outer panel 12 defining therebetween a cavity bc.

The side door has a front end lOf and a rear end 1Cr both of whioh are structurally stiff in order to support look meohanisms and hinges (not shown) A stiff structural member or reinforcing member 11 is attached to an outer surface 13 of the outer panel 12 so as to extend substantially the entire length of the door 10 and span between the structurally stiff front and rear ends lofand 1Cr of the door 10. The stiff structural member 11 is covered by a resilient side moulding 14 so as to be obscured from view.

The motor vehicle 5 also includes a safety system including at least one safety device such as an airbag 20, a side impact sensor 16 mounted on the B-post and an electronic control module 17 operatively connected to the side impaot sensor 16 and the at least one safety devioe 20.

Such safety systems are well known in the art and will not be described in detail. Such a safety system is arranged to deploy one or more safety devices such as airbags and/ or restraint devices when a side impact is sensed to be occurring. It will be appreciated that the impact sensor could be of any particular type and is not limited to an acceleration sensor it could, for example, be a pressure sensor.

With reference to Figs.2 and 3 there is shown a first embodiment of the side door 10 in more detail.

The stiff structural member is in this case a rigid elongate metal tube 11 disposed on the outer surface 13 of the outer panel 12 of the door 10 between the outer surface 13 of the outer panel 12 of the door 10 and the body side moulding 14. The rigid elongate metal tube 11 is enclosed or encased within the body side moulding 14.

Operation of the safety system is as follows.

In the event of a side impact collision, when an object cones in contact with the side door 10, it will first contact the body side moulding 14 and the encased rigid elongate metal tube 11 located on the outer surface 13 of the outer panel 12.

As the rigid elongate metal tube 11 is deformed by the impact, a lateral acceleration corresponding to the speed and magnitude of the impact is generated. Due to the stiff nature of the rigid elongate metal tube 11, the magnitude of the lateral acceleration produced is greater than would be the case if the impact occurred against a non-reinforced outer panel. The resulting lateral acceleration is sensed by the side impact sensor 16 which produces a signal indicative of the side impact. The electronic control module 17 receives the signal from the side impact sensor 16 and deploys one or more safety devices such as the airbag 20 if predefined impact conditions are met. One of the predefined impact conditions is that the lateral acceleration exceeds a predefined threshold.

Without the rigid elongate metal tube 11, the soft outer panel 12 would have to be deflected considerably by the impacting object to produce reguired lateral acceleration indicative of an impact thereby resulting in a considerable delay in the sensing of the impact. Therefore, by using such a stiff structural member, the amount of deflection required to produce the required lateral acceleration is reduced thereby reducing this delay.

Advantageously, by positioning the stiff structural member on the outer surface of the outer panel further away from the vehicle centre line, the impact is sensed earlier.

This earlier sensing allows more time for the safety devices such as airbags to deploy before the encroachment of the impacting object into the passenger compartment.

A CAE model was used to predict the acceleration at the impact sensor using a steel box section reinforcing member of 24 mm thickness on an outer surface of an outer panel and an impact object travelling at Bm per second. The results from this model are shown in Fig.5. The curve 1 shows the acceleration without a reinforcing member/ stiff structural member and curve 2 shows the acceleration with a reinforcing member. A lateral acceleration of 8g was used in this case as the trigger level. This trigger level is predicted to be reached at 9 ms when using the stiff structural member fitted to an outer surface of an outer door panel compared to 12.1 ms without the stiff structural member.

Therefore a potential gain of 3.lms was predicted to be obtainable if such a reinforcing member were to be used.

This reduction in time to reach the trigger acceleration would facilitate earlier initial deployment of the safety devices such as the airbag 20 and provide more time for the airbag 20 to inflate or for other restraint devices to be tensioned.

With reference to Fig.4a there is shown a second embodiment of a reinforcing member which provides the same early detection of a side impact. In Fig.4a the side body moulding 14 has been cut-away in the region "R" to show an underlying reinforcing beam.

