JP2003138525A - Blowoff type snow fence - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the visibility of a driver by improving blowoff effect of a blowoff type snow fence. SOLUTION: Multiple vane type snow protection plates 13 are vertically installed at some intervals apart between supports 12 erected along the windward-side side edge of a road and inclined so as to make the blow-in side higher than the other. The cross section of the vane type snow protection plates 13 is made into a downward projecting shape. A dynamic lift heading downward the windward produced in the vane type snow protection plate has an effect of preventing the vane type blowoff plates from being blown away. The air flow accelerates to a sufficiently long distance in the height of the eyes of the driver or less so as to produce the blowoff effect to the long distance. This constitution can prevent a bounding phenomenon by a fierce blow of the wind passing through the vane type snow protection plates against the road surface so as to prevent the visibility impediment of the driver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is installed along a road in a snowy region and uses wind to blow off snow on the road.
In addition, the present invention relates to a blow-off type snow fence that prevents visibility problems due to snow.

[0002]

2. Description of the Related Art As a snow fence to be installed along a road in a snowy region, for example, as shown in FIG. 11, a plurality of wings are provided between columns 2 which are erected at intervals along the windward side edge of the road 1. There is a blow-off type snow protection fence 4 in which type snow protection plates 3 are vertically spaced and inclined so that the wind blowing side (left side in FIG. 11) is inclined. This blow-off type snow fence 4 deflects the wind passing through the gap between the upper and lower wing type snow-proof plates 3 to a downwardly inclined flow and blows it down to the road surface. The snow that has accumulated on the road is blown away, and the snow that flies from the windward is pushed down to the driver's (vehicle driver's) eye height h = 1.35 meters or less to prevent the driver from having a visibility problem.

In this type of conventional blow-off type snow fence 4, the wing type snow plate 2 has an upwardly convex shape as shown in the drawing (Japanese Patent Laid-Open No. Hei 1 (1999) -58).
No. 0-338909, J. Kaikai 62-38916, etc.). In addition, there is also a mere flat snow-preventing plate, and there is also a wing type snow-preventing plate (see Japanese Patent Laid-Open No. 10-292319) in which the blowing side is convex upward and the blowing side is convex downward. There is no downward convex shape, and at least a downward convex shape on the wind blowing side is not used. This is because when you want to obtain a downward wind (blow-off wind) by deflecting the horizontal wind downward with the wing type snow plow, in order to make such a flow This is because it is a common sense and natural idea to have a convex wing shape.

[0004]

However, in the conventional wing-type snow protection plate 2 having an upward convex shape, as shown in FIG. 11, the wind blowing wind hits the road surface, strongly bounces, and the snow on the road rises, resulting in visibility. It tends to be defective, and the driver's line-of-sight height h =
There is a problem that the visibility at around 1.35 meters is not good. Although such a problem will be described later in detail together with the case of the present invention, it is shown in FIG. 8 which is a photograph at the time of a smoke wind tunnel test for the conventional blow-off type snow fence 4. Further, when the wind-blown wind strongly bounces on the road surface, the horizontal speed cannot be maintained to a long distance, and therefore the blowable distance L becomes short. In addition, with this type of blow-off type snow fence, the driver can see the scenery outside the fence through the gaps between the wing-type snow fences 3. Has a large projected area in the horizontal direction and a small gap between the wing type snow protection plates 3, so that the driver does not have good visibility through the snow protection fence.

Further, in the upward convex wing type snow plate, a lift force which is upward in the leeward direction is generated similarly to the lift force acting on the wing of the airplane. Therefore, this lift force is added to the wind resistance, and the wing type snow plate has a large force. There is a risk that the wing-type snow protection plate will come off the prop and be blown off due to the load.

The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and it is possible to increase the blowable distance over which the snow on the road surface can be blown off, and the visibility problem for the driver occurs. Can also prevent
It is an object of the present invention to provide a blow-off type snow fence which has a good view through the snow fence for the driver and which does not have the possibility of blowing off the wing type snow plates by the wind.

