JP3946011B2 - Snow blow fence - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a blow-off type snow fence that is installed along a road in a snowy region, blows off snow on the road using wind, and prevents the occurrence of visibility problems due to snow.
[0002]
[Prior art]
As a snow fence to be installed along a road in a snowy region, for example, as shown in FIG. 12, a plurality of wing-type snow protection plates 3 are provided between struts 2 standing at intervals along the windward side edge of the road 1. There is a blown-off type snow fence 4 that is attached so as to be vertically spaced and inclined so that the wind blowing side (left side in FIG. 12) becomes higher. This blow-off type snow fence 4 deflects the wind passing through the gap between the upper and lower wing-type snow guards 3 to a slanting downward flow and blows it down on the road surface. The snow accumulated on the wind is blown away, and the snow flying from the windward is pushed down to the driver's (vehicle driver's) height h = 1.35 m or less to prevent the visibility of the driver from being disturbed.
[0003]
In this type of conventional snow blow fence 4, the shape of the wing type snow protection plate 2 is convex upward as shown in the figure (see Japanese Patent Laid-Open Nos. 10-338909, 62-38916, etc.). ing. There is also a simple flat snow plate, and there is a wing type snow plate having a convex shape on the blowing side and a convex shape on the blowing side (see JP-A-10-292319). There are no downward convex shapes, and at least the wind blowing side convex downward shape is not used. This is because when a horizontal wind is deflected downward by a wing type snowbreak plate to obtain a downward wind (blow-off wind), the wing type snowbreak plate must be This is because it is a common-sense and natural idea to have a convex wing shape.
[0004]
[Problems to be solved by the invention]
However, as shown in FIG. 12, in the conventional wing type snowbreak plate 2 having an upwardly convex shape, the wind blows against the road surface and bounces strongly, so that the snow on the road rises easily, resulting in poor visibility. There is a problem that visibility in the vicinity of h = 1.35 meters is not good. Although such a problem will be described later in detail in conjunction with the case of the present invention, it is shown in FIG. 9 which is a photograph at the time of a wind tunnel experiment for the conventional blown snow fence 4.
In addition, when the blow-off wind bounces strongly on the road surface, the horizontal speed cannot be maintained far, so the distance L that can be blown off becomes short.
In this type of blown snow fence, the driver can view the scenery outside the fence through the gap between the wing type snow guards 3. The projected area in the horizontal direction is large and the gap between the wing-type snow protection plates 3 is small, so the driver's view through the snow fence is not good.
[0005]
In addition, the upwardly convex wing type snowbreak plate generates upward lift on the leeward side, similar to the lift force acting on the wing of an airplane, so this lift is added to the wind resistance and a large load acts on the wing type snowbreak plate. However, there is a risk that the wing-type snow protection plate may be removed from the support and blown away.
[0006]
The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and can increase the distance that can be blown off the snow on the road surface, and also prevents the occurrence of visibility problems for the driver. Another object of the present invention is to provide a blow-off type snow fence that has good prospects for the driver over the snow fence and that does not cause the wing-type snow board to be blown off by the wind.
[0007]
[Means for Solving the Problems]
The blow-off type snow fence according to the present invention that solves the above-described problem is a plurality of wing-type snow guards spaced vertically between struts erected along the windward side edge of an automobile road. In addition, the airfoil side is inclined so that the blowing side is higher, the cross-sectional shape of the wing-type snowboard is convex downward , and the wing-type snowboard has a small inclination angle θ that is high. The thing of the low place is characterized by being big .
[0008]
According to a second aspect of the present invention, in the blow-off type snow fence according to the first aspect, the inclination angle θ of the wing-type snow protection plate is set to be smaller as the height is higher.
[0009]
According to a third aspect of the present invention, in the blow-off type snow protection fence according to the first aspect, the wing-type snow protection plate is provided with a hook portion bent downward on the outer side surface of the side plate fixed to both ends of the snow protection plate body, and provided on the support column side. The hook portion is fitted into a cylindrical receiving portion, is prevented from coming off, and is attached to a support column.
[0010]
According to a fourth aspect of the present invention, in the blow-off type snow fence according to the third aspect, the sizes of the left and right hook portions of the wing type snow protection plate are made different from each other.
[0011]
A fifth aspect of the present invention is the blow-off type snow fence according to the first aspect, wherein the wing-type snow protection plate is formed by bending a plurality of locations in the plate width direction of a single plate in order to form a downward convex shape. To do.
