JP2019210791A - Snow protection plate continuous inclined installation-type snow protection fence - Google Patents

Abstract

To provide a snow fence that minimizes the formation of snow hills.SOLUTION: In a snow fence comprising the installation of a plurality of main pillars standing on a ground with a plurality of snow prevention plates installed between the main pillars, the arrangement of the snow prevention plates in a plan view is provided in a continuous inclined arrangement.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a snow fence having a snow board arranged continuously obliquely in plan view.

  Conventionally, various types of snow fences have been widely used. However, as shown in the present invention, there are currently no snow fences arranged in a diagonal direction.

Many snow fences are provided on the side of the road to prevent snow accumulation on the road during winter snowfall. Conventional snow fences use horizontal snow guards and are arranged linearly in plan view. Due to the structure, the snow fences on the leeward side (road side) are affected by the wind direction and wind speed. Accumulation has occurred and traffic obstruction has become a problem.
In view of the above, the present invention has been invented in order to solve the above-described problems by providing a snowboard with a continuous oblique arrangement.

The present invention has the following configuration as means for solving the problems.
That is, in the snow fence which is provided with a plurality of main pillars standing on the ground and provided with a plurality of snow protection boards between the main pillars, the snow protection board arrangement in a plan view is provided in a continuous oblique arrangement.
The present invention is a snowproof plate continuous obliquely arranged snowproof fence having the above-described configuration.

According to the present invention, unlike the conventional snow protection fence using a linear arrangement in plan view and a horizontal type of snow prevention plate, the snow prevention plate has a configuration using a continuous oblique arrangement. The airflow after passing through the board does not flow to the vicinity of the snow fence as in the past, but is attracted by the wind flowing through the upper layer of the snow fence and merges with the upper airflow, preventing the occurrence of local puddles. In addition, a useful and novel snow fence that can minimize the formation of snow hills can be obtained.
Further, the plane view angles of the upper and lower frames can be appropriately selected and manufactured in consideration of the installation space.

Plan view of the present invention Front view of the present invention Right side view of the present invention Explanatory drawing of essential parts of the present invention (plan view) Installation explanatory diagram of the present invention (continuous connection state) Installation explanatory diagram of the present invention (description of each part) Airflow explanatory diagram when using the present invention (right side view) Airflow explanatory diagram when using the present invention (plan view) Explanatory drawing of formation snow hill when using the present invention Explanatory drawing of formation snow hill when using the present invention Configuration diagram of conventional example (front view) Airflow explanatory diagram when using the conventional example (right side view) Airflow explanatory diagram when using the conventional example (plan view) Explanatory drawing of formation snow hill when using conventional example Snowproof plate arrangement angle explanatory diagram of the present invention Example of change of snowproof plate arrangement of the present invention Example of change of snowproof plate arrangement of the present invention Example of change of snowproof plate arrangement of the present invention Example of change of snowproof plate arrangement of the present invention

Hereinafter, embodiments of the present invention will be described.
In the figure, reference numeral 1 denotes a main pillar, which is an H-shaped steel standing on a concrete foundation buried in the ground with its upper surface exposed, and is firmly fixed on the foundation with anchor bolts.
Reference numeral 2 denotes an upper frame, which is a substantially L-shaped portion in plan view formed by cutting a pair of angle steel materials obliquely and joining the cut surfaces by welding. It is fixed to the upper part by appropriate means. Reference numeral 3 denotes a lower frame, which is the same member as the upper frame, and is fixed to the lower side of the main pillar side surface.
4 is a perforated snow-proof board. This perforated snowproof plate is formed by drilling a number of holes in a long metal plate that is bent into a substantially trapezoidal shape in plan view, and between the upper frame and the lower frame, the ground is in the vertical direction, Further, the frame is fixed to each frame with bolts and nuts along the shape of the frame in plan view, that is, in a continuous oblique arrangement in which the upper right and the lower right are continuous.
A plurality of the perforated snow protection plates are fixed in the vicinity of the tops of the upper and lower frames symmetrically in front view. Reference numeral 5 denotes a non-perforated snowproof plate, the overall shape of which is the same as that of the perforated snowproof plate, but no holes are provided. A plurality of non-perforated snow plates are provided between the upper and lower frames in the same manner as the perforated snow plates, and between the vicinity of the main pillar and the perforated snow plate.
Reference numeral 6 denotes an intermediate reinforcing plate which is a flat plate provided horizontally between the main pillars at an intermediate position between the upper frame and the lower frame, and each snow protection plate is fixed to the reinforcing plate. Reference numeral 7 denotes a lower reinforcement stay, which is a member that is passed and fixed from the position near the center of the lower frame to the middle position of the main pillar as shown in the figure, and stably reinforces the snow fence.

