GB2584479A

GB2584479A - Exterior rear view mirror assembly

Info

Publication number: GB2584479A
Application number: GB1908069.6A
Authority: GB
Inventors: Nuti Nazario
Original assignee: Nissan Motor Manufacturing UK Ltd
Current assignee: Nissan Motor Manufacturing UK Ltd
Priority date: 2019-06-06
Filing date: 2019-06-06
Publication date: 2020-12-09
Also published as: GB201908069D0

Abstract

Provided is a wing mirror assembly 8 comprising an aerodynamically-shaped shell 12, a mirror within the shell 12, and an arm 10 for mounting the shell 12 to a vehicle 2. The mounting arm 10 has two perpendicular arm portions 16, 18, one of which is connected to an underside 22 of the shell 12, and the other is attachable to a vehicle door 14. Either, or both, of the arm portions have an aerofoil cross-section, which may have a positive angle of attach in the range +5 – + 10 degrees. The aerofoil elements reduce the pressure of the air flowing over the arm portions 16, 18, which diverts airflow away from the shell 12, thereby reducing the aerodynamic impact of the wing mirror assembly 8. Also provided is a vehicle 2 with the wing mirror assembly 8.

Description

EXTERIOR REAR VIEW MIRROR ASSEMBLY

TECHNICAL FIELD

The present invention relates to an exterior rear view mirror assembly for a vehicle. Aspects of the invention relate to the exterior rear view mirror assembly itself and a vehicle comprising the exterior rear view mirror assembly.

BACKGROUND

The presence of exterior rear view mirrors mounted on a vehicle is known to have an aerodynamic effect on the airflow around the vehicle body. In order to reduce the aerodynamic drag of the vehicle body it is known to enclose the mirror within a streamlined housing, which is defined by top, bottom, inboard and outboard side walls which converge to present a tapered shape to the oncoming airflow. Such streamlined housings typically comprise an aerofoil, or pear-shaped cross-section, that is arranged to reduce drag due to air turbulence in the wake of the mirror.

A mounting arm of the mirror housing is arranged to mount the mirror to a region of the vehicle body near the front A-pillar. The mounting arm typically forms a bridge between the inboard side wall of the mirror and an outboard surface of the vehicle body. When the vehicle is in forward motion, a substantial flow of air is deflected around the A-pillar on either side of the windscreen. This air flow is directed toward the mirror and then along the side of the vehicle. The mounting arm presents a bluff frontal shape to the oncoming airflow which deflects the stream in an uncontrolled manner thereby increasing the air resistance of the vehicle.

The mounting arm is configured such that the mirror is arranged at a distance from the vehicle body to provide the driver of the vehicle with a good line of sight. The separation between the mirror and the vehicle body defines a channel through which the oncoming airflow is directed. This arrangement of the mirror housing and mounting arm with respect to the body of the vehicle causes aerodynamic drag in the wake of the mirror. It also causes wind-noise which can be intrusive to vehicle occupants situated in the cabin of the vehicle.

Therefore, such rear view mirrors lead to an increase in the total air resistance of the motor vehicle. It is an aim of the present invention to address the disadvantages associated with the known rear view mirror assemblies.

SUMMARY OF INVENTION

According to an aspect of the invention there is provided an exterior rear view mirror for a vehicle, the mirror comprising a mirror housing comprising a forward facing aerodynamically shaped exterior shell terminating in a rearward trailing edge; a rearwardly facing reflecting surface mounted in the mirror housing; and, a mounting arm for connecting the mirror housing to the vehicle, the mounting arm comprising a first portion connectable to a door panel of the vehicle and configured to extend generally laterally therefrom and a second portion configured to extend generally vertically from the first portion when the first portion is connected to the door panel and connect to the underside of the mirror housing, wherein at least one portion of the first and second portions comprises a cross-sectional aerofoil element.

The arrangement of the mounting arm displaces the supporting structures of the mirror assembly away from the body of the vehicle, thereby improving the air flow around the mirror assembly whilst preserving the driver's line of sight. As a result, the arrangement of the mounting arm makes possible a significant reduction in the drag coefficient generated by the exterior rear view mirror assembly. The cross-sectional aerofoil element reduces the pressure of the oncoming air passing over the first portion of the mounting arm which pulls the airflow away from the mirror housing and thereby increases the aerodynamic efficiency of the mirror assembly.

