JPH0832429B2 - High frequency welder welding method for composite sheets - Google Patents

Description

TECHNICAL FIELD The present invention relates to a high-frequency welder welding method in which a composite sheet is laminated on a core material and welded.

[Prior Art] Conventionally, when a composite sheet is laminated on a core material and welded using a high-frequency welder, the current between the electrodes of the high-frequency welder simply has