First, the structure, function, and problem of the conventional example will be described.
As described above, the snow protection plate used in the conventional snow fence is a horizontal type and has a linear arrangement in plan view. The majority of snow fences (spray fences) in Japan have a height of about 4 meters. This is set on the basis of the annual snow depth and the amount of accumulated snow. In general, a perforated snow plate is used at the top of the fence, and a non-perforated plate is used for the others. The use of a perforated plate at the top of the fence is to reduce the wind resistance on the road side by reducing the wind resistance at the top of the fence by reducing the compression resistance due to the wind, and the windward snow hill (hill-like This is to reduce the snow accumulation area) and to reduce the blizzard that blows from the edge of the fence to the road side. However, it is easy for snow to collect on the road side due to the snow blowing from the perforated plate.

The snow guard is a structure that is attached to the side, but in the snow fence with a fence height of 4 meters, the boundary position between the non-perforated board and the perforated board is 2.84 meters, and the top of the windward snow hill is at this height. When it reaches, the snow depth in the flatland is about 0.56 meters, which is about one fifth of the apex height.
The time when the flat snow depth reaches this level is around early January in Hokkaido. Since the snowstorm at this time directly hits the perforated plate and passes through, the snowstorm that has blown through stalls and accumulates in the immediate vicinity of the fence, so the lee snow hill grows rapidly and accumulates, and the state of poor visibility It becomes.
The response from February to the end of March, when snow and snowstorms occur, is extremely strict, and the snow fences have the opposite effect, creating a large pool on the road.

The mechanism of the conventional snow fence is influenced by the fast flow passing over the fence, and the wind on the road side is attracted in the direction of the fast wind, resulting in a flow opposite to the main wind direction. A big vortex is created in the direction of the top edge of the snow fence, and it carries snow in the direction of the fence so as to stroke the road surface.
Also, the snow on the road continues to flutter due to eddy currents, and the visibility becomes poor as if it was foggy.
In the case of a slant wind, the wind flows in the direction along the fence and the influence from the edge of the fence is large.
In strong winds, vortices are drawn even more violently along the fence, creating snow dunes that block the road.

The causes of snow hills formed near the fence are as follows. That is, as shown in FIG. 12, the fast airflow over the fence flows continuously toward the upper part of the fence in the direction opposite to the main wind direction, and the snow contained in the wind is separated from the wind to the road side. Approaching the fence, a triangular snow hill is formed.
In addition, when the distance from the road is short, it is affected by the fast wind blowing from the edge of the fence, and the wind flowing along the fence is sucked by the fast wind and engulfs the snowstorm on the road, resulting in a triangular snow hill Grows into larger shapes.

Attempts have also been made to solve the above problems. It is designed to suppress the wind from the center of the fence to the edge of the fence by connecting a plurality of elongated resistance plates that are arranged along the fence above and below the snow fence. Thus, the entrainment from the left and right ends of the fence is attenuated.
However, due to its structure, it becomes an overhanging beam and cannot be made too long due to the action of torsional moment. Therefore, the wind flows through the resistance plate, so the wind flowing along the fence is not changed and its effect is weak.

Next, the fence configuration and mechanism of the present invention will be described.
As shown in FIG. 2, the snowproof plate is configured to be mounted vertically. Moreover, it is a continuous diagonal arrangement | positioning in planar view as shown in FIG. A perforated plate is placed in the center of the frame in plan view, and the wind speed is low on the leeward side. The triangular space (the line connecting the snow fence fence apex from the center of the road or the edge of the road near the snow fence) The snow dancing on the snow fence and the ground is always supplied in the vertical direction, but the wind speed is low. Snow flying in a triangular space near the snow fence as viewed from the side of the snow fence joins the upper air stream so that it can be sucked by the fast wind flowing through the upper fence.
Therefore, contrary to conventional snow fences, the upward vector is a high snow density portion that becomes an upper layer flow, moves to the leeward side, prevents the occurrence of local puddles, and scatters over a wide area.
Further, the entrainment blown out from the end of the fence is an improvement of about 90% compared to the conventional snow fence because the wind flowing in the direction along the fence is attenuated.