The other portion of the first and second portions may comprise a cross-sectional aerofoil element.

The cross-sectional aerofoil element of the at least one portion of the first and second portions may be configured to have a positive angle of attack when the first portion is connected to the door panel.

The cross-sectional aerofoil element of the other portion of the first and second portions may be configured to have a positive angle of attack when the first portion is connected to the door panel.

The angle of attack of the cross-sectional aerofoil element of the first portion and/ or the second portion may be between +5 and +10 degrees.

At least part of the underside of the mirror housing may comprise a concave profile.

The concavity of the concave profile may be substantially equivalent to the upper camber of the cross-sectional aerofoil element of the first portion such that the height of at least a section of the channel defined between the underside of the mirror housing and the upper surface of the first portion is uniform.

The concavity of the concave profile may be configured such that the height of at least a section of the channel defined between the underside of the mirror housing and the upper surface of the first portion decreases in a longitudinal direction from a leading to a trailing edge of the mirror housing According to a further aspect of the invention there is provided a vehicle comprising an exterior rear view mirror assembly according to any of the preceding paragraphs.

The first portion of the exterior rear view mirror assembly may be connected to the door panel at a position lower than an intersection between the windscreen pillar and front wing of the vehicle.

A contour of the vehicle in a region below the intersection between the windscreen pillar and the front wing may be configured to deviate in an inboard direction to form at least a section of the channel defined between the mirror housing and the vehicle.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 illustrates a perspective view of an exterior rear view mirror assembly according to an embodiment of the present invention; Figures 2 and 3 are forward and plan views, respectively, of the mirror assembly shown in Figure 1; Figure 4 is a plan cross sectional view of a mounting arm of the mirror assembly of Figure 1; and, Figure 5 illustrates a schematic cross section of an aerodynamic element of the mounting arm of the mirror assembly shown in Figure 4.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice the invention. Other embodiments may be utilised, and structural changes may be made without departing from the scope of the invention as defined in the appended claims. Moreover, references in the following description to "upper", "lower", "front", "back" and any other terms having an implied orientation are not intended to be limiting, and only refer to the orientation of the features as shown in the accompanying drawings.

The present invention relates to an exterior rear view mirror assembly comprising a mirror housing and a mounting arm, which functions as a supporting structure for holding the mirror housing in a fixed position relative to the vehicle to which the mirror assembly is connected. The mounting arm comprises a substantially L-shaped configuration which connects the underside of the mirror housing with an exterior door panel of the vehicle.

This arrangement displaces the supporting structure of the mirror assembly away from areas of the vehicle in which strong flow structures develop, thereby preventing any adverse interaction therewith. As a result, the arrangement of the mounting arm makes possible a significant reduction in the drag generated by the mirror assembly comparative with conventional mirror assemblies.

FIG. 1 illustrates a front left wing of a vehicle 2 comprising a windscreen pillar 4, which supports a roof, and also forms an intersection between a windscreen 6 and a door 14 of the vehicle 2. An exterior rear view mirror assembly 8 is shown having a mounting arm 10 which is arranged to connect a mirror housing 12 of the mirror assembly 8 to an exterior panel 38 of the door 14.

The mirror housing 12 is conventional in that it comprises top and bottom walls 20, 22, generally aligned with the respect to the lateral axis of the vehicle 2, and inboard and outboard side walls 24, 26, which are generally aligned with a vertical axis of the vehicle 2.

The top and bottom walls 20, 22 and the inboard and outboard side walls 24, 26, all converge toward the front of the mirror housing 12 to form a forward facing aerodynamically shaped exterior shell that terminates at a rearward trailing edge 28 that defines the perimeter of an opening in which a mirror plate is mounted. The forward most section of the exterior shell defines the leading edge 29 of the mirror housing 12.

The mirror plate comprises a metallised glass substrate which forms a rearwardly facing reflecting surface. The mirror plate is arranged so that the reflecting surface is visible to the driver in order to provide a side rear-view of the vehicle 2. The mirror plate is mounted to an adjustment means, comprising a series of actuators, contained in the mirror housing 12 for adjusting the orientation of the mirror plate with respect to the mirror housing 12. Such adjustment means are well-known, and so will not be described in further detail.

