JP2007076461A - Door mirror device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a door mirror device for reducing wind noise by preventing a flow passing through an air flow passage between a mirror base part and an inside part of a mirror housing from hitting a side window. <P>SOLUTION: The door mirror device for an automobile is provided with the mirror base part 4 provided in a triangle zone at a front end of the side window on a belt line front end part of a side door, a stay part 5 protruding outward in a vehicle width direction from the mirror base part 4, and the mirror housing 7 for housing a mirror 16 mounted on the stay part 5. The inside part 7A of the mirror housing 7 facing the mirror base part 4 is formed in an approximately planar shape. On an upper part of the stay part 5, the air flow passage 13 is formed between the mirror base part 4 and the inside part 7A. The air flow passage 13 is formed in an inverted trapezoidal shape with an upper part widened between the mirror base part 4 and the inside part 7A of the mirror housing 7 in vehicle front view. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a mirror base portion provided in a triangular region at the front end of a side window at a belt line front end portion of a side door of an automobile, a stay portion protruding outward in the vehicle width direction from the mirror base portion, and a stay portion More particularly, the present invention relates to a door mirror device that improves aerodynamic performance.

  In general, improvement of the three performances of the door mirror (wind noise, air drag coefficient Cd value, raindrop adhesion) is required. In particular, the reduction of wind noise and Cd value is important for improving the quietness and fuel efficiency when driving at high speed. In recent years, this countermeasure has attracted attention.

  There are various possibilities for the shape of the door mirror (mirror housing), and it is not clear what changes will make it better. Therefore, under the present circumstances, the shape of the so-called feature obtained from past experience is subjected to an external design for each vehicle type, and a wind tunnel experiment is performed, and the result is suitable.

  On the other hand, there is a demand to expand the mirror area in the vertical direction in accordance with European regulations and widen the rear view by the mirror. In this case, wind noise, Cd There is concern that the value will deteriorate.

  Therefore, the present applicant uses both wind tunnel experiments and fluid numerical simulations (hereinafter simply referred to as CFD) for 18 types of door mirror models in which the characteristic dimensions of the door mirror housing are variously changed. An enormous man-hour effort was made to find the best shape that achieves both high wind noise and Cd values.

  The following knowledge was acquired by this approach. That is, the turbulent flow passing through the gap (air flow path) between the mirror housing and the side window acts to strike the side window glass, causing periodic pressure fluctuations on the glass surface, Generate wind noise. This was clarified by an experiment in which about 25 small-diameter through holes were drilled in the window and a pressure sensor was inserted from the inside of the window to measure the pressure distribution on the outer surface of the window.

  In addition, the turbulent flow passing through the air flow path disturbs the flow on the side of the vehicle behind the front pillar, resulting in an increase in the vortex behind the vehicle and adversely affecting the Cd value. Giving was clarified by grasping CFD. Therefore, it is desirable that the shape of the air flow path does not disturb the subsequent flow as much as possible.

  By the way, in patent document 1, the vehicle side surface of the door mirror is formed into a planar shape, the degree of change in the vehicle width direction of the air flow path is reduced from the front to the rear of the vehicle, and the flow passes through the air flow path. A structure that does not cause disturbance is disclosed. Patent Document 2 discloses a structure in which a vehicle-side surface of a door mirror is formed in a non-planar substantially cylindrical shape, and an air flow path is widened in a plan view on the rear side with respect to the narrowest portion thereof. .

However, in these Patent Documents 1 and 2, it is difficult to reach the best shape of the door mirror because sufficient and detailed analysis has not been made.
The present applicant has obtained the following knowledge through experiments and CFD of the above 18 types of door mirror models. In other words, the air flow path (gap part) needs to have a shape that does not cause as much disturbance as possible, but if the amount of air (flow rate) flowing backward through the flow path is excessive, how It became clear that even if the turbulence is small, the wind noise and the cost for improving the Cd value are small. That is, the shape of the air flow path requires that air is not so much introduced from the front of the vehicle and that the turbulence of the flow passing therethrough is small.

JP 2000-177487 A JP-A-8-310302

  Therefore, the present invention has an inverted trapezoidal shape when the air flow path between the mirror base part and the mirror housing inner part is viewed from the front based on the above 18 kinds of door mirror model experiments and knowledge obtained by CFD, In addition, the flow passing through the air flow path is formed by forming the cross section of the flow path without a narrow portion like the reverse acute angle triangular shape in a straight line continuously in the front-rear direction, for example, by making the inner portion substantially flat. It is an object of the present invention to provide a door mirror device that can prevent the air from being deflected and hitting the side window, thereby suppressing the turbulence behind the air flow path, thereby reducing the wind noise and the Cd value.

