JPH04297699A - Sheet spreading disc and sheet spreading execution method - Google Patents

Abstract

PURPOSE:To facilitate welding execution of a sheet, not only avoid pendency, extension, thinning and damage caused by weight of the sheet based on heat melting up to an unnecessary additional are but also of a disc on a coating face of a difficult part of execution work corresponding to a sequestered place of the sheet. CONSTITUTION:An electromagnetic induction heating conductor 3 laminating heat welding compositions on both sides thereof is loaded to the surface of a heat melting disc 1 on which a heat welding sheet 2 has to be welded. The electromagnetic induction heating body 3 is fixed to a coating face, the sheet 2 is put on the surface of the induction heating body 3, the induction heating body 3 is heated form the surface side of the sheet by electromagnetic induction, and the sheet is welded to heating body by brining the sheet into contact with the heating conductor.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a sheet tensioning construction disc that can be attached to a covered construction surface, and more specifically, for example, when a heat-weldable waterproof sheet as a waterproofing material is stretched over a covered construction surface such as a tunnel. The present invention relates to a heat-welding disc that is used by being attached to a construction surface, and a sheet tension construction method that is attached to a covered construction surface.

0002

[Prior Art] Conventionally, for example, in order to stretch a waterproof sheet on the cladding surface of a tunnel, both the heat welding disc attached to the tunnel cladding surface and the waterproof sheet to be heat welded to it are simultaneously heated with hot air or electric heat. The waterproof sheet is then pressed onto the disc and welded. Although heating the tarpaulin with hot air is sufficient for heating the tarpaulin itself, the hot air is often blown onto the tarpaulin beyond the area to be welded. As a result, unnecessary portions of the waterproof sheet may be thermally melted, and those portions may be stretched downward by the weight of the sheet, resulting in thinning or damage. Heating with an electric heating iron does not thermally melt the tarpaulin over a wider area than hot air, but the tarpaulin tends to be insufficiently heated, often resulting in poor welding.

Recently, in order to solve these problems, a heating wire is interposed between the thermally welded disc on the tunnel covering surface and the waterproof sheet welded thereto, and the heating wire is energized to generate heat, and the disc is heated. Attempts have also been made to thermally melt and weld waterproof sheets. This specification allows the waterproof sheet to be thermally melted over the minimum necessary area, and is effective in avoiding drooping, thinning, and damage due to the weight of the waterproof sheet. However, it may be difficult to weld the tarpaulin sheet to a disc attached to the primary lining surface of a portion that is particularly far and recessed from the edge of the tarpaulin sheet. That is, the width of the tarpaulin sheet (in the tunnel length direction) is usually about 1.5 to 5 m.
It is large, with a length (tunnel cross-sectional direction) of approximately 10 to 30 m.
Among such dimensions, in the case of a disc on the covering surface of a large waterproof sheet corresponding to a recessed part, up to the disc,
The electric wires extending from the power supply through the gap between the waterproof sheet and the covered surface interfered with the welding of the waterproof sheet, making the work difficult. .

0004

[Problems to be Solved by the Invention] The problems to be solved are not only to avoid drooping and thinning of the waterproof sheet due to the weight of the waterproof sheet due to thermal melting in an excessive area, but also to avoid damage to the back side of the waterproof sheet. The above-mentioned type of sheet tensioning disc and sheet using the same can be easily welded with a waterproof sheet for discs on the covering surface of tunnels in areas corresponding to deep areas. The purpose is to develop a tensioning construction method.

[0005]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the first disc for sheet tension construction of the present invention is a heat-welding disc fixed to a coating work surface, and the heat-weldable sheet of the disc is fixed to a coating work surface. It is characterized in that an electromagnetic induction heating element having a heat-fusible composition laminated on the front and back surfaces is attached to the surface to be welded.

[0006] In the present invention, the heating element can be attached to a desired surface of the disk by using an adhesive, by causing the heating element to generate heat by induction heating, and by using a heat-fusible composition laminated on the heating element. It is possible to advantageously apply the specification of thermally melting and welding. It is sufficient to temporarily attach the heating element to the disk.

[0007] Furthermore, the second sheet tension construction method of the present invention is as follows:
An electromagnetic induction heating element is fixed to the coating surface, a sheet is stretched over the surface of the heating element, and the sheet is brought into contact with the heating element while heating and pressing the inductor from the upper surface of the sheet. It is characterized by being welded to the heating element.