[0012]
According to a sixth aspect of the present invention, in the blow-off type snow fence according to the first or fifth aspect, the wing-type snow protection plate has a cross-sectional shape in which an upper end edge is folded upward and a lower end edge is folded downward.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 (a) is a front view showing, in a simplified manner, one span portion of the blow-off type snow fence 11 according to one embodiment of the present invention, and FIG. 1 (b) is a cross-sectional view taken along line AA in FIG. As shown in the figure, the blow-off type snow fence 11 according to this embodiment includes, for example, 4 between columns 12 erected along the road 1 on the upwind side in the width direction of the road 1 (left side in FIG. 1B). The wing-type snow-prevention plates 13 are attached so as to incline so that the blowing side (left side in FIG. 1 (b)) becomes higher with a gap in the vertical direction.
[0014]
In the present invention, the wing-type snow plate 13 has a downwardly convex shape as shown. As shown in FIG. 3 and FIG. 4, the wing-type snow protection plate 13 of the embodiment has a configuration in which side plates 16 are fixed to both ends of a snow protection plate body 15 having a downwardly convex shape. Are bent in order at a plurality of locations in the plate width direction to have a convex shape. The side plate 16 includes a bracket portion 16a having the same cross-sectional shape as that of the snow plate main body 15, and an end portion of the snow plate main body 15 is fastened and fixed to the bracket portion 16a with a bolt 17 and a nut. Further, as shown in FIG. 5, the side plate 16 is provided with a downward bent hook portion 18 having a small-diameter short pipe 18b welded to one end of a 90 ° elbow 18a, as shown in FIG. The U-shaped member 19a is welded and fixed at a predetermined angle θ to form the cylindrical receiving portion 19, and the hook portion 18 on the wing-type snow protection plate 13 side is fitted into the cylindrical receiving portion 19 so as to prevent the retaining pin. At 20, a wing-type snow protection plate 13 is attached to the support 12.
The sizes (outer diameters) of the short pipes 18b of the left and right hook portions 18 of the wing-type snow protection plate 13 are different from each other, and the sizes of the left and right U-shaped members 19a are also changed according to the short pipe 18b to be inserted. Yes. Thereby, the mistake which attaches the wing | blade type | mold snowproof board 13 right and left reversely, ie, the mistake which reverses up and down, and attaches in the state which becomes convex upwards can be prevented reliably.
[0015]
A specific example of the blown snow fence 11 according to the embodiment is as shown in FIG. The column 12 is made of H-shaped steel, and is composed of a column leg 12a welded and fixed on the base plate 22 and a column body 12b to which the wing-type snow plate 13 is attached. The lower end of the column body 12b is a column leg. The part 12b is rotatably connected by a hinge 12c. The support leg part 12b is provided with a holding part 23 for storing and holding the wing-type snow protection board 13 in summer when the blown snow protection fence 11 is not used. In summer, each wing-type snow protection plate 13 is removed from the support column 12 and held by the holding unit 23, and the support column body unit 12b is bent at a right angle by a hinge 12c so that the entire blow-off type snow protection fence 11 is folded. Keep out of the driver's sight. Reference numeral 24 denotes an anchor bolt embedded in the concrete.
Further, as shown in FIG. 5, the U-shaped member 19a that forms the cylindrical receiving portion 19 is welded and fixed to a mounting plate 25 that is welded and fixed in the flange portion of the column 12 that is H-shaped steel. The angle θ of the cylindrical receiving portion 19 becomes the inclination angle θ of the wing-type snow protection plate 13. Further, the upper portions of the columns 12 are connected by a connecting member 26.
The dimensions of each part of the blow-off type snow fence 11 according to the embodiment are as follows: the height of the fence H = 3.4 m, the length of the wing type snow protection board 13 is 3.73 m, and the height of the snow protection board body 15 of the wing type snow protection board 13. 0.5 m, the distance between the upper and lower wing-type snowboards 13 is 0.64 m, and the height position of the lowermost wing-type snowboard 13 is 1.15 m. The cross-sectional shape of the wing-type snowproof plate 13 is the shape shown in FIG. As will be described later, the blown snow fence used in the wind tunnel experiment is a 1/4 model of this size.