  A door mirror device according to the present invention includes a mirror base portion provided in a triangular region at a front end of a side window at a front end portion of a belt line of a side door, a stay portion protruding outward in the vehicle width direction from the mirror base portion, and the stay portion. And a mirror housing that contains a mirror and is provided with a mirror housing, wherein an inner portion of the mirror housing facing the mirror base portion is formed in a substantially flat shape, and the mirror base is disposed above the stay portion. An air flow path is formed between the inner part and the inner part, and the air flow path is formed in an inverted trapezoidal shape in which the upper part is wide between the mirror base part and the inner part of the mirror housing in a front view of the vehicle. It is.

  According to the above configuration, the air flow path described above is formed in an inverted trapezoidal shape when viewed from the front, that is, an upwardly widened shape having a bottom of a predetermined length, and the inner portion facing the mirror base portion of the mirror housing is formed. Since it has a substantially planar shape, a cross-section of the flow path without a narrow portion such as an inverted acute triangle is formed linearly and continuously in the front-rear direction, and the flow passing through the air flow path is deflected to form a side window. Can be prevented, and the turbulence behind the air flow path can be suppressed. As a result, it is possible to reduce the wind noise and the Cd value.

In one embodiment of the present invention, the inner portion of the mirror housing is set to spread upward at an angle of 5 to 15 degrees with respect to the vehicle vertical direction.
According to the said structure, a wind noise can be reduced most by the angle setting of 5-15 degrees. In other words, when the angle exceeds 15 degrees, the turbulence generated in the air flow path decreases, and the wind noise and Cd value tend to decrease, but the flow rate of air passing through the air flow path increases, and the wind noise and Cd value gets worse. Furthermore, the cross section in the vehicle width direction of the air flow path is wider at the top and narrower toward the bottom, so the lower flow velocity is greater than the upper flow velocity, and a velocity gradient is formed in the vertical direction of the air flow path. A vortex resulting from this velocity gradient is generated. Wind noise and Cd value are also deteriorated due to this vortex. On the other hand, when the angle is less than 5 degrees, the cross section in the vehicle width direction of the air flow path becomes a vertically long rectangular shape, and the mirror base portion and the inner side of the mirror housing are close to each other over the air flow path. As a result, the flow on the front pillar side and the flow on the mirror housing side easily interfere with each other, and a vortex is generated to deteriorate the wind noise and the Cd value. Therefore, the angle range is set.

In one embodiment of the present invention, the depth of the air flow path is set to be larger than the vertical width of the stay portion when the vehicle is viewed from the front.
According to the above configuration, an increase in the Cd value due to the vertical width of the stay portion can be prevented.

In one embodiment of the present invention, at least the latter half of the air flow path is formed so as to be widened rearward in a plan view.
According to the above configuration, the plan view configuration of the air flow path is configured so as to be widened rearward together with the above-described front view structure of the mirror housing, so that the traveling wind passing through the air flow path is substantially the same as that of the mirror housing. Flows in parallel from the front of the vehicle to the rear of the vehicle along the flat inner side, without causing a flow toward the side window, and abrupt speed changes are eliminated. And vortex interference caused by the mirror housing can be eliminated, and wind noise and air resistance caused by the door mirror can be greatly reduced.

In one embodiment of the present invention, the front side portion and the inner side portion of the mirror housing form an acute ridge line portion in a horizontal section.
According to the above configuration, since the acute ridge line portion is formed, the traveling wind that collides with the front side portion of the mirror housing is formed between the mirror base portion and the inner side portion of the mirror housing (as compared to the case where the obtuse angle is formed). The air flow is less likely to be introduced into the air flow path, and the amount of air passing through the gap flow is reduced, so that the vortex resulting from the mirror housing is relatively reduced with respect to the gap flow.

In one embodiment of the present invention, the vertical width of the stay portion is set to a predetermined width such that the upper end of the stay portion is positioned below the height center line of the mirror housing.
According to the above configuration, it is possible to achieve both reduction in pressure fluctuation on the side window surface and support rigidity of the mirror housing. That is, when the vertical width of the stay portion is too small and the depth of the air flow path is excessive, the flow rate of air passing through the air flow path increases, and the pressure fluctuation on the side window surface increases, The support rigidity of the mirror housing deteriorates. On the other hand, when the vertical width of the stay part is excessive and the depth of the air flow path is excessively small, wake vortex generation due to the vertical width of the stay part is intense and air resistance increases. It is set as described above.