The mounting arm 10 comprises a first portion 16, which is attached at one end to the door 14 of the vehicle 2, and a second portion 18. A distal end of the first portion 16 is attached to the second portion 18, which, in turn, is attached to the mirror housing 12 of the mirror assembly 8. At least one portion of the first and second portions 16, 18 comprises a cross-sectional aerofoil element as will be explained in more detail below.

The first portion 16 is configured to extend from the door 14 in a direction which is generally parallel with the lateral axis of the vehicle 2. The second portion 18 is configured to extend from the first portion 16 in a direction that is generally parallel with the vertical axis of the vehicle 2, when the first portion 16 is connected to the door 14.

The second portion 18 is arranged to connect, at its upper end, to the underside of the mirror housing 12. Hence, when the mirror assembly 8 is mounted to the vehicle 2, the first and second portions 16, 18 are arranged such that they define, respectively, lateral and vertical portions of the mounting arm 10.

The first and second portions 16, 18 are formed integrally with one another so as to define a unitary component of the mirror assembly 8. Alternatively, the first and second portions 16, 18 may be formed separately and then joined together to form a unified component.

With reference to FIG. 2, the arrangement of the mirror housing 12 and the mounting arm 10 means that, together, they define a channel 30 with the exterior surface of the door 14. The channel 30 is arranged to accommodate a strong air flow structure that develops around the base of windscreen pillar 4 and extends lengthwise along the side of the vehicle 2, increasing the aerodynamic efficiency of the mirror assembly 8 when compared to known rear view mirror assemblies, as will be explained in more detail below.

In cross-section, the channel 30 generally comprises a first section 32, defined by the inboard side wall 24 of the mirror housing 12 and the adjacent, opposing, exterior surface of the door 14. The channel 30 narrows to a second section 34 which is defined by the bottom wall 22, or underside, of the mirror housing 12 and an opposing upper surface of the first portion 16 of the mounting arm 10.

The second section 34 terminates, at its outboard side, by the second portion 18 of the mounting arm 10 and, at its inboard side, by the exterior surface of the door 14, and comprises an approximately constant cross-section along its width. The height of the second section 34 is determined by the height of the second portion 18 of the mounting arm 10 and its length, as defined by a longitudinal direction of the vehicle 2, is determined by the length of the first portion 16 of the mounting arm 10.

As mentioned above, the mirror assembly 8 is arranged at a distance from the windscreen pillar 4 and the exterior surface of the door 14 so that the air flow structure, extending from the base of the of windscreen pillar 4, can flow through the channel 30 defined between the mirror assembly 8 and the vehicle 2. The air flow structure is a turbulent air flow structure extending lengthwise, from a region around the base of windscreen pillar 4, along the side of the vehicle 2, and is formed from a convergence of air flowing along the bonnet of the vehicle 2 towards the windscreen 6 and air flowing laterally across windscreen 6 in the direction of the windscreen pillar 4. Due to irregular pressure fluctuations generated by its turbulent composition, the air flow structure is a primary source of noise and vibration in the vicinity of mirror assembly 8.

A conventional mirror support structure would present an obstacle to the airflow structure, in the form of a bluff body, causing it to deflect around the mirror assembly 8 in an uncontrolled manner, adding to the noise and vibration effects in the area surrounding the mirror assembly 8.

By contrast, the mounting arm 10 of the mirror assembly 8 according to the present invention is displaced to a position which is substantially below and outboard of the airflow structure. As is illustrated by the flow lines F in FIGs. 1 to 3, the airflow structure extends from the windscreen pillar 4, through the first and second sections 32, 34 of the channel 30. The arrangement of mounting arm 10 allows the airflow to pass by the mirror assembly 8 with minimal interaction, increasing the aerodynamic performance of vehicle 2 and reducing the noise and vibration effects when compared with a mirror assembly having a conventional mirror support.

The positioning and arrangement of the mounting arm 10 will now be described with reference to FIGs. 2 and 3. The first portion 16 of the mounting arm 10 extends at least approximately horizontally, and in a direction which is substantially transverse to the longitudinal axis of the vehicle 2.