In the case of this second embodiment the stiff elongate tube is replaced by an elongate reinforcing beam 30 having a series of lattice like cell structures 31 to increase the stiffness of the elongate beam 30. The elongate reinforcing beam 30 is covered by a body side moulding 14 as previously referred to.

The lattice cell structures 31 are orientated so as to extend horizontally and normal to a longitudinal axis L-L of the elongate beam 30. That is to say, the cells 31 are aligned with a transverse axis of the motor vehicle 5.

The lattice cell structures 31 can be, for example and without limitation, rectangular, sguare, hexagonal, circular, elliptical or any other suitable shape.

As before, by positioning the elongate beam 30 on the outer surface 13 of the outer door panel 12 improves early detecticn of a side impact in the manner previcusly described.

Fig.4b shown a third embodiment of a reinforcing neuter having a lattice cell structure having number of horizontally arranged cells 131 extending in a transverse direction of the motor vehicle 5. As before, the reinfcrcing member 130 is located on an outer surface 13 of an outer panel 12 cf the side dcor and is in mcst respects the same as that shown in Fig.4a. The primary difference between this embodiment and the embodiment shown in Fig.4a is that the body side moulding and the reinforcing bean 130 are in this case made as a single unitary component.

Although the invention has been described with reference to its use on the front door of a two door motor vehicle it will be appreciated by those skilled in the art that it cculd be applied with similar advantageous effect tc a rear side door of a vehicle.

Similarly, the safety system described is only one embodiment of such a system and other types of safety system could be used with advantageous effect in combination with a side door constructed in accordance with this invention.

Although the impaot sensor in the given example is mounted on the B-post of the vehicle it will be appreciated that it could be mounted in other positions in close proximity to the location of the respective side door. For example and without limitation, if the side door is a front side door, the side impact sensor could be mounted on one of an A-post and a B-post of the motor vehicle. If the side door is a rear side door then the side impact sensor could be mounted on one of a B-post and a C-post of the motor vehicle.

It will be appreciated by those skilled in the art that although the invention has been described by way of example with reference to one or more embodiments it is not limited to the disclosed embodiments and that alternative embodiments could be constructed without departing from the scope of the invention as defined by the appended claims.

Claims

Claims 1. A side door for a motor vehicle, the side door having an outer panel and an elongate side impact member mounted on the outer panel so as to extend in a lengthwise direction of the side door wherein the side impaot member comprises a stiff structural member mounted on an outer surface of the outer panel to improve sensing of a side impact load by a side impact sensor.
2. A door as claimed in claim 1, wherein the stiff structural member is one of a reinforcing beam, a stiff elongate tube and a stiff box-section.
3. A door as claimed in claim 2 wherein the stiff structural member is a reinforcing beam having a lattice structure.
4. A door as claimed in claim 3 wherein the lattice structure comprises a number of horizontally orientated cells that extend transversely with respect to a longitudinal axis of the side door.
5. A door as claimed in any of claims 1 to 4 wherein the stiff structural member is concealed from view by a body side molding.
6. A door as claimed in any of claims2 to 4 wherein the stiff structural member is formed as an integral part of a body side moulding.
7. A motor vehicle having a side door as claimed in any of claims 1 to 6.
8. A method for controlling the activation of a safety system having at least one safety device forming part of a motor vehicle as claimed in claim 7 wherein the method -10 -comprises generating a signal indicative of lateral acceleration in response to the application of an impact force to the stiff structural member, sensing the generated signal and deploying a safety device when the sensed signal is indicative of a side impact.
9. A method as claimed in claim B wherein the method further comprises only activating the safety device if the magnitude of the sensed lateral acceleration exceeds a predetermined level of lateral acceleration indicative of a side impact.
10. A side door for a motor vehicle substantially as described herein with reference to the accompanying drawing.
11. A motor vehicle substantially as described herein with reference to the accompanying drawing.
12. A method for controlling the activation of an airbag of a vehicle substantially as described herein with reference to the accompanying drawing.