JPH0978517A - Snow melting unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight snow melting unit facilitating the transportation and installation work by arranging linear heating elements each covered with a core wire made of carbon short fibers by an insulating cover material at proper intervals on a net woven by flexible cords into rough meshes. SOLUTION: Linear heating elements 2 are arranged at prescribed intervals on a net 1, and the net 1 is formed with cords made of a strong heat-resistant flexible raw material. A core wire made of carbon short fibers is covered by a water-resistant insulating cover material via a woven fabric or a braid made of heat-resistant fibers to form the linear heating element 2. A bundle of carbon fibers has a large heating area, and it has high heating efficiency because it emits far infrared rays. The net 1 is installed on the surface of the concrete or gravel face serving as the foundation bed of a road before asphalt is paved, then asphalt is paved to bury the net 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snow melting unit which is buried in a road in a snowfall region and used for melting snow accumulated on the road.

[0002]

2. Description of the Related Art In recent years, a linear heating element in which short carbon fibers are coated with an insulating coating has been popularized as an effective heat medium for a snow melting device on a road in a snowfall region, especially on a highway. This heating element is very effective in that it has excellent flexibility, strength and thermal efficiency, and can easily set a desired electric resistance value.

Such a linear heating element is used by embedding it in a pavement surface of a road. In order to correctly install and fix the linear heating element at a predetermined position at a predetermined interval, the surface of the road is conventionally fixed. Before paving with asphalt or other paving material, it is attached to the concrete surface of the base at regular intervals using appropriate fixing metal fittings. However, with this conventional means, a large number of fixing fittings have to be fixed to the base with screws or the like, and the work is very complicated and is a major obstacle.

[0004]

In view of the above problems, the present inventor has previously fixed linear heating elements to a porous sheet at regular intervals and fixed the sheet to the concrete surface before asphalt construction. We have previously proposed a means that allows the linear heating element to be correctly embedded at the set position simply by placing it on the.

However, it has been found that such a sheet material can penetrate only a part of the asphalt through the holes of the sheet when the asphalt is embedded, which hinders sufficient bonding between the concrete and the asphalt. In addition, due to the presence of the sheet material, the entire unit becomes bulky and its weight becomes heavy, which makes transportation and laying work on site difficult.

Therefore, according to the present invention, the linear heating elements can be correctly arranged at a preset interval simply by laying them on the concrete surface as a base before the asphalt construction. Without interfering with the connection between concrete and
Moreover, the main object of the present invention is to provide a snow melting unit which is lightweight and easy to carry and lay on site.

[0007]

In order to achieve the above object, the present invention takes the following technical means. That is, in the snow-melting unit according to the present invention, the linear shape in which the carbon short fiber is used as the core wire 2a and the core wire is covered with the insulating coating material 2b is provided on the upper surface of the net 1 woven with a relatively large mesh by a flexible cord. The heating element 2 has a structure in which it is attached at an appropriate interval.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below based on an embodiment shown in the drawings. FIG. 3 shows a linear heating element used in the present invention.
Is a short carbon fiber as a core wire 2a, and the core wire 2a is woven or braided with heat resistant fiber 2c to form a water resistant insulating coating material 2
It is covered with b. The core wire 2a is a bundle of carbon fibers, and has a large heat generation area, so that heat generation efficiency is good, and far infrared rays are emitted, so that heating efficiency is high. Further, it is very effective in that it has excellent flexibility and strength, and a desired electric resistance value can be easily set.

Therefore, in the present invention, the linear heating element 2 is
It is attached to the upper surface of the net 1 knitted with a relatively large mesh with a string at a predetermined interval. The string constituting the net 1 is formed of a strong and flexible material having heat resistance, and for example, a string braided with an aramid resin fiber and having a diameter of about 3 mm is preferable. The size of the mesh of the net is preferably about 10 cm on each side.

The binding force between the net 1 and the linear heating element 2 may be such that the net 1 and the linear heating element 2 are not separated during carrying or laying and can withstand the flow pressure when asphalt is poured. Therefore, as shown in FIG. 1, the connection between the two can be easily performed by knotting with the thread 3 or wire, a simple fastener, or high-frequency fusion.

In the embodiment shown in FIG. 1, the linear heating elements 2 meander on the net 1 and are arranged in series, but they may be arranged electrically in parallel.

The above-mentioned snow melting unit uses concrete 4 or gravel surface 5 asphalt on the base of the road.
Before being paved with, it is laid on the surface of concrete 4, and then paved with asphalt 5 and embedded. Of course, the linear heating element 2 has an outlet 7 formed at the end thereof connected to a power source in advance through a lead wire. Further, when the snow melting unit is laid on the concrete 4, the net 1 is placed in a tensioned state and the linear heating elements 2 are arranged at regular intervals. Therefore, it is advisable to fasten the four sides of the net to concrete with appropriate fasteners. See also net 1
In order to easily maintain the strength and maintain the tensioned posture, it is preferable that the string 1a on the outer circumference of the net 1 is made of a material that is stronger than the other strings.

FIG. 4 shows another embodiment of the linear heating element 2 used in the snow melting unit of the present invention.
a is formed by assembling a plurality of thin wire materials into one core wire. In the embodiment shown in FIG. 3, short carbon fibers are aggregated and directly formed into a single core wire. Therefore, the diameter of the core wire is likely to be uneven over the entire length, and the strength is poor, but In the embodiment of FIG. 4, although the core wire is formed of aggregated bundles of short carbon fibers as a whole, the diameter of the core wire can be made uniform over the entire length, and thus the electric resistance in each part is equalized. As a result, it is possible to obtain a linear heating element having high quality and strength while preventing uneven heat generation and abnormal heat generation.

Although the embodiments considered to be typical of the present invention have been described above, the present invention is not necessarily limited to the structures of these embodiments, and the constitutional requirements are provided.
In addition, the object of the present invention can be achieved and the invention can be appropriately modified and carried out within the range in which the following effects are exhibited.

[0015]

As described above, according to the present invention, since the linear heating elements are attached to the upper surface of the net knitted with the relatively large mesh by the flexible cord at appropriate intervals, the asphalt construction is performed. By simply laying the net on the concrete surface that is the base, the linear heating elements can be correctly arranged at preset intervals, which can facilitate the construction and reduce the cost, and Asphalt is completely in contact with the base concrete surface through a large mesh, which prevents the asphalt from joining the concrete due to the presence of the snow melting unit. It has various remarkable effects such as being easy.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a snow melting unit according to the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line AA in FIG.

FIG. 3 is a perspective view showing the structure of a linear heating element according to the present invention.

FIG. 4 is a perspective view showing another embodiment of the linear heating element of the present invention.

FIG. 5 is a cross-sectional view showing a usage example of the snow melting unit of the present invention.

[Explanation of symbols]

 1 sheet 2 linear heating element 2a core wire of linear heating element 2b coating of linear heating element 4 concrete 5 asphalt

Claims (1)

[Claims] 1. A linear heating element 2 in which a carbon short fiber is used as a core wire 2a and the core wire is covered with an insulating coating material 2b is provided on the upper surface of a net 1 knitted with a relatively large mesh by a flexible cord at an appropriate interval. A snow melting unit installed open.