[0008]

[Function] As described above, in the present invention, since the electromagnetic induction heating element having the heat-fusible composition laminated on the front and back surfaces is attached to the required surface of the disk, the front side of the sheet on which this heating element is stretched is attached. By generating heat using electromagnetic induction heating means, the heat-fusible composition laminated on the front and back surfaces of the heating element attached to the disk is melted, and the sheet to be heat-welded thereon is also heated in the required area. Can only be heat-fused. In addition, the amount of heat generated by the heating element should be set appropriately in design, depending on the current of the inductor that induction heats the heating element, the number of turns of the coil, the frequency of the applied high frequency, etc., or the high frequency application time of the inductor should be set appropriately. The sheet can be heated sufficiently and effectively by using the above-mentioned methods or both.

Thus, according to the present invention, drooping, thinning and damage due to the weight of the sheet due to thermal melting in an excessive area are avoided, and good welding of the sheet is ensured.

[0010] In the present invention, the use of an electromagnetic induction heating element attached to the disc to thermally melt the disc and the sheet is advantageous because the heating element on the side opposite to the disc on the coating surface (the surface side of the stretched sheet) By arranging an inductor and wiring for the inductor on the surface of the sheet, the heating element on the back side of the stretched sheet can generate heat. Therefore, it is possible to easily stretch the sheet on discs on the coating surface of the recessed portions of the sheet without being hindered by wiring for heating means as in the conventional method.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to the accompanying drawings, together with an example of the construction of a waterproof sheet in a tunnel according to the present invention. FIG. 1 is a cross-sectional view showing an embodiment of the present invention and a procedure for constructing a waterproof sheet in a tunnel using the disk of the present invention, and FIG. 2 is an inductor used to generate heat from a heating element in the disk of the present invention. FIG.

1 is a heat-weldable disc; 2 is a heat-weldable waterproof sheet welded to the disc 1 as a waterproofing material in a tunnel; A heating element 3 formed into a sheet by a mold and laminated with a heat-fusible composition (not shown) on its front and back surfaces is attached. It is sufficient to attach the heating element 3 to the disk 1 temporarily, and it may be done by an appropriate method such as using an adhesive.

As the heating element 3, a magnetic material or a conductive material can be used, and examples thereof include iron, aluminum, copper, stainless steel, brass, and resin in which ferromagnetic powder is uniformly mixed and dispersed. .

[0014] The disc 1 is attached with the side of the heating element 3 opposite to the coated surface 4 by any suitable method known per se, for example with nails 5.
It is fixed by hammering. Then, a weldable sheet is placed on the heating element, and the inductor 6 is brought into contact with the heating element 3 of the disc 1 on the tunnel covering surface 4 while pressing the sheet, and a high frequency is applied thereto by a high frequency oscillator 7. Then, the heating element 3 generates heat by induction heating.

In this way, the surface of the disc 1 to which the waterproof sheet 2 is to be welded (strictly speaking, the heat-weldable composition on the front and back surfaces of the heating element 3)
A waterproof sheet stretched over the surface of the disk 1 is thermally melted with the inductor 6 and the wiring 8 for it arranged on the upper surface of the waterproof sheet 2, and the disk 1 is heated. By pressing the waterproof sheet 2, this
Can be welded to.

In the present invention, the inductor 6 can advantageously be wound into a planar coil. This type of inductor can be fitted well along the disk 1, and is thin and occupies little space.

[0017]

As explained above, according to the present invention, it is possible to not only avoid drooping stretching and thinning due to the weight of the sheet and breakage due to heat melting in an excessive area, but also to solve problems in deep areas on the back side of the sheet. Even for disks on coated surfaces in areas where sheet installation is extremely difficult, the sheet can be easily welded without being hindered by the wiring for the heating means. Ru.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention and a procedure for constructing a waterproof sheet in a tunnel using the disc of the present invention.

FIG. 2 is a perspective view showing a preferred example of an inductor used to cause the heating element in the disc of the present invention to generate heat by electromagnetic induction.

[Explanation of symbols]

1 Jisk 2 Waterproof sheet 3 Heating element 4 Coated surface 6 Inductor 7 High frequency oscillator

Claims (2)

[Claims] 1. A heat-welding disc fixed to a coated surface, wherein an electromagnetic induction heating element having a heat-welding composition laminated on the front and back surfaces is attached to the face of the disc to which a heat-weldable sheet is to be welded. A disk for sheet tension construction, which is characterized by: 2. By fixing an electromagnetic induction heating element to a coated surface, stretching a sheet over the surface of the heating element, and pressing the inductor from the upper surface of the sheet, the sheet is brought into contact with the heating element. A sheet tension construction method, comprising welding the sheet to the heating element.