The mounting arm 10 is secured to the door 14 at a distance, in the height direction, below a door sill 36. The door sill 36 represents the intersection between the exterior door panel 38 and a side window 40 of the door 14. Put another way, the mirror assembly 8 is connected to the exterior door panel 38 at a position lower than an intersection between the windscreen pillar 4 and front wing of the vehicle 2.

The height of the connection point and the height of the second portion 18 of the mounting arm 10 are dimensioned such that the lower edge of the mirror housing 12 is only slightly below the height of the door sill 36. The connection point of the mounting arm 10 is also arranged to the rear of the intersection between the windscreen pillar 4 and the door 14, as shown in FIG. 1.

The width of the first portion 16 of the mounting arm 10, as defined by the lateral axis of the vehicle 2, is dimensioned such that the mounting arm 10 connects to the mirror housing 12 at a location which is close to the outboard side wall 26 of the mirror housing 12. This arrangement of the mounting arm 10 maximises the width of the second section 34 of the channel 30, thereby increasing the flow capacity the channel 30 defined between the vehicle body and the mirror assembly 8.

The width of the first portion 16 of the mounting arm 10 is approximately 100 mm. The height of the second portion 18 is similar to the height of the mirror housing 12.

Increasing the width of the first portion 16 and/or the height of the second portion 18 of the mounting arm 10 increases the area of the opening of the channel 30, thereby further reducing the interaction between flow structure and the mirror assembly 8.

The thickness (or height) of the first portion 16 of the mounting arm 10, as defined by the vertical axis of the vehicle 2, is substantially less than the height of the mirror housing 12. The thickness of the second portion 18, as measured in the lateral axis of the vehicle 2, is substantially similar to the thickness of the first portion 16. The greatest thickness of the mounting arm 10 is approximately one tenth of the height of the mirror housing 12.

The inboard sidewall 24 of the mirror housing 12 is substantially aligned with a vertical axis of the vehicle 2. In embodiments, the inboard sidewall 24 may be configured such that it follows the contour lines of the outwardly facing surface of the door 14.

As illustrated in FIG. 2, the contour of the vehicle 2 deviates in an inboard direction in the region just below the intersection between the exterior door panel 38 and the front left windscreen pillar 4. This deviation contributes to the formation of the channel 30 between the door 14 and the mirror housing 12. The shape of the exterior door panel 38 means that the width of the first portion 16 of the mounting arm 10 can be substantially the same as the width of the mirror housing 12 whilst still providing a channel for air to flow between the mirror housing 12 and the vehicle 2.

In alternative embodiments, the exterior door panel 38 may be arranged with a substantially vertical contour line. It will be appreciated by the skilled person that in such circumstances, either the width of the mirror housing 12 must be decreased and/ or the width of the first portion 16 of the mounting arm 10 must be increased in order to provide a channel that is sufficiently large enough to allow the oncoming air to flow between the mirror assembly 8 and the vehicle 2 in the desired manner.

As described earlier, the length of the first and second portions 16, 18 are defined with respect to the longitudinal axis of the vehicle 2, when the mirror assembly 8 is mounted to the door 14. FIG. 4 shows a plan view of the mounting arm 10 taken through a cross-section of the second portion 18 along the dotted line A-A, as shown in FIG. 2, The first portion 16 is dimensioned such that its width, as defined by the lateral direction of the vehicle 2, is substantially similar to its length.

The length of the second portion 18 of the mounting arm 10, at the region where it connects with the first portion 16, is arranged to be substantially similar to the length of the first portion 16. The length of the second portion 18 then tapers towards its connection with the mirror housing 12, as illustrated in FIG. 1.

The mounting arm 10 is dimensioned so as to provide structural stability to the mirror assembly 8, such that it can withstand the forces that are exerted upon it by the oncoming air flow and the irregular pressure fluctuations of the turbulent airflow structure, and also by the cantilevered mass of the mirror housing 12.

In particular, the mounting arm 10 is configured so that its thickness can be minimised whilst maintaining the structural properties that are required to support the weight of the mirror assembly 8. The length of the first portion 16 is such that it enables a reduction in its thickness, which reduces the forward facing surface of the mounting arm 10 and decreases the overall drag caused by the mirror assembly 8.