  According to the present invention, the air flow path between the mirror base portion and the inner side of the mirror housing is an inverted trapezoidal shape when viewed from the front, that is, an upwardly widened shape having a bottom of a predetermined length, and the mirror housing Since the inner part facing the mirror base part is substantially planar, a channel cross section without a narrow part such as an inverted acute triangle is formed linearly and continuously in the front-rear direction. It is possible to prevent the passing flow from deflecting and hitting the side window, and to suppress the flow behind the air flow path, thereby reducing the wind noise and the Cd value.

  The mirror base part provided in the triangular area of the front end of the side window at the front end of the belt line of the side door, and the mirror for the purpose of preventing the flow passing through the air flow path from hitting the side window and reducing wind noise In a door mirror device for an automobile comprising a stay portion that protrudes outward in the vehicle width direction from a base portion and a mirror housing that is attached to the stay portion and accommodates a mirror, the inner portion of the mirror housing that faces the mirror base portion is substantially The air flow path is formed between the mirror base part and the inner part above the stay part, and the air flow path is formed between the mirror base part and the inner part of the mirror housing in the vehicle front view. This is realized by a configuration in which the upper part is formed in an inverted trapezoidal shape that is wide.

An embodiment of the present invention will be described in detail with reference to the drawings.
The drawings show a door mirror device. In FIGS. 1 to 3, this door mirror device is located in a triangular area at the front end of the side window 3 at the front end of the belt line 2 (belt line, agreed with the waist line) of the side door 1 (front door). A mirror base portion 4 provided, a stay portion 5 projecting outward in the vehicle width direction from the mirror base portion 4, and a mirror 6 (see FIG. 4) attached to the stay portion 5 for rearward viewing are accommodated. And a pair of door mirror devices are configured symmetrically. The above-described mirror base portion 4 is a flat triangular base, and this mirror base portion 4 constitutes the vehicle body side of an air passage 13 (gap portion passage) described later.
1 to 3, 8 is a bonnet, 9 is a front window glass, 10 is a roof portion, and 11 and 11 are left and right front pillars.

  4 is a rear view of the right-side door mirror device (drawing from the direction of arrow Y in FIG. 5), and FIG. 5 is a view taken along the line AA in FIG. The inner portion 7A (facing) is formed in a substantially planar shape, and the rear portion of the substantially planar inner portion 7A from the pivot center 12 as the door mirror rotation center (door mirror storage center) is shown in plan view in FIG. As shown in FIGS. 4 and 5, the rear side of the vehicle extends in the plan view by the mirror base portion 4 and the inner portion 7A above the stay portion 5, as shown in FIGS. At least the latter half of the inner portion 7A forms an air flow path 13 (so-called gap) that becomes wider at a predetermined widening angle θ1 toward the rear of the vehicle.

Here, the air flow path 13 between at least the rear half part of the inner part 7A (the part constituting the door mirror side of the air flow path 13) in the mirror housing 7 and the mirror base part 4 is shown in FIG. The above-mentioned widening angle θ1 with respect to the direction line L1 is set to 4 to 6 degrees, preferably 5 degrees, and the flow toward the side window 3 is suppressed by the rearwardly spreading shape of the inner portion 7A, so that the front pillar 11 and the mirror housing 7 are prevented from interfering with each other.
Further, the inner portion 7A of the mirror housing 7 and the front side portion 7B of the mirror housing 7 where the traveling wind directly collides constitute a ridge line portion 14 having an acute angle θ2 in a horizontal section (see FIG. 5). .

  That is, the angle θ2 formed by the tangent line L2 on the front side of the inner part 7A and the tangent line L3 of the front side part 7B is configured to be 90 degrees or less. In this embodiment, the acute angle θ2 is set to 75 to 80 degrees, and this configuration makes it difficult for the traveling wind that collides with the front side portion 7B to be introduced into the air flow path 13 and reduces the amount of air passing through the gap flow. The vortex resulting from the mirror housing 7 is made relatively small with respect to the gap flow.

  The ridge line portion 14 formed by the inner portion 7A and the front side portion 7B of the mirror housing 7 is formed with a radius of curvature R1 = 10 mm or less in a horizontal section (see FIG. 5). If the radius of curvature exceeds 10 mm, the vortex of the gap flow generated due to the ridge line portion is observed.