[0016]
The operation principle of the wing-type snow protection plate 13 in the above-described snowblower 11 will be described. When the inclination angle θ of the wing-type snow protection plate 13 is small, the shielding property (the action of the wing-type snow protection plate 13 blocking the wind) is enhanced. When the downward wind is strengthened and the inclination angle θ is large, the shielding property is reduced and the downward wind is weakened. Therefore, the inclination angle θ is adjusted for each of the wing-type snow protection plates 13, and the shielding angle is increased by increasing the inclination angle θ at a high place and increasing the inclination angle θ at a low place. The payment effect can be sustained. For this reason, as shown in FIG. 1 (b), the angle (inclination angle) θ of each of the four stages of the wing-type snow protection plate 13 with respect to the support column 12 is set to the maximum at the lowest stage and is set to be smaller at the upper stage.
[0017]
The result of having conducted the wind tunnel experiment about the blowing type snow fence of this invention and the conventional blowing type snow fence is demonstrated. A wind tunnel experiment and a large wind tunnel experiment were conducted for the blow-off type snow fence of the present invention, and only a smoke tunnel experiment was conducted for the conventional blow-type snow fence. In the large wind tunnel experiment, a blow-off type snow fence (however, a 1/4 model of the above-mentioned size) was installed in the wind tunnel, and the horizontal wind speed behind the blow-off type snow fence was measured with a hot wire anemometer. As the conventional blown-type snow fence, a wing-type snow plate 13 of the blown-type snow fence 11 according to the embodiment of the present invention was used upside down.
[0018]
FIG. 8 is a photograph at the time of a smoke tunnel test for the blow-off type snow fence 11 according to the present invention, and FIG. 9 is a photograph at the time of a smoke tunnel test for a conventional blow-type snow fence. In the conventional method, the wind that has passed through the wing-type snow protection board bounces strongly against the road surface and bounces, whereas in the case of the present invention, it can be seen that such a phenomenon does not occur. Note that the double circles visible in the photographs are not directly related to the matters described in this specification (description is omitted).
[0019]
FIG. 7 shows wind tunnel test results for the blown snow fence 11 according to the present invention. The horizontal axis represents a dimensionless speed that is a ratio to the wind speed applied to the blown snow fence 11 and the vertical axis represents the wind speed measurement height. The ratio (Y / H) of the position Y to the fence height H (= 3.4 meters).
The position at which the wind speed was measured is the distance X from the blown-off snow fence 11 as X = 0.61H, X = 1.21H, X = 1.82H, X = 2.42H, X = 3.03H, X = 3.64H, X = 4.24H, X = 4.61H, each of which has 20 heights between dimensionless height (Y / H) of 0.07 and 1.21. The position is measured. The following can be understood from the wind speed measurement result of FIG. That is,
(1) At the driver's eye level (1.35 m) or more, the speed is reduced to 0.8 or less until X = 4.61H. This area is not particularly important in the present invention.
(2) Below the driver's line of sight, the speed increased to X = 3.64H (corresponding to a road width of 12.4 m) (increased from 0.8), and a blowing effect was obtained.
From this, the effect of the upper wing type snow protection plate 13 blowing off the road portion close to the blown snow protection fence 11 is enhanced, and the lower wing type snow protection plate 13 has a synergistic effect with the flow passing through the lower fence opening, It can be seen that the blow-off effect has been sustained farther away.
[0020]
As shown in FIG. 6, the flow along the lower surface of the wing-shaped snow proof plate 13 that protrudes downward in the blow-off type snow protection fence 11 as shown in FIG. The wing-type snow protection plate 13 is separated from the wing-type snow protection plate 13 slightly before the end of the wing-type snow protection plate 13 (point E). Therefore, it is possible to blow down downward by Δθ smaller than the inclination angle θ of the wing-type snow protection plate 13. This is clearly shown in the flow along the lower surface of the uppermost wing-type snowproof plate 13 in FIG.
Therefore, when the down angle is constant, the inclination angle θ of the wing-type snow protection plate 13 can be set larger (closer to the horizontal), and the snow prevention of the driver is improved while improving the shielding performance and the blowing performance. The prospects over the fence can be improved.
Further, when the inclination angle θ of the wing-type snowproof plate 13 is increased (approached horizontally), the projected area in the wind direction is reduced (dimension “a” is reduced in FIG. 6). There is no risk of the board 13 blowing away.