When compared with the flat snow depth under the same conditions as the conventional snow fence, the original effect of the snow fence can be maintained even with a similar snow depth without changing the cross section of the vertical snow plate.
Therefore, the downwind snow hill on the road side is small, and a stable effect can be expected throughout the year.
Although there is a large vortex on the road, there is no problem because the wind speed is extremely low and the snow concentration is low.
In the case of slant wind, the wind that flows along the fence attenuates for each frame, so the wind blown from the edge of the fence is weak and has a filter function, so the accumulation at the edge of the fence is greatly improved. The slanted puddle formed on the road is eliminated. In the case of strong winds, they are sucked up and diffused by the wind at the top of the fence. Therefore, the formation of snow hills like a conventional snow fence can be reduced.

In the embodiment of the snow fence according to the present invention, the shape is a triangular shape in plan view during one span (distance between main pillars), and the angle θ is about 33 degrees as shown in FIG.
This angle is from 20 degrees to 45 degrees in a substantially acceptable range, and preferably from 25 degrees to 40 degrees. If this angle is too large, it may protrude beyond the ground area of the fence. If the angle is too small, the airflow flowing along the fence will not be attenuated and snow may be trapped from the horizontal end of the snow fence. This is not preferable because it is advantageous for the formation of snow hills.
From the above, the aforementioned 33 degrees was used as the optimum angle in the present invention.

A suitable ratio of the perforated snowproof plate and the non-perforated snowproof plate in one span is between 3: 7 and 5: 5. If the perforated plate ratio is large, the airflow will escape from the perforated plate, and the snowproof effect will be reduced.
On the contrary, if the ratio of the perforated plate is small, the airflow passing through the perforated plate is reduced, so that the airflow blows from the upper end or both ends of the snow fence and becomes a fast flow, generating vortex and entraining snow.
That is, the airflow is drawn to this fast flow. An appropriate ratio to prevent these is the above ratio. In addition, the total hole area in the perforated snow protection plate is about 30% of the entire area of the snow protection plate. In the example of this invention, the perforated snow-proof board is arrange | positioned in the planar view top part in the snow fence, and its vicinity. The airflow is not always at right angles to the snow fence, but it is often an oblique wind. Even in the case of this slant wind, since the airflow passes through the perforated snow protection plate, the airflow is attenuated, and the effect of preventing snow hill formation is exhibited.

16 to 19 show another embodiment of the present invention.
In these figures, the hatched portion indicates the position of the perforated snowboard.
FIG. 16 shows an example using two triangular parts in one span, FIG. 17 shows an example using one oblique part in one span, FIG. 18 shows an example of an unequal triangular shape in plan view, and FIG. This is an example in which the arrangement of the snow protection plate in plan view is an arc shape. The above shows an example of the change of the present invention, and a similar effect can be obtained although the shape is different from the first example. In the example, the vertical snow plate is used, but a horizontal snow plate may be used if the snow plate hole position is the same.
As described above, the present invention has been described, but the present invention has the feature that the snow protection plate is arranged in a continuous oblique arrangement in a plan view, compared to the case in which a conventional horizontal snow protection plate is used and arranged in a straight line in plan view, As described above, it has an advantageous effect in terms of snow hill formation and securing visibility.
Note that the above-described example is an example of implementation and may have other approximate configurations.
As described above, a snow fence configuration effective in the present invention can be obtained.

DESCRIPTION OF SYMBOLS 1 Main pillar 2 Upper frame 3 Lower frame 4 Perforated snow prevention board 5 Non-perforated snow prevention board 6 Intermediate reinforcement board 7 Lower reinforcement stay (theta) Snow prevention board angle used for this invention

Claims (2)

In the snow fence which is provided with a plurality of main pillars standing on the ground and provided with a plurality of snow prevention boards between the main pillars, the arrangement of the snow prevention boards in a plan view is provided in a continuous oblique arrangement. Features a snowboard continuous slanting snow fence. The snowproof plate continuous obliquely arranged snowproof fence according to claim 1, wherein the snowproof plate is provided in a direction perpendicular to the ground.