[0007]

In order to solve the above-mentioned problems, the blow-off type snow fence of the present invention comprises a plurality of wing-type snow-preventing plates between columns which are erected at intervals along the windward side edge of a road. The wing-type snow protection plate is characterized in that it is attached at an interval vertically and is tilted so that the blowing side becomes higher, and the cross-sectional shape of this wing type snow protection plate is downwardly convex.

According to a second aspect of the present invention, in the blow-off type snow fence, the inclination angle θ of the wing type snow plaque is set to be smaller at higher heights.

According to a third aspect of the present invention, in the blow-off type snow fence of the first aspect, the wing-type snow plate is provided with hook portions bent downward on the outer surface of the side plates fixed to both ends of the snow plate body. It is characterized in that the hook portion is fitted into the cylindrical receiving portion provided in the above, and is prevented from coming off, and is attached to the column.

According to a fourth aspect of the present invention, in the blow-off type snow fence, the sizes of the left and right hook portions of the wing type snow protection plate are different from each other.

According to a fifth aspect of the present invention, in the blow-off type snow fence of the first aspect, the wing-type snow protection plate is formed by sequentially bending a plurality of parts in the width direction of one plate to form a downward convex shape. Is characterized by.

According to a sixth aspect of the present invention, in the blow-off type snow fence, the wing type snow plate has a cross-sectional shape in which an upper end edge thereof is folded up and a lower end edge thereof is folded down. To do.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
~ It demonstrates with reference to FIG. FIG. 1 (a) is a simplified front view showing a span portion of the blow-off type snow fence 11 according to the embodiment of the present invention, and FIG. 1 (b) is a sectional view taken along the line A-A of (a). As shown, the blow-off snow protection fence 11 of this embodiment
Is, for example, four wing-type snow protection plates 13 are vertically spaced between the pillars 12 standing upright along the road 1 on the windward side in the width direction of the road 1 (on the left side of FIG. 1B), And the blowing side (Fig. 1
It is attached so that (left) in (b) is higher.

In the present invention, the wing type snow protection plate 13 has a downward convex shape as shown in the drawing. As shown in detail in FIGS. 3 and 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 downward convex shape. Is bent downward at a plurality of positions in the plate width direction to have a downwardly convex shape. The side plate 16
Is a bracket portion 16 having the same cross-sectional shape as the snow plate body
a, and the end of the snow plate main body 15 is fastened and fixed to the bracket portion 16a with a bolt 17 and a nut. Further, on the outer side surface of the side plate 16, as shown in FIG.
The 90 ° elbow 18a is provided with a hook portion 18 having a downward bent shape in which a small-diameter short pipe 18b is welded and fixed to one end of the 90 ° elbow 18a, while a U-shaped member 19a is welded and fixed to the column 12 side at a predetermined angle θ. The wing-shaped snow protection plate 13 forming the portion 19
The hook portion 18 on the side is fitted into the cylindrical receiving portion 19,
The retaining pin 20 is used to prevent retention, and the wing-type snow plate 13
Is attached to the column 12. Size (outer diameter) of the short pipe 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 fitted. As a result, it is possible to surely prevent the mistake of attaching the wing-type snow protection plate 13 to the left and right, that is, the mistake of attaching the wing-type snow protection plate 13 in a state of being turned upside down so as to be convex upward.