  Further, the above-described front side portion 7B is formed in an arc shape in plan view (see FIG. 5), and the front side portion 7B is formed to recede toward the vehicle outer side in order to reduce air resistance.

  More specifically, the front side portion 7B of the above-described mirror housing 7 is configured to recede to the vehicle outer side at an angle θ3 of 15 degrees or more from the vehicle width direction line L4 in the horizontal section shown in FIG. 5 when the door mirror is used. In this embodiment, the aforementioned angle θ3 is set to 22 ° ± 1.5 °.

  In addition, in order to satisfy the design requirements, the front half of the inner portion 7A of the mirror housing 7 described above is wide at 20 degrees or less toward the front of the vehicle in a plan view (see FIG. 5) with respect to the vehicle longitudinal direction line L1. An opening angle portion θ4 is formed. In this embodiment, [theta] 4 is set to around 10 [deg.] To improve the appearance.

  6 is a view as seen from the direction of the arrow X in FIG. 5 (drawing as seen from an obliquely rearward direction of the vehicle perpendicular to the mirror surface), FIG. 7 is a view taken along the line BB in FIG. 9 is a view taken along the line D-D in FIG. 6, FIG. 10 is a view taken along the line E-E in FIG. 6, and FIG. 11 is a view taken along the line G-G in FIG. 8 to 11, the front side portion 7B of the mirror housing 7 is formed in a substantially semicircular shape in a side view so as to reduce air resistance, and is viewed in the center of the door mirror in the longitudinal direction along the line EE. As shown in FIG. 10, the lower piece portion of the front side portion 7B is configured such that the front is inclined upward at a predetermined angle θ5 with respect to the vehicle longitudinal direction line L5, and the upper piece portion of the front side portion 7B. Is configured such that the front is inclined downward at a predetermined angle θ6 with respect to the vehicle front-rear direction line L6. In this embodiment, the angle θ5 is set to about 2 degrees, and the angle θ6 is set to 10 to 15 degrees. 8, 10, and 11 indicate the shape of the mirror housing 7 in FIG. 9 as viewed from the direction of the arrows D-D in FIG. 6.

  On the other hand, FIG. 4 shows a drawing (rear view) seen from the direction of arrow Y in FIG. 5, and FIG. 6 shows a drawing seen from the direction of arrow X in FIG. In FIG. 4, the upper part is formed in an inverted trapezoidal shape that is wide at a predetermined widening angle θ 7 between the mirror base part 4 and the inner part 7 A of the mirror housing 7.

  Here, the upper part forming the air flow path 13 in the inner part 7A of the mirror housing 7 is set to spread upward at an angle θ7 of 5 to 15 degrees, preferably 5 degrees with respect to the vehicle vertical direction line L7. The inner portion 7A is configured to prevent the flow passing through the air flow path 13 from hitting the surface of the side window 3 and preventing the rear flow from being disturbed. Yes. For example, when the angle θ7 exceeds 15 degrees, the upper air flow velocity in the air flow path 13 is decreased, the lower air flow velocity in the air flow path 13 is increased, and the vortex is caused by the velocity gradient. This causes aerodynamic performance and wind noise to deteriorate.

Further, as shown in FIG. 4, the depth DE of the air flow path 13 described above is set to be larger than the vertical width w of the stay portion 5 in front view of the vehicle. The area where the stay portion 5 hits the traveling wind is reduced to reduce the aerodynamic resistance.
This depth DE is preferably about 110 mm. Further, the vertical width w of the stay portion 5 is set to a predetermined width at which the upper end 5a of the stay portion 5 is positioned below the height center line L8 (so-called horizontal line) of the mirror housing 7. In addition, it is desirable that the protruding length LE of the stay base 5 from the mirror base portion 4 outward in the vehicle width direction is about 35 mm. That is, if the vehicle width direction length of the lower part of the air flow path 13 is set to about 35 mm, the flow entering the air flow path 13 is not accelerated and smoothly passes through the air flow path 13, so that air performance and wind noise are improved. . However, it is not limited to LE = 35 mm.

12 is a plan view of the right side door mirror device, and FIGS. 13 to 20 are respective arrow views taken along lines H1-H1 to H8-H8 in FIG. 12, and the air flow path 13 is shown in FIG. The outer contour line 7C of the mirror housing 7 is configured to gradually increase from the vehicle front side shown in FIG. 13 to the vehicle rear side shown in FIG. Here, an imaginary line β shown in FIGS. 13 to 19 shows an outer shape of the mirror housing 7 of FIG. 20 as a view taken along line H8-H8 of FIG.
In the figure, arrow F indicates the front of the vehicle, arrow OUT indicates the outside of the vehicle, and arrow IN indicates the inside of the vehicle.

