JPH025508Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heating device for rubber/plastic materials, which heats an object to be heated, such as a cable sheathing material, by dielectric heating using microwaves.

[Prior Art] For example, when connecting power cables, heating is often required to soften the insulation or shrink the Lylar tape. However, recently, the use of fire has become prohibited in sealed and closed spaces such as manholes and tunnels to prevent fires, making it impossible to use gas burners, for example. Therefore, instead of using a gas burner, it is necessary to mainly use hot air heating using an electric heating wire, but this electric heating wire can also lead to a fire depending on how it is used, so safety must be taken into consideration. For example, even with hot air from a heating wire, if a limited area is heated intensively for a long period of time, there is a sufficient risk of ignition. Furthermore, since the cable sheathing material is thick, it cannot be heated in a short time only with hot air from a heating wire, and work efficiency tends to decrease.

[Purpose of the invention] In order to solve these demands, the purpose of the invention is to develop a rubber material that can efficiently heat even thick materials without using fire by dielectric heating using microwaves.
An object of the present invention is to provide a heating device for plastic materials.

[Summary of the invention] The gist of the invention to achieve the above objectives is as follows:
The container has at least one approximately circular cross section, serves as a reflector and is provided with a microwave incidence port, and covers a part of the elongated object to be heated, and has an entrance and exit for the object to be heated. This heating device for rubber/plastic materials is characterized in that a microwave shielding plate is disposed to close the gap between the entrance and exit, and the object to be heated is heated while preventing microwaves from leaking to the outside.

[Embodiments of the invention] The invention will be described in detail based on illustrated embodiments.

In Fig. 1, reference numeral 1 denotes an object to be heated, such as a reinforcing edge at the connection part of a rubber/plastic insulated power cable, which is made of rubber/plastic material such as the covering material of the cable to be heated, and a cylindrical shape is formed around it. A shield container 2 is constructed. This container 2 has a cylindrical portion 3 with a small diameter at both ends surrounding the object to be heated 1, but the object to be heated 1 may be inserted into the interior through this cylindrical portion 3, or the container 2 may be inserted into the cylindrical portion 3. It may be divided into two parts and placed over the object to be heated 1. The inner surface of the container 2 also serves as a microwave reflector, and a multilayer shielding plate 4 made of a metal plate or wire mesh is arranged inside the cylindrical part 3 to prevent microwaves from leaking to the outside. . Further, a microwave generator 5 is attached to a part of the container 2, so that microwaves are guided into the container 2 from a microwave incidence port 6 provided in the container 2. A diffusion plate 7 for diffusing the microwave is provided inside the entrance 6.

Therefore, the microwaves that have propagated from the microwave generator 5 into the container 2 are diffused by the diffusion plate 7, reflected on the inside of the container 2, uniformly concentrated on the object to be heated 1, and absorbed inside. The object to be heated 1 will be heated. For example, when the heated object 1 is a power cable, the insulating layer itself made of rubber or plastic material is also heated, but the insulating layer is heated by heating the semiconducting layer with microwaves. be able to. Further, the cylindrical part 3, which is the entrance/exit for the object to be heated 1 into the container 2, is provided with shielding plates 4 for shielding and absorbing microwaves. Since it is formed in a step-like manner, microwaves are effectively absorbed and are less likely to leak outside.

FIG. 2 shows another embodiment, in which the container 2
is considered to be a sphere. Therefore, the microwaves tend to concentrate in the center of the spherical container 2, and the temperature of the heated object 1 also increases significantly in that part.

3 shows the diffuser plate 7 having a chevron-shaped cross section, and FIGS. 4a and 4b show modified examples of the diffuser plate 7, respectively. By appropriately changing the shape of the diffusion plate 7 in this way, the heating characteristics of the object to be heated 1 can be adjusted according to the material, properties, etc. of the object to be heated 1.

In addition, in the embodiment, the microwave generator 5
Although one unit is used, a plurality of these may be attached to the container 2, or microwaves may be introduced into the container 2 from multiple locations from one generator 5 using a microwave waveguide. can. In addition, as shown in FIG. 5, the microwave incidence port is oriented obliquely so that the microwaves do not proceed directly toward the object to be heated 1, and the diffuser plate 7 is omitted or its size is reduced. It is also possible to do so. In addition,
The same effect can be obtained even if the cross section of the container 2 is not perfectly circular, for example, it is circular.

[Effects of the invention] As explained above, the heating device for rubber/plastic materials according to the invention can achieve heating by concentrating microwaves on the object to be heated in the center of the container.
It can heat objects efficiently and is designed to prevent microwaves from escaping to the outside.

[Brief explanation of the drawing]

The drawings show an embodiment of the heating device for rubber/plastic materials according to the present invention, FIG. 1 a is a longitudinal sectional view thereof, b is a cross sectional view, FIG. is a cross-sectional view, FIGS. 3 and 5 are cross-sectional views of still other embodiments, and FIGS. 4a and 4b are cross-sectional views of the diffuser plate. Code 1 is the object to be heated, 2 is the container, 3 is the cylindrical part, 4
5 is a shielding plate, 5 is a microwave generator, 6 is an entrance port, and 7 is a diffuser plate.

Claims (1)

[Claims for Utility Model Registration] 1. The object to be heated is placed in a container which has at least one section approximately circular, which also serves as a reflector and is provided with a microwave incidence port, and which covers a part of the elongated object to be heated. A rubber/plastic material characterized by having an entrance/exit and arranging a microwave shielding plate that closes the gap between the object to be heated and the entrance/exit to heat the object while preventing microwaves from leaking to the outside. heating device. 2. The heating device for rubber/plastic materials according to claim 1, wherein the container is spherical. 3. The heating device for rubber/plastic materials according to claim 1, which is provided with a diffusion plate for diffusing microwaves inside the entrance of the container.