In addition, the reduction of the wind load means that the horizontal load acting on the support 12 via the wing-type snow protection plate 13 is reduced, and the falling moment of the support 12 is reduced.
In addition, since the wing-type snow plate 13 generates a lift P (also see FIG. 6) toward the windward side, the wing-type snow plate 13 can be prevented from being blown off due to wind resistance. . The lift P is exactly the same as the principle of upward lift acting on the upwardly projecting wing of the airplane, but it is downward and therefore downward.
[0022]
In the present invention, the above-described actions are synergistically utilized to reduce the horizontal projection area of the wing-type snow protection plate 13, and thus the gap between the wing-type snow protection plates 13 can be increased. The prospects over snow fences can be greatly improved. That is, as is clear from a comparison between FIG. 8 (present invention) and FIG. 9 (conventional example), which is a photograph taken during a smoke tunnel experiment, even if the inclination angle of the wing-type snow protection plate 13 is set larger than the conventional product (horizontal However, it is possible to obtain a sufficient blow-off effect and to improve visibility of the driver's eye level, so that the wing-type snow plate 13 has a larger inclination angle (horizontal) than the conventional wing-type snow plate. The horizontal projection area of the wing-type snow protection plate 13 can be reduced, and therefore the gap between the wing-type snow protection plates 13 can be increased, and the driver's view through the snow protection fence can be greatly improved. .
[0023]
As shown in FIG. 10, in order to increase the rigidity of the snow plate main body 15 ′, the upper and lower edges of the snow plate main body 15 ′ may be folded back (folded portions are indicated by 15′a and 15′b). .
[0024]
10 has a cross-sectional shape in which the folded portions 15′a and 15′b at the upper end edge and the lower end edge are folded upward, but the snowproof plate shown in FIG. Like the main body 15 ", the folded portion 15" b at the lower end edge is desirably a sectional shape folded downward. This is because, as shown in FIG. 10, in the folded portion 15′b folded back to the upper side of the lower end edge, it is easy for snow to accumulate (is likely to stay) on the snow protection plate body 15 ′, so that when the snow melts, water drops from the lower end edge. Or it may grow as an icicle, which is not preferable.
[0025]
The specific configuration of the blow-off type snow fence of the present invention is not limited to the embodiment, and various design changes can be made. For example, it is naturally possible to form a convex cross-sectional shape with a smooth curve under the wing-type snowproof plate. Further, in the embodiment, a plate having a certain thickness is pressed to form a wing-shaped snow proof plate that protrudes downward. However, the cross-sectional shape may vary in thickness as in a general airplane wing. . Further, in the embodiment, the rear edge side of the wing-type snowproof plate 13 is flattened, but the rear edge side (blowout side) can also have a downwardly convex cross-sectional shape. In short, it is sufficient that at least the front edge side (blowing side) has a downwardly convex cross-sectional shape as a whole with a downwardly convex shape.
Moreover, the number of the wing-type snowproof boards 13 is not restricted to 4 steps | paragraphs, and can be increased / decreased suitably.
Moreover, the attachment structure to the support | pillar 12 of the wing | blade type | mold snowproof board 13 is not restricted to the thing of embodiment, Arbitrary, It can also be set as the structure which can adjust inclination | tilt angle (theta). However, if an appropriate inclination angle θ is set in consideration of various conditions such as the weather at the installation location, there is little need for subsequent readjustment, so the inclination angle θ is fixedly provided as in the embodiment. There is no problem.
Further, the material of the wing-type snow protection plate 13 is usually a steel plate such as a galvanized steel plate, but may be made of plastic.
[0026]
【The invention's effect】
According to the present invention, a plurality of wing-type snow protection plates are attached to the support column at an interval in the vertical direction and inclined so that the blowing side becomes higher, and the cross-sectional shape of the wing-type snow protection plate is a convex shape downward In addition, since the inclination angle θ of the wing type snow protection plate is small for the high place and large for the low place , the following effects can be obtained.
(1) Since the wind that has passed through the wing-type snow protection plate blows down at an angle smaller than the inclination angle θ of the wing-type snow protection plate, the inclination angle of the wing-type snow protection plate 13 can be set larger (closer to the horizontal). It is possible to improve the prospect of the driver through the snow fence while improving the shielding property to block the wind and the blowing property to blow off the snow on the road.
(2) Since the inclination angle θ of the wing type snow protection plate can be increased, the projected area in the wind direction can be reduced, thereby reducing the wind load, and the wing type snow protection plate may be blown away. Disappear.