  Next, using the door mirror m1 of the example product shown in FIG. 21 (a) and the door mirror m2 of the comparative example product shown in FIG. 21 (b), changes in speed and speed (intensity of turbulence) in the mainstream direction by CFD. The results of analyzing the vorticity distribution (CFD analysis) are shown (see FIGS. 22 to 27).

  However, as the door mirror m1 of the example product, as shown in FIG. 21 (a), the entire inner portion 7A of the mirror housing 7 is wide toward the vehicle rear at an angle θ1 = 5 ° with respect to the vehicle front-rear direction line L1. And a door mirror model having a ridge line portion 14 with R1 = 0. Further, as a door mirror m2 of the comparative example, as shown in FIG. 21 (b), the rear portion of the inner portion 7A of the mirror housing 7 is at the rear of the vehicle at an angle θ1 = 10.5 ° with respect to the vehicle front-rear direction line L1. The front portion of the inner portion 7A of the mirror housing 7 becomes wider toward the front of the vehicle at an angle θ4 = 25 to 26 degrees with respect to the vehicle front-rear direction line L1, and the curvature radius R2 >> 10 mm of the ridge line portion 14 A set door mirror model was used.

  FIG. 22 shows the analysis result of the velocity in the mainstream direction in the horizontal plane including the mirror housing height center line L8 of the door mirror m1 of the example product, and FIG. 23 shows the height of the mirror housing of the door mirror m2 of the comparative example. The analysis result of the velocity in the mainstream direction in the horizontal plane including the center line is shown. However, in FIG. 22 and FIG. 23, for convenience of illustration, it is shown that as the hatching becomes denser, the speed increases, and the speed becomes relatively maximum at the multipoint portion.

  In the comparative example door mirror m2 shown in FIG. 23, the flow from the front pillar 11 and the flow flowing along the inner side of the mirror housing interfere with each other and strike the side window 3, resulting in a large wind noise. On the other hand, in the door mirror m1 of the embodiment shown in FIG. 22, the flow from the front pillar 11 and the flow flowing along the inner portion 7A of the mirror housing 7 are parallel flows, and the respective flows do not interfere with each other. The wind noise was able to be significantly reduced without causing a flow toward 3.

  FIG. 24 shows the analysis result of the speed change (intensity of disturbance) of the door mirror m1 of the example product, and FIG. 25 shows the analysis result of the speed change (intensity of disturbance) of the door mirror m2 of the comparative example product. However, in FIGS. 24 and 25, for convenience of illustration, as the hatching becomes denser, the change in speed increases, and the portion indicated by black fill shows that the change in speed is relatively maximum. .

  Here, the speed change is a gradient of the absolute value U of the velocity in the main flow direction x and can be expressed by dU / dx. The absolute value U of the velocity is expressed by the following [Equation 1].

但し、ｕ，ｖ，ｗは、それぞれ車両前後方向、車幅方向、鉛直方向の流れの速度を示す。

However, u, v, and w indicate the flow speed in the vehicle longitudinal direction, the vehicle width direction, and the vertical direction, respectively.

  In comparison with FIG. 24 and FIG. 25, it is clear that the door mirror m1 of the example product is less disturbing than the door mirror m2 of the comparative example product.

  FIG. 26 shows an analysis result of excessive distribution of the door mirror m1 of the example product, and FIG. 27 shows an analysis result of excessive distribution of the door mirror m2 of the comparative example product. However, in FIG. 26 and FIG. 27, for convenience of illustration, as the hatching becomes denser, the excess becomes larger, and the portion indicated by the black fill shows that the excess becomes relatively maximum.

  Here, the above-mentioned excess is closely related to the velocity gradient, and generally, when the velocity gradient (change) increases, the excess increases, and this excess causes the flow disturbance most directly. It is a scale that expresses automatically.

  In the door mirror m2 of the comparative example shown in FIG. 27, the vortex caused by the front pillar 11 and the vortex caused by the mirror housing 7 interfere with each other, and wind noise and air resistance are deteriorated. On the other hand, in the door mirror m1 of the embodiment shown in FIG. 26, the interference between the vortex caused by the front pillar 11 and the vortex caused by the mirror housing 7 can be eliminated. Can be greatly reduced.