In this way, the forward facing surfaces of the mounting arm 10 that are presented to the oncoming airflow when the vehicle is in motion can be reduced, thereby increasing the aerodynamic efficiency of the mirror assembly 8.

The leading and trailing edges 54, 56 of the first portion 16 are arranged substantially in parallel with each other. The first portion 16, where it connects with the door panel 38 is radiused so as to accommodate the curvature of the door panel 38, whilst ensuring a continuous joint between the door 14 and the mounting arm 10.

Turning now to FIG. 3, which illustrates a plan view of the mirror assembly 8 mounted to the door 14, it is shown how the mirror housing 12 extends inwardly toward the vehicle body with a slight inclination in a forward direction from its point of attachment with the mounting arm 10.

The inboard side wall 24 of the mirror housing 12 is oriented so that its distance from the adjacent portion of the door 14 decreases in the longitudinal direction of the vehicle (i.e. from the leading edge to the trailing edge of the mirror housing 12). This leads to a general narrowing of the first section 32 of the air channel 30 in a longitudinal direction of the vehicle 2.

The height of the second section 34 of the air channel 30, as measured in a vertical direction of the vehicle 2, decreases in a longitudinal direction relative to the vehicle 2 (i.e. in the direction of the airflow as it travels through the channel 30 from the leading edge of the mirror housing 12 to its trailing edge), as illustrated in FIG. 1. This is due to the increase in the height of the mirror housing 12, in a longitudinal direction of the vehicle, resulting from the curvature of the mirror housing's exterior shell. Put another way, the curved shape of the underside of the mirror housing 12 gives rise to a reduction in the height of the air channel 34 in a longitudinal direction, as measured from a leading to trailing edge of the mirror housing 12.

A rearward portion 42 of the inboard side wall 24 is substantially parallel with the adjacent contour line of the exterior door panel 38. The inboard side wall 24 deviates from its alignment with the vehicle contour line as it moves toward a forward portion 42 of the mirror housing 12, due to the curved shape of the mirror housing's exterior shell.

The first portion 16 of the mounting arm 10 is arranged so that it extends in a direction that is substantially perpendicular to the plane of the exterior door panel 38. The leading and trailing edges of the mirror housing 12 are substantially parallel with each other, and are each arranged at an angle with respect to the lateral axis of the vehicle 2.

The mirror housing 12 is therefore angled in a forward direction from its point of connection with the mounting arm 10 such that an inboard portion of the mirror housing 12 protrudes forward of the first portion 16 of the mounting arm 10, as illustrated in FIG. 3.

FIG. 5 illustrates a cross-section through the first portion 16 of the mounting arm 10 corresponding to the dotted line B-B, as shown in FIG. 4. The profile of the cross-section comprises an aerofoil element 50. The aerofoil element 50 reduces the pressure of the oncoming air passing over the first portion 16 of the mounting arm 10, thereby creating an area of low pressure within the second section 34 of the channel 30, which pulls the airflow away from the mirror housing 12, increasing the aerodynamic efficiency of the mirror assembly 8.

The aerofoil element 50 has an arc-shaped camber line 52 and is configured to have a positive angle of attack with respect to the oncoming airflow when the mounting arm 10 is connected to the door 14. The leading edge 54 of the first portion 16 of the mounting arm 10 is therefore higher than its trailing edge 56.

The positive angle of attack is represented by the chord line C of the aerofoil element 50, which is angled in an upward direction relative to the horizontal axis of the vehicle 2. The resulting configuration of the aerofoil element 50 means that when the vehicle 2 is travelling along a straight and level surface, then at least a part of the first portion 16 of the mounting arm 10 is arranged at an inclined angle with respect to the underlying road surface.

The angle of attack of the cross-sectional aerofoil element 50 of the first portion 16 of the mounting arm 10 is +5 degrees with respect to the horizontal axis of the vehicle 2. Alternatively, the angle of attack may be any angle between +5 degrees and +10 degrees.

The aerofoil element 50 is configured such that at least part of the underside of the first portion 16 of the mounting arm 10 comprises a concave profile 58. The concave part of the first portion 16 is arranged to face in a downward direction, towards the underlying road surface, when the mirror assembly 8 is connected to the vehicle 2. The concavity of the concave profile 58 is substantially equivalent to the upper camber of the aerofoil element 50 of the first portion 16.