(3) Since the wind load can be reduced, the horizontal load acting on the support via the wing-type snow protection plate can be reduced, and the falling moment of the support can be reduced .
(4) Since the lift force P is generated on the wing type snow protection plate in the downward direction on the windward side, it is possible to prevent the wing type snow protection plate from being blown off due to wind resistance.
(5) As clarified from the results of the wind tunnel test, the speed is sufficiently increased (increased from 0.8) below the height of the driver's line of sight, so that a blowing effect can be obtained far.
(6) Unlike the conventional upwardly convex cross-sectional shape, the wind that has passed through the wing-type snow protection plate does not cause a phenomenon of bouncing strongly against the road surface, so that it is possible to prevent the visibility of the driver from being disturbed.
(7) The above-mentioned actions are synergistically utilized to reduce the horizontal projection area of the wing-type snow protection plate, and therefore, the gap between the wing-type snow protection plates can be increased, so that the driver's snow fence The outlook can be greatly improved.
(8) The rigidity of the wing-type snow protection plate can be improved by folding back the upper edge and the lower edge of the wing-type snow protection plate. In this case, the folded portion of the lower edge is placed downward as in claim 6. A folded cross-sectional shape is preferable because it does not easily allow snow to accumulate on the snow protection plate body.
[Brief description of the drawings]
FIG. 1 shows a blow-off type snow fence according to an embodiment of the present invention, in which (A) is a front view and (B) is a cross-sectional view taken along line AA of (A).
2 is a perspective view showing a detailed structure of the blow-off type snow fence of FIG. 1. FIG.
FIG. 3 is an enlarged view of a portion B in FIG.
FIG. 4 is an enlarged view of a portion C in FIG.
FIG. 5 is a view taken in the direction of arrow D in FIG.
FIG. 6 is a view for explaining the action of a wing-type snow protection plate in the blow-off type snow protection fence.
FIG. 7 is a graph showing a wind tunnel test result for the blow-off type snow fence, and showing a relationship between a height position at each position in the road width direction and a wind speed (both non-dimensionalized).
FIG. 8 is a photograph taken at the time of a smoke tunnel test for the blow-off type snow fence.
FIG. 9 is a photograph taken at the time of a smoke tunnel test for a conventional snow blow fence.
FIG. 10 is a view corresponding to FIG. 4, showing another embodiment of the wing-type snowproof plate.
FIG. 11 shows still another embodiment of the wing-type snow protection plate, in which the lower end edge of the wing-type snow protection plate of FIG. 10 is turned upside down.
FIG. 12 is a diagram schematically showing a conventional blow-off type snow fence and its operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Road 11 Blow-off type snow fence 12 Support | pillar 13 Wing | blade type snow-protection board 15, 15 ', 15 "Snow-protection board main body 15'a, 15'b, 15" b Folding part 16 Side plate 16a Bracket part 17 Bolt 18 Hook part 19 Cylinder Shape receiving portion 20 Retaining pin 25 Mounting plate 26 Connecting member

Claims (6)

A plurality of wing-type snow protection boards are installed at intervals along the windward side edge of the road for automobiles at an interval so as to be vertically spaced and inclined so that the blowing side becomes higher. The airfoil snowboard has a cross-sectional shape that is convex downward , and the airfoil snowboard has an inclination angle θ that is small for high places and large for low places. Snowfall fence.   The blow-off type snow fence according to claim 1, wherein an inclination angle θ of the wing type snow protection plate is set to be smaller as a height is higher.   The wing type snow protection plate includes a hook portion bent downward on the outer side surface of the side plate fixed to both ends of the snow protection plate body, and the hook portion is fitted into a cylindrical receiving portion provided on the support column side to prevent the snow plate from coming off. The blow-off type snow fence according to claim 1, wherein the blow-off type snow fence is applied to the column.   The blow-off type snow fence according to claim 3, wherein the left and right hook portions of the wing-type snow board have different sizes.   The blow-off type snow fence according to claim 1, wherein the wing-type snow protection plate is formed by bending a plurality of portions in a plate width direction of a single plate in order to form a downward convex shape.   The blow-off type snow fence according to claim 1 or 5, wherein the wing-type snow protection plate has a cross-sectional shape in which an upper end edge is folded upward and a lower end edge is folded downward.

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