  Next, the door mirror m3 of the example product shown in FIG. 28 (a), the door mirror m4 of the comparative example shown in FIG. 28 (b), and the door mirror m5 of the comparative example shown in FIG. In addition, about 25 small-diameter through holes are provided in the side window evenly distributed in the region of the side window 3 shown in FIG. 3, and a pressure sensor is inserted into the through hole from the inside of the window, so that the pressure on the surface of the side window 3 is increased. The result of having measured distribution is shown (refer FIGS. 29-31).

  However, as an example of the door mirror m3, as shown in FIG. 28 (a), the vertical width w1 of the stay portion 5 is about 23% with respect to the vertical height of the central portion of the mirror housing 7 in the vehicle width direction. A model was used. Further, as a door mirror m4 of the comparative example, as shown in FIG. 28 (b), a door mirror model in which the vertical width w2 of the stay portion 5 is about 65% with respect to the vertical height at the center in the vehicle width direction of the mirror housing 7. Was used. Furthermore, as the door mirror m5 of the comparative example, as shown in FIG. 28 (C), a door mirror model in which the vertical width w3 of the stay portion 5 is about 67% with respect to the vertical height at the center in the vehicle width direction of the mirror housing 7. Was used.

  29 shows the measurement result of the pressure fluctuation distribution of the door mirror m3 of the example product, FIG. 30 shows the measurement result of the pressure fluctuation distribution of the door mirror m4 of the comparative example product, and FIG. 31 shows the pressure fluctuation of the door mirror m5 of the comparative product. The measurement result of distribution is shown. However, in FIG. 29 to FIG. 31, for the sake of convenience of illustration, as the hatching becomes denser, the pressure fluctuation on the surface of the side window 3 increases, and the blacked portion indicates that the pressure fluctuation is relatively maximum. Yes.

  As apparent from the comparison of these figures, the vertical width of the stay portion 5 becomes excessive (see FIGS. 28B and 28C) and the depth DE of the air flow path 13 (see FIG. 4) becomes excessively small. It has been found that the flow is turbulent, the pressure fluctuations become stronger, and the wind noise gets worse.

  Although illustration of the measurement result is omitted, the flow rate increases as the vertical width w of the stay portion 5 becomes smaller than the structure of FIG. 28A and the depth DE of the air flow path 13 becomes excessive. It was also found that the pressure fluctuation increased with an excessive increase.

  Therefore, the vertical width w of the stay portion 5 is a predetermined width at which the upper end 5a of the stay portion 5 is positioned below the height center line L8 of the mirror housing 7, as already shown in FIGS. The depth DE of the air flow path 13 is preferably set to be larger than the vertical width w of the stay portion 5 in order to reduce pressure fluctuation and reduce wind noise.

    As described above, the door mirror device of the above embodiment includes the mirror base portion 4 provided in the triangular region at the front end of the side window 3 at the front end portion of the belt line 2 of the side door 1, and the vehicle width direction from the mirror base portion 4. A door mirror device for an automobile comprising a stay portion 5 protruding outward and a mirror housing 7 attached to the stay portion 5 and containing a mirror 6, which faces the mirror base portion 4 of the mirror housing 7. The inner part 7A is formed in a substantially flat shape, and an air flow path 13 is formed between the mirror base part 4 and the inner part 7A above the stay part 5, and the air flow path 13 is viewed from the front of the vehicle (FIG. 4). In the reference), the mirror base portion 4 and the inner portion 7A of the mirror housing 7 are formed in an inverted trapezoidal shape having a wide upper portion.

  According to this configuration, the above-described air flow path 13 has an inverted trapezoidal shape when viewed from the front, that is, an upwardly widened shape having a base of a predetermined length, and faces the mirror base portion 4 of the mirror housing 7. Since the inner portion 7A to be formed is substantially planar, a flow passage cross section without a narrow portion such as an inverted acute triangular shape is formed linearly and continuously in the front-rear direction, and flows through the air flow passage 13 Can be prevented from being deflected and hitting the side window 3, and turbulence behind the air flow path 13 can be suppressed. As a result, it is possible to reduce the wind noise and the Cd value.

  Further, as shown in FIG. 4, the inner portion 7A of the mirror housing 7 is set so as to spread upward at an angle θ7 of 5 to 15 degrees with respect to the vehicle vertical direction (see the vehicle vertical direction line L7). It is.

