JP3711470B2 - Creeping, blown snow fence with guide plate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
It relates to a blow-off type snow fence that is installed for road traffic safety in snowy areas.
[0002]
[Prior art]
Snow fences used in snowy areas are installed on the windward side to prevent snow from accumulating on the road surface.Blow off type snow fences that blow the wind on the road surface to blow off the snow. There is a blow-off type snow fence that tries to reduce the snow that blows to the road side by accumulating snow on the windward side.
[0003]
In order to enhance the blow-off effect, the blow-off type often has a structure called creeping-up, in which the uppermost portion of the snow fence is inclined about 1/5.
[0004]
However, when the snow accumulation on the windward side increases and the height of the snow piles up, the snow trapping effect decreases, and the snow traps in the shadow of the turnover, and the field of view and snow accumulation begin to occur. Therefore, when installing this snow-preventing fence, it was supposed to be installed away from the road, not the shoulder of the road, but about twice the height of the fence, but there were many problems such as the acquisition of land.
[0005]
In order to solve this problem, as disclosed in Japanese Patent Application Laid-Open No. 2001-288715, it is composed of a vertical part in which a snow protection plate is raised vertically from below and an arcuate wing-type induction plate part that is curved upward on the upper side. A blown snow fence has been proposed.
[0006]
However, this invention is considered to be effective when snow is accumulated near the windward guide plate on the windward side of the snow fence, but when it is actually installed on a shoulder with a slope, it is immediately behind the snow fence. Even snow accumulation occurs.
[0007]
[Problems to be solved by the invention]
Even when there is little or no snow accumulation on the windward side of the snow fence, it does not cause snow accumulation or rolling up on the road, it can prevent road traffic trouble due to snow and can be installed on the shoulder A blown snow fence is desired.
[0008]
[Means for Solving the Problems]
The present invention has been made in view of the above problems, and is composed of three parts, a vertical rising part, a creeping part inclined to the leeward side, and a guiding part inclined further to the leeward side. A hole with a diameter of several centimeters is formed on one side of the snowproof plate of the guiding portion so that the opening area ratio is 20 to 40%.
[0009]
This hole guides a part of the wind to the back side of the snow protection plate to suppress the phenomenon of turbulent flow on the back side of the guiding part, that is, the leeward side, and stops the snow that exceeds the snow protection fence on the road behind the snow protection fence. It plays the role of blowing away far away.
[0010]
Embodiment
An example of the snow fence according to the present invention will be described with reference to the drawings. FIG. 1 is a side view showing the concept of the snow fence, and the left side of the figure corresponds to the windward side. A vertical section 1 with a height of 3.2 m, which is a stack of several snow protection boards with a width of 3.5 m, followed by a 0.6 m length with an inclination angle of 45 degrees that is horizontal toward the windward. The creeping part 2 is further composed of three parts: a wind and snow far overflow guiding part 3 having a slope angle of 60 degrees that is horizontal to the leeward, with a snow guard plate of 1.5 m in length, on top of it. The overall height is about 5 m. This snow fence is installed on the shoulder of the slope 4 on the road side, and there is a sidewalk 5 on the road side.
[0011]
Holes with a diameter of several centimeters are uniformly formed in the creeping part 2 and the guiding part 3 so that the total opening ratio is 30%. This is because when wind and snow crosses the guiding portion, turbulent entanglement causes a flow under the guiding plate so that the snow does not stagnate.
[0012]
Wind and snow are sprayed onto the snow fence from the left side of the figure. The snow is blocked by a snow fence and begins to pile up on the slope 4 on the lower left side of the vertical part 1 and gradually increases. And when the snow reaches the end of the wind, the wind and snow crosses the road of the snow fence, crosses the road, is blown to the opposite side of the road, and does not stop on the road.
[0013]
In order to verify this, a comparative model experiment using a wind tunnel was conducted on the snow fence of the present invention and two conventional snow fences. The wind tunnel is 0.7m high, 1m wide, and about 6m long. Activated white clay with a wind speed of 4.5m per second at a fineness of 200 mesh and 50% or more of activated white clay is thrown, and the height of the active white clay piled up before and after the 1/100 snow fence placed in the wind tunnel and the road model is constant. Measured every hour. The similarity between the actual and the model experiment has been verified.
[0014]
FIG. 3 shows the results of experiments conducted on three types of snow fences. a is a conventional snow fence with a creeping plate, b is a conventional snow fence with a guiding plate, c is a snow fence with a guiding plate and a guiding plate according to the present invention, and each of the snow fences has the same height. The slope angle of the slope is 1: 1.5, corresponding to the upper and lower steps 1m. A snow fence is installed on the shoulder, the wind blows from the left side, and the amount of deposition measured every 20 minutes is written in a broken line from the bottom. An outline of a conventional snow fence is shown in FIGS.
[0015]
From this experimental result, it can be understood that when the cracking of a reaches 60 minutes, the accumulation almost reaches the cracked area, and then the accumulation becomes more prominent, and the active white soil stops rapidly immediately behind the snow fence. That happened.
[0016]
In addition, b with the guide part reaches the upper part of the vertical part of the snow fence after 60 minutes, and the subsequent accumulation is not as noticeable as the creeping of a. However, the activated clay is still immediately behind the snow fence. Is starting to pile up.
[0017]
In the case of the snow fence with cue and guidance part of the present invention, the accumulation reaches the upper part of the vertical part after 60 minutes, and the accumulation continues in the same manner as b, but with other conventional snow fences The striking difference is that the backside of the snow fence has not progressed.
[0018]
【The invention's effect】
As described above, according to the snow fence of the present invention, it functions sufficiently as a blow-off type snow fence when there is little snow, and when the amount of snow exceeds a certain amount, it blows wind and snow far away on the road. It works to prevent snow from accumulating.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a snow fence according to the present invention.
FIG. 2 is a sectional view of another snow fence model used in the wind tunnel experiment. a: Conventional snow fence with creeping, b: Conventional snow fence with guide.
FIG. 3 shows the result of a wind tunnel experiment using a model. The amount of deposition every 20 minutes is indicated by a polygonal line from the bottom up to 20, 40, 60, and 80 minutes. a: Conventional snow guard fence with creeping-in, b: Snow guard fence with conventional guiding part, c: Snow fence with creeping-in and guiding part of the present invention. The unit is 1 for the height of the snow fence.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vertical part 2 Stealth part 3 Wind and snow far overflow guidance part 4 Road slope 5 Sidewalk

Claims (2)

In a snow fence with a total height of about 5m , the snow board is tilted at an angle of 45 degrees, and the vertical part where the snow board is raised up to a height of 3.2m in sequence from the bottom, and above it is horizontal toward the windward. A length of 0.6 m is used to guide the wind and snow away from the leeward side by inclining the snow-preventing plate above it to the opposite leeward side at an angle of 60 degrees with the horizontal . A blow-off type snow fence composed of three parts, a 5m guide part.   The blow-off type according to claim 1, wherein a hole having a diameter of several centimeters is uniformly formed in the snow-preventing plate of the creeping portion or further on the snow-preventing plate of the guiding portion so that the total opening ratio is 20 to 40%. Snow fence.

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