According to particular example of the mirror assembly, the lower surface of the mirror housing 12 may be arranged to substantially match the camber of the opposing upper surface of the first portion 16 of the mounting arm 10. Accordingly, the height of at least a portion of the second section 34 of the air channel 30 is configured to be substantially uniform when measured in a longitudinal direction of the vehicle 2.

In this embodiment, at least a section of the second portion 18 of the mounting arm 10 is also configured with an aerofoil element. The aerofoil element of the second portion 18 is arranged such that at least part of the second portion 18 has an arc-shaped camber line on its inboard surface, i.e. the inwardly facing surface of the mounting arm 10.

At least part of the outwardly facing surface of the second portion 18 comprises a concave profile. The concave surface of the second portion 18 is arranged to face in a generally outward direction with respect to the door 14 when the mirror assembly 8 is connected to the vehicle 2.

The concavity of the concave profile is substantially equivalent to the inner camber of the cross-sectional aerofoil element of the second portion 18. Accordingly, the aerofoil element of the second portion 18 is configured such that its leading edge is arranged inboard of its trailing edge, when the mounting arm 10 is attached to the door 14. Put another way, the trailing edge of the second portion 18 of the mounting arm 10 is further outboard than its leading edge.

The angle of attack is defined relative to the chord line of the aerofoil element of the second potion 18, which is angled inwardly toward the door panel 14, when the mirror assembly is connected to the vehicle 2. The angle of attack of the aerofoil element of the second portion 18 can also be defined relative to the longitudinal axis of the vehicle 2.

For example, a 0 degree angle of attack corresponds to the chord line of the aerofoil element of the second portion 18 being substantially parallel with the longitudinal axis of the vehicle 2. A positive angle of attack (i.e. an angle greater than 0 degrees) corresponds to the leading edge of the second portion 18 being angled toward the door 14, whereas a negative angle of attack would represent an arrangement of the second portion 18 in which its leading edge is angled away from the vehicle 2.

According to the present invention, the cross-sectional aerofoil element of the second portion 18 is configured to have a positive angle of attack when the first portion 16 is connected to the door panel. In particular, the cross-sectional aerofoil element of second portion 18 is arranged with a positive angle of attack of +5 degrees. Alternatively, the angle of attack may be +10 degrees. The angle of attack may further be between +5 and +10 degrees from the longitudinal angle of the vehicle 2.

When the vehicle is traveling forward, the air flowing through the exterior rear view mirror assembly 8 is steered through the channel 30 which is formed between the mirror assembly 8, the mounting arm 10 and the door 14. The aerofoil elements of the first and second portions 16, 18 cause a reduction in the air pressure in the air-channel 30 which sucks the airflow through the air channel 30 and away from the mirror housing 12.

In particular, the aerofoil profile of the first portion 16 of the mounting arm 10 causes a portion of the air flowing within the second section 34 of the channel 30 to be directed in down and away from the mirror housing 12. Simultaneously, the air flowing near to the outboard end of the second section 34 is directed away from the door 14 by the aerofoil profile of the second portion 18 of the mounting arm 10.

The arrangement of the mounting arm 10 displaces the first and second portions 16, 18 away from areas of the vehicle in which strong flow structures develop, thereby preventing any adverse interactions therewith. The aerofoil elements of mounting arm 10 cause a region of low pressure to form which preferentially diverts airflow into the second section 34 of the air channel 30.

In addition, the narrowing of the channel 30 between the first and second sections 32, 34 (i.e. between the most inboard portion of the mirror housing 12 and the opposing outer surface of the door panel 38) causes a Venturi effect in this connecting region of the air channel 30. The resulting reduction in air pressure further accelerates the airflow through the channel 30.

Each of these effects caused by the configuration of the mounting arm 10 leads to the oncoming airflow being outwashed from the mirror assembly 8, resulting in an increase in the aerodynamic efficiency of the vehicle 2.

The aerofoil elements of the mounting arm 10 help to reduce the aerodynamic drag of the mirror assembly 8. In addition, the aerofoil elements smooth out the flow of air through the air channel 30, which reduces the noise vibration harshness (NVH) experienced by the occupants of the vehicle 2.