  According to this configuration, wind noise can be reduced most by setting the angle θ7 of 5 to 15 degrees. That is, when the angle θ7 exceeds 15 degrees, the turbulence generated in the air flow path 13 decreases, and the wind noise and Cd value tend to decrease, but the air flow rate passing through the air flow path 13 increases, Wind noise and Cd value deteriorate. Furthermore, the cross section in the vehicle width direction of the air flow path 13 is wider at the top and narrower toward the bottom, so that the lower flow velocity is larger than the upper flow velocity, and a velocity gradient is formed in the vertical direction of the air flow passage. Then, a vortex resulting from this velocity gradient is generated. Wind noise and Cd value are also deteriorated due to this vortex. On the other hand, when the angle θ7 is less than 5 degrees, the cross section in the vehicle width direction of the air flow path is a vertically elongated rectangular shape, and the mirror base portion and the inner side of the mirror housing extend over the air flow path 13. Since they are close to each other, the flow on the front pillar 11 side and the flow on the mirror housing 7 side easily interfere with each other, and a vortex is generated to deteriorate the wind noise and the Cd value. Therefore, the angle range is set.

Further, the depth DE of the air flow path 13 is set to be larger than the vertical width w of the stay portion 5 in a vehicle front view (see FIG. 4).
According to this configuration, an increase in the Cd value due to the vertical width w of the stay portion 5 can be prevented.

  In addition, at least the latter half of the air flow path 13 is formed so as to be wide toward the rear (see angle θ1) in plan view (see FIG. 5).

  According to this configuration, in addition to the above-described front view structure of the mirror housing 7, the plan view configuration of the air flow path 13 is configured so as to expand backward, so that the traveling wind passing through the air flow path 13 is mirrored. Flowing in parallel from the front of the vehicle toward the rear of the vehicle along the substantially planar inner portion 7A of the housing 7, without causing a flow toward the side window 3, and a rapid change in speed is eliminated. Interference between the vortex caused by the front pillar 11 and the vortex caused by the mirror housing 7 can be eliminated, whereby wind noise and air resistance caused by the door mirror can be greatly reduced.

Further, the front side portion 7B and the inner side portion 7A of the mirror housing 7 form a ridge line portion 14 having an acute angle θ2 in a horizontal section (see FIG. 5).
According to this configuration, since the ridge line portion 14 with the acute angle θ2 is formed, the traveling wind that collides with the front side portion 7B of the mirror housing 7 can be generated inside the mirror base portion 4 and the mirror housing 7 as compared with the case where the ridge line portion 14 is formed with an obtuse angle. Since it becomes difficult to be introduced into the gap (air flow path 13) between the portion 7A and the amount of air passing through the gap flow becomes small, the vortex caused by the mirror housing 7 becomes relatively small with respect to the gap flow.

Furthermore, as shown in FIG. 4, the vertical width w of the stay portion 5 is set to a predetermined width at which the upper end 5a of the stay portion 5 is positioned below the height center line L8 of the mirror housing 7. .
According to this configuration, it is possible to achieve both reduction in pressure fluctuation on the surface of the side window 3 and support rigidity of the mirror housing 7. That is, when the vertical width w of the stay portion 5 is excessively small and the depth DE of the air flow path 13 is excessive, the flow rate of air passing through the air flow path 13 increases and the pressure fluctuation on the surface of the side window 3 increases. Becomes larger and the support rigidity of the mirror housing 7 deteriorates. Conversely, when the vertical width w of the stay portion 5 is excessive and the depth DE of the air flow path 13 is excessive, the air flow passing through the air flow path 13 is likely to be disturbed, and Since the air resistance increases due to the width w, it is set as described above.

  As disclosed in the embodiment, the widening angle θ1 with respect to the vehicle longitudinal direction (see the vehicle longitudinal direction line L1) of at least the rear half of the inner portion 7A of the mirror housing 7 is 4 to 6 degrees, preferably θ1 = 5 degrees. When set to, the prevention of flow toward the side window 3, the elimination of sudden speed changes, the elimination of interference between the vortex of the front pillar 11 and the vortex of the mirror housing 7 are further improved, and wind noise and air resistance are further reduced. It was clarified by the above experiment and CFD analysis.

  Further, as disclosed in the embodiment, when the ridge line portion 14 formed by the inner side portion 7A and the front side portion 7B of the mirror housing 7 is formed to have a curvature radius R1 = 10 mm or less in a horizontal section (see FIG. 5), While satisfying the design requirements, traveling wind that collides with the front side portion 7B of the mirror housing 7 is less likely to be introduced into the gap (air flow path 13) between the mirror base portion 4 and the inner portion 7A of the mirror housing 7. At the same time, it is possible to suppress the disturbance of the gap flow caused by the front end portion of the mirror housing.