A specific example of the blow-off type snow fence 11 of the embodiment is as shown in FIG. The pillar 12 is made of H-shaped steel, and the pillar leg portion 12a is welded and fixed on the base plate 22 and the pillar body portion 12 to which the wing type snow protection plate 13 is attached.
b, and the lower end of the column main body 12b is rotatably connected to the column leg 12b by a hinge 12c. A holding portion 2 for accommodating and holding the wing type snow protection plate 13 in the pillar leg portion 12b during the summer when the blow-off snow protection fence 11 is not used.
3 is provided. In summer, attach each wing type snow plaque 13 to the prop 1.
2, the support body 12 is held by the holding portion 23.
B is bent at a right angle with a hinge 12c, and is blown off snow fence 1.
1. Make sure that the whole is folded so that it does not interfere with the driver's view. An anchor bolt 24 is embedded in concrete. Further, as shown in FIG. 5, the U-shaped member 19a forming the cylindrical receiving portion 19 is welded and fixed to a mounting plate 25 which is welded and fixed in the flange portion of the column 12 which is an H-shaped steel. The angle θ of the tubular receiving portion 19 becomes the inclination angle θ of the wing type snow protection plate 13. Also, the column 12
The upper parts of the are connected by a connecting member 26. The size of each part of the blow-off type snow fence 11 of the embodiment is a fence height H = 3.4.
m, the length of the wing type snow plate 13 is 3.73 m, the wing type snow plate 1
The height of the snow blade body 15 of No. 3 is 0.5 m, the interval between the upper and lower blade-type snow blades 13 is 0.64 m, and the height position of the blade-type snow blade 13 at the bottom is 1.15 m. The cross-sectional shape of the wing type snow protection plate 13 is the shape shown in FIG. As will be described later, the blow-off type snow fence used in the wind tunnel experiment is a 1/4 model of this size.

The operation principle of the wing type snow protection plate 13 in the blow-off type snow protection fence 11 will be described below.
If the inclination angle θ is small, the shielding property (the action of the wing-type snow protection plate 13 to block the wind) is enhanced, and the downward wind is strengthened.
Is large, the shielding property is small and the downward wind is weakened. Therefore, by adjusting the inclination angle θ for each one of the wing-type snow protection plates 13, the inclination angle θ is set to be small in the high places and set to be large in the low places to enhance the shielding performance and to blow up to a long distance. The payout effect can be sustained. For this reason, as shown in FIG. 1B, 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 such that the bottom stage has the maximum angle and the top stage has a smaller angle.

The results of wind tunnel experiments performed on the blow-off type snow fence of the present invention and the conventional blow-off type snow fence will be described. A smoke wind tunnel test and a large-scale wind tunnel experiment were performed for the blow-off type snow fence of the present invention, and only a smoke wind tunnel experiment was performed for the conventional blow-off type snow fence. In the large-scale wind tunnel experiment, a wind blow type snow fence (however, a 1/4 scale model of the above size) was installed in the wind tunnel, and the horizontal wind speed behind the wind blow type snow fence was measured with a hot wire anemometer.
As the conventional blow-off type snow fence, the wing-type snow plate 13 of the blow-off type snow fence 11 according to the embodiment of the present invention is attached upside down.

FIG. 7 is a photograph of the blow-off type snow fence 11 of the present invention at the time of a smoke-wind tunnel test, and FIG. 8 is a photograph of a conventional blow-off type snow fence at the time of a smoke-wind tunnel test. In the conventional method, the wind that has passed through the wing type snow plate is strongly blown against the road surface to bounce, whereas in the case of the present invention, such a phenomenon does not occur. The double circle seen in the photograph is not directly related to the matters described in this specification (the description is omitted).

FIG. 6 shows the results of a wind tunnel experiment on the blow-away snow protection fence 11 of the present invention, where the horizontal axis is a dimensionless speed which is the ratio of the speed of the wind applied to the blow-away snow protection fence 11, and the vertical axis is the wind speed. It is a ratio (Y / H) of the measured height position Y to the fence height H (= 3.4 meters). The position where the wind speed was measured is X = 0.61 as the distance X from the wind-blown snow fence 11.
H, X = 1.21H, X = 1.82H, X = 2.42
H, X = 3.03H, X = 3.64H, X = 4.24
H, X = 4.61H at 8 places, and the dimensionless height (Y / H) is 20 between 0.07 and 1.21.
The height position of the place is measured. The following can be seen from the wind velocity measurement results in FIG. In other words, if the driver's line-of-sight height (1.35 m) or higher, X =
The speed has been reduced to 0.8 or less until 4.61H. Note that this area is not particularly important in the present invention. Below the driver's line of sight, the speed is increased up to X = 3.64H (corresponding to a road width of 12.4m) (increased from 0.8).
And the effect of blowing off is obtained. From this,
The upper wing type snow protection plate 13 enhances the effect of blowing off the road portion close to the blow-off type snow protection fence 11, and the wing type snow protection plate 13 in the lower stage synergizes with the flow passing through the lower opening of the fence, and blows further away. It can be seen that the payment effect continues.

