GB2516723A

GB2516723A - A side door for a motor vehicle

Info

Publication number: GB2516723A
Application number: GB1407961.0A
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: 2014-05-06
Publication date: 2015-02-04
Also published as: GB201313460D0; GB2517139A; CN204077317U; GB201407961D0; DE102014214247A1

Abstract

A side door 10 for a motor vehicle (5, Figure 1 having a stiff structural reinforcing member 11 extending along an outer surface 13 of an outer panel 12 of the side door 10 in a longitudinal direction of the vehicle (5). The stiff structural member 11 is mounted on the outer surface 13 of the outer panel 12 of the side door 10 so as to be positioned adjacent the outer surface 13 of the outer panel 12 and is provided to aid early sensing of a side impact. The stiff structural member 11 being concealed from view by a body side moulding 14. A method for controlling the activation of a safety system is also disclosed where a signal indicative of a lateral acceleration is generated and sensed and a safety device is deployed when the signal is indicative of a side impact, preferably if the signal is above a predetermined threshold.

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 snch as seat belts and airbags which are designed to work together with sensors and other strnctural elements snch 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 such as airbags.

It is known from DE-A-4241382 to provide a side door for a motor vehicle with a body side moulding including part of a system for early detection of a side impact and a side impact member or door beam located within a cavity of the side door.

It is further known from Japanese Patent Application JP-10315905 to provide 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 the arrangement disclosed in JP-l0315905 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 with the reinforcement for the door is moved further from a centre line of the motor vehiole.

It is an object of the invention to provide a side door for a motor vehicle which enhances side impact 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 impact member comprises a stiff structurai member concealed from view by a body side moulding, the stiff structural member being mounted on the outer panel so as to be positioned adjaoent an outer surface of the outer panel.

It is an advantage of the invention that the mounting of the stiff structural member outboard of the outer surface of the outer panel aids early sensing of a side impact 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 horizontally orientated cells that extend transversely with respect to a longitudinal axis of the side door.

The side door may have a structurally stiff front end and a structurally stiff rear end and the stiff structural member may extend between the structurally stiff front and rear ends of the side door.

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 motor vehicle having a side door constructed in accordance with said first aspect of the invention.

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 from a sensor in response to the application of an impact force to the stiff structural member, sensing the signal generated by the sensor 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 of a side impact.

The sensor may be mounted remotely from the door.

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 embodiment of 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 second 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 part of a side door according to a third embodiment of the first aspect of the invention; Fig.4b is a scrap cross-section through part of a side door according to a fourth 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 of 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 1Cc.

The side door has a front end lOf and a rear end fOr both of which are structurally stiff in order to support lock mechanisms and hinges (not shown) A stiff structural member or reinforcing member 11 is attached to the side door 10 and is mounted on an outer surface 13 of the outer panel 12 so as to be positioned adjacent the outer surface 13 of the outer panel 12. The stiff structural member 11 extends substantially the entire length of the door 10 so as to span between the structurally stiff front and rear ends lOf and lOr of the side 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 capable of providing an output indicative of lateral acceleration mounted remotely from the side door 10 on the B-post and an electronic control module 17 operatively oonnected to the side impaot sensor 16 and the at least one safety device 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.

With reference to Figs.2 and 3 there is shown a second embodiment of the side door 10.

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 side 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 mounted on an outer surface 13 of the outer panel 12 so as to be positioned adjacent the outer surface 13 of the outer panel 12. The rigid elongate metal tube 11 is concealed from view by being enclosed or encased within the body side moulding 14 and extends along substantially the entire length of the side door 10 so as to span or extend between structurally stiff front and rear ends of the side door 10.

Operation of the safety system is as follows.

In the event of a side impact collision, when an object comes 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 cuter 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 indicative of lateral acceleration 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 required 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 and more time to decide whether the severity of the impact requires the deployment of all side impact safety devices or only some side impact safety devices if more than one type of safety device is provided.

A computer (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 8m 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 9ms when using the stiff structural member fitted to an outer surface of an outer door panel compared to l2.lms 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 third embodiment of the side door 10 having a reinforcing member which provides the same early detection of a side impact as those previously described. 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 embodiment the stiff elongate tube is replaced by an elongate reinforcing beam 30 positioned adjacent to and mounted on an outer surface 13 of the outer door panel 12. The elongate reinforcing beam 30 has 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 and extends along substantially the entire length of the side door so as to span or extend between structurally stiff front and rear ends of the side door.

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, square, 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 detection of a side impact in the manner previously described.

Fig.4b shows a fourth embodiment of the side door 10 having a reinforcing member 130. The reinforcing member 130 has a lattice cell structure comprising a number of horizontally arranged cells 131 extending in a transverse direction of the motor vehicle 5. As before, the reinforcing member 130 is located on an outer surface 13 of an outer panel 12 of the side door and is in most 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 beam 130 are made as a single unitary component.

In a further embodiment (not shown) an elongate side impact member comprises a stiff structural member in the form of a metal box section concealed from view by a decorative cover or coating which forms in combination with the metal box section a body side moulding. The stiff structural member is mounted on an outer panel of a side door so as to be positioned adjacent an outer surface of the outer panel and extends in a lengthwise direction of the side door. The metal box section extends substantially the entire length of the side door so as to extend between structurally stiff front and rear ends of the side door.

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 could be applied with similar advantageous effect to 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 impact sensor in the given example is mounted remotely from the side door on the B-post of the vehicle it will be appreciated that it could be mounted in other positions in close proximity but remotely to the location of the respective side door. That is to say, the impact sensor does not need to be mounted directly on the side door and could be a sensor used as part of another system of the motor vehicle such as, for example and without limitation, a dynamic chassis control system.

If the side door is a front side door, the side impact sensor could be mounted, for example and without limitation, on one of an A-post and a B-post of the motor vehicle and, if the side door is a rear side door then the side impact sensor could be mounted, for example and without limitation, 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

-10 -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 impact member comprises a stiff structural member concealed from view by a body side moulding, the stiff structural member being mounted on the outer panel so as to be positioned adjacent an outer surface of the outer panel.
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 in which the side door has a structurally stiff front end and a structurally stiff rear end wherein the stiff structural member extends between the structurally stiff front and rear ends of the side door.
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.

-11 -
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 comprises generating a signal indicative of lateral acceleration from a sensor in response to the application of an impact fcrce to the stiff structural member, sensing the signal generated by the sensor and deploying a safety device when the sensed signal is indicative of a side impact.
9. A method as claimed in claim 8 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 method as claimed in claim 8 or in claim 9 wherein the sensor is mounted remotely from the door.
11. A side door for a motor vehicle substantially as described herein with reference to the accompanying drawing.
12. A motor vehicle substantially as described herein with reference to the accompanying drawing.
13. A method for controlling the activation of an airbag of a vehicle substantially as described herein with reference to the accompanying drawing.