  Further, as disclosed in the embodiment, the front side portion 7B of the mirror housing 7 is set to an angle θ3 (preferably θ3 = 22 ° ±) of 15 degrees or more from the vehicle width direction line L4 in the horizontal section shown in FIG. (1.5 °), the air resistance can be further reduced by the retracting structure of the front side portion 7B of the mirror housing 7 toward the outside of the vehicle.

  Further, as disclosed in the embodiment, when the opening angle portion θ4 that is wide at 20 degrees or less toward the front of the vehicle in a plan view is formed by the mirror base portion 4 and the front half portion of the inner portion 7A, the design requirement is satisfied. In addition, it is possible to achieve both reduction of wind noise and air resistance. That is, the above-mentioned opening angle portion θ4 is preferably about 5 degrees, but when the opening angle portion θ4 is set to 5 degrees, the appearance deteriorates, so that both design requirements and reduction of wind noise and air resistance are achieved. In the above, it is desirable to set θ4 = 20 degrees or less.

Front view of a vehicle equipped with a door mirror device of the present invention 1 is a plan view of the main part of FIG. Side view of the main part of FIG. Rear view showing the door mirror device as seen from the rear of the vehicle AA arrow view of FIG. The rear view of the door mirror apparatus seen from the arrow X direction of FIG. BB line view of FIG. CC arrow view of FIG. DD line view of FIG. 6 EE arrow view of FIG. GG arrow view of FIG. Top view of door mirror device H1-H1 line arrow figure of FIG. H2-H2 arrow view of FIG. H3-H3 arrow view of FIG. H4-H4 line arrow view of FIG. H5-H5 line arrow figure of FIG. H6-H6 line arrow figure of FIG. H7-H7 line arrow figure of FIG. H8-H8 arrow view of FIG. Plan view of the door mirror of the example product and the comparative product Explanatory drawing which shows the analysis result of the speed of the mainstream direction of an example product Explanatory drawing which shows the analysis result of the speed of the mainstream direction of a comparative example product Explanatory drawing which shows the analysis result of the speed change of the example product Explanatory drawing which shows the analysis result of the speed change of a comparative example product Explanatory drawing which shows the analysis result of excessive distribution of the example product Explanatory drawing which shows the analysis result of excessive distribution of a comparative example product Front view of the door mirror of the example product and comparative product Explanatory drawing which shows the measurement result of the pressure fluctuation distribution of the side window surface of the example product Explanatory drawing which shows the measurement result of the pressure fluctuation distribution of the side window surface of a comparative example product Explanatory drawing which shows the measurement result of the pressure fluctuation distribution of the side window surface of a comparative example product

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Side door 2 ... Belt line 3 ... Side window 4 ... Mirror base part 5 ... Stay part 5a ... Stay part upper end 6 ... Mirror 7 ... Mirror housing 7A ... Inner part 7B ... Front side part 13 ... Air flow path 14 ... Ridge part DE ... depth w ... vertical width L8 ... height center line

Claims (6)

A mirror base provided in a triangular region at the front end of the side window at the front end of the belt line of the side door;
A vehicle door mirror device comprising: a stay portion protruding outward in the vehicle width direction from the mirror base portion; and a mirror housing attached to the stay portion and containing a mirror,
The inner part facing the mirror base part of the mirror housing is formed in a substantially planar shape,
An air flow path is formed between the mirror base portion and the inner portion above the stay portion,
The air channel is a door mirror device formed in an inverted trapezoidal shape in which the upper part is wide between the mirror base part and the inner part of the mirror housing in a front view of the vehicle. The door mirror device according to claim 1, wherein an inner portion of the mirror housing is set to spread upward at an angle of 5 to 15 degrees with respect to the vehicle vertical direction. The door mirror device according to claim 1 or 2, wherein a depth of the air flow path is set to be larger than a vertical width of the stay portion in a front view of the vehicle. The door mirror device according to any one of claims 1 to 3, wherein at least a rear half portion of the air flow path is formed so as to be widened rearward in a plan view. The door mirror device according to any one of claims 1 to 4, wherein the front side portion and the inner side portion of the mirror housing form an acute ridge line portion in a horizontal section. The door mirror device according to any one of claims 1 to 5, wherein the upper and lower widths of the stay portion are set to a predetermined width at which an upper end of the stay portion is positioned lower than a height center line of the mirror housing.

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