It will be appreciated that a mirror assembly may comprise numerous modifications and alterations to the above described embodiments without departing from the scope of the present invention. For example, the length, width and thickness, the angle of inclination, the height and the profile shape of the mirror housing and mounting arm each interact with the components that are located in the vicinity of the exterior rear view mirror assembly, such as the windscreen, front windscreen pillar, and the quarter window. The dimensions described above regarding the exemplary embodiment have proved to be particularly advantageous in a given vehicle. The desired effect, however, can also be achieved if deviations are made to the relevant components within a range of +/-20% of the stated values.

The specific embodiment is described herein as comprising a first and second portion 16, 18 with each portion comprising a cross-sectional aerofoil element. However, it will be appreciated that one or the other of the first and second portions 16, 18 may be arranged such that they do not comprise a cross-sectional aerofoil element without departing from the present invention. In embodiments, only one of the first and second portions 16, 18 of the mounting arm 10 may be configured with a cross-sectional aerofoil element.

In embodiments, the mounting arm may be arranged to allow the mirror housing to be adjusted relative to the body of the vehicle. In this way, the mounting arm enables the mirror assembly to be arranged in a deployed position when the vehicle is in use, and a stowed position when the vehicle is parked.

It will be appreciated that, whilst the present invention has been described with reference to FIGs. 1 to 5 showing a left side exterior rear-view mirror, the same inventive concept could be applied, equally, to a mirror assembly arranged to be provided on the right side of a vehicle. The corresponding exterior rear-view mirror assembly for the right side of the vehicle is arranged in a mirrored configuration compared to the left sided mirror assembly which is shown in FIGs. 1 to 5. Otherwise, the right sided mirror assembly comprises substantially the same components as the left side mirror assembly as described herein.

Claims

CLAIMS1. An exterior rear view mirror assembly for a vehicle, the mirror assembly comprising: a mirror housing comprising a forward facing aerodynamically shaped exterior shell terminating in a rearward trailing edge; a rearwardly facing reflecting surface mounted in the mirror housing; and, a mounting arm for connecting the mirror housing to the vehicle, the mounting arm comprising a first portion connectable to a door panel of the vehicle and configured to extend generally laterally therefrom and a second portion configured to extend generally vertically from the first portion when the first portion is connected to the door panel and connect to the underside of the mirror housing, wherein at least one portion of the first and second portions comprises a cross-sectional aerofoil element.
2. An exterior rear view mirror assembly according to claim 1, wherein the other portion of the first and second portions comprises a cross-sectional aerofoil element.
3. An exterior rear view mirror assembly according to claim 1 or 2, wherein the cross-sectional aerofoil element of the at least one portion of the first and second portions is configured to have a positive angle of attack when the first portion is connected to the door panel.
4. An exterior rear view mirror assembly according to claim 2 or 3, wherein the cross-sectional aerofoil element of the other portion of the first and second portions is configured to have a positive angle of attack when the first portion is connected to the door panel.
5. An exterior rear view mirror assembly according to claim 3 or 4, wherein the angle of attack of the cross-sectional aerofoil element of the first portion and/ or the second portion is between +5 and +10 degrees.
6. An exterior rear view mirror assembly according to any preceding claim, wherein at least part of the underside of the mirror housing comprises a concave profile.
7. An exterior rear view mirror assembly according to claim 6, wherein the concavity of the concave profile is substantially equivalent to the upper camber of the cross-sectional aerofoil element of the first portion such that the height of at least a section of the channel defined between the underside of the mirror housing and the upper surface of the first portion is uniform.
8. An exterior rear view mirror assembly according to claim 5 or claim 6, wherein the concavity of the concave profile is configured such that the height of at least a section of the channel defined between the underside of the mirror housing and the upper surface of the first portion decreases in a longitudinal direction from a leading to a trailing edge of the mirror housing.
9. A vehicle comprising an exterior rear view mirror assembly according to any preceding claim.
10. A vehicle according to claim 9, wherein the first portion of the exterior rear view mirror assembly is connected to the door panel at a position lower than an intersection between the windscreen pillar and the front wing of the vehicle.
11. A vehicle according to claim 10, wherein a contour of the vehicle, in a region below the intersection between the windscreen pillar and the front wing, is configured to deviate in an inboard direction to form at least a section of the channel defined between the mirror housing and the vehicle.