Further, the wing-shaped snow plate 13 which is convex downward is
Since the lift P directed to the windward downward direction is generated, it is possible to obtain the action of preventing the wing type snow protection plate 13 from being blown off by the resistance of the wind. The lift P is exactly the same as the principle of the upward lift acting on the wing of an upwardly convex airplane, but since it is downwardly convex, it is a downward lift.

In the present invention, the above-mentioned respective actions are synergistically utilized to reduce the horizontal projected area of the wing type snow protection plate 13, and hence to increase the gap between the wing type snow protection plates 13. Therefore, it is possible to significantly improve the driver's view through the snow fence. That is, as is clear from the comparison between FIG. 7 (present invention) and FIG. 8 (conventional example), which are photographs taken during the smoke wind tunnel test, even if the inclination angle of the wing type snow protection plate 13 is set larger than that of the conventional product (horizontal). Since it is possible to obtain a sufficient blow-off effect and to improve the visibility at the driver's line-of-sight position, the wing-type snow plate 13 has a larger inclination angle (horizontal angle) than the conventional wing-type snow plate. It is possible to reduce the horizontal projected area of the wing-type snow protection plate 13 by increasing the clearance between the wing-type snow protection plates 13 and to greatly improve the driver's view over the snow fence. .

As shown in FIG. 9, in order to increase the rigidity of the snow-prevention plate body 15 ', the cross-sectional shape in which the upper and lower edges of the snow-prevention plate body 15' are folded back (the folded-back portions are indicated by 15'a and 15'b). May be

The snow plate main body 15 'shown in FIG.
Although the folded portions 15'a and 15'b of the upper edge and the lower edge have a cross-sectional shape that is folded back to the upper side, the folded portion 15 "of the lower edge is 15" like the snow protection plate body 15 "shown in FIG. It is desirable that b has a cross-sectional shape folded back. This is because snow easily accumulates on the snow-prevention plate body 15 '(easily stays) at the folded-back portion 15'b that is folded back to the upper side of the lower edge as shown in FIG. 9, so that when the snow melts, water drops form from the lower edge. This is because it may drip or grow as fluff, which is not preferable.

The specific construction of the blow-off type snow fence of the present invention is not limited to that of the embodiment, and various design changes can be made. For example, it is naturally possible to form the convex cross-sectional shape under the wing type snow protection plate with a smooth curve. Further, in the embodiment, a wing-type snow protection plate that is convex downward is formed by pressing a plate having a certain thickness, but it may have a cross-sectional shape in which the thickness is changed like a wing of a general airplane. . Further, in the embodiment, the trailing edge side of the wing type snow protection plate 13 is made flat, but the trailing edge side (blowing side) may also have a downwardly convex cross-sectional shape.
In short, at least the front edge side (blowing side) may have a downward convex shape, and may have a downward convex cross-sectional shape as a whole. Further, the number of blade-type snow protection plates 13 is not limited to four, and can be increased or decreased as appropriate. Further, the structure for attaching the wing-type snow protection plate 13 to the column 12 is not limited to that of the embodiment, and any structure is possible, and the tilt angle θ can be adjusted. However, if the inclination angle θ is set to an appropriate value in consideration of various conditions such as the weather at the installation location, there is little need for subsequent readjustment. Therefore, the inclination angle θ is fixed as in the embodiment. No problem. Further, as the material of the wing type snow protection plate 13, a steel plate such as a galvanized steel plate is usually used, but it may be made of plastic.

[0025]

EFFECTS OF THE INVENTION According to the present invention, a plurality of wing-type snow protection plates are attached to a column with a vertical interval and inclined so that the blowing side is higher, and the cross-sectional shape of the wing-type snow protection plates is changed. Since the shape is convex downward, the following effects can be obtained. As is clear from the results of the wind tunnel experiment, at the driver's line of sight or below, the speed is increased sufficiently far (increased from 0.8), so that the blowing effect can be obtained far. Unlike the case of the conventional convex cross-sectional shape, the wind that has passed through the wing-type snow plate does not blow strongly against the road surface and bounces off, so that visibility problems for the driver can be prevented. Since the lift P directed to the windward downward direction is generated in the wing type snow protection plate, it is possible to prevent the wing type snow protection plate from being blown off by the resistance of the wind. The above-mentioned actions are synergistically utilized to reduce the horizontal projected area of the wing-type snow plaque, and thus to increase the gap between the wing-type snow plaques, and the driver's view over the snow fence. Can be significantly improved. By folding back the upper and lower edges of the wing type snow plate,
It is possible to improve the rigidity of the wing type snow protection plate, but in that case, if the folded-back portion of the lower end edge is folded back downward as in claim 6, it becomes easier for snow to accumulate on the snow-protection plate body. Not preferred.

[Brief description of drawings]

FIG. 1 is a view showing a blow-off type snow fence according to an embodiment of the present invention, (a) is a front view, and (b) is a sectional view taken along the line AA of (a).

FIG. 2 is a perspective view showing a detailed structure of the blow-off snow protection fence of FIG.

FIG. 3 is an enlarged view of part B in FIG.

FIG. 4 is an enlarged view of a C portion of FIG.

5 is a view on arrow D of FIG.

FIG. 6 is a graph showing the results of a wind tunnel test on the above-mentioned blow-off type snow fence, and is a graph showing the relationship between the height position at each position in the road width direction and the wind speed (all are dimensionless).

FIG. 7 is a photograph taken during a smoke wind tunnel test on the above-mentioned blow-off snow protection fence.

FIG. 8 is a photograph taken during a smoke wind tunnel test on a conventional blow-off type snow fence.

FIG. 9 shows another embodiment of the wing type snow protection plate and is a view corresponding to FIG. 4.

FIG. 10 shows still another embodiment of the wing-type snow protection plate, in which the fold-back of the lower edge of the wing-type snow protection plate in FIG. 9 is reversed.

FIG. 11 is a view schematically showing a conventional blow-off snow protection fence and its operation.

[Explanation of symbols]

1 road 11 Blow-off type snow fence 12 props 13 wing type snow plate 15, 15 ', 15 "snow plate body 15'a, 15'b, 15 "b folding part 16 side plate 16a Bracket part 17 Volts 18 Hook part 19 Cylindrical receiving part 20 retaining pin 25 Mounting plate 26 Connection member

Claims (6)

[Claims] 1. A plurality of wing-type snow protection plates are vertically spaced between struts that are erected at intervals along the windward side edge of a road, and are inclined so that the blowing side becomes higher. A blow-off snow fence that is attached and has a wing-shaped snow plate with a convex downward cross-section. 2. The blow-off snow protection fence according to claim 1, wherein the wing-type snow protection plate is set to have a smaller inclination angle θ at a higher place. 3. The wing type snow protection plate comprises hook portions bent downward on the outer surface of side plates fixed to both ends of the snow protection plate main body, and the hook portions are fitted into a cylindrical receiving portion provided on the column side. The blow-off snow protection fence according to claim 1, wherein the snow-proof fence is attached to a support after being prevented from coming off. 4. The blow-off snow fence as claimed in claim 3, wherein the left and right hook portions of the wing type snow guard have different sizes. 5. The blow-off snow protection plate according to claim 1, wherein the blade-type snow protection plate is formed by sequentially bending a plurality of portions in a plate width direction to form a downward convex shape. fence. 6. The blow-off snow fence as claimed in claim 1, wherein the wing type snow plaque has a cross-sectional shape in which an upper end of the wing is folded up and a lower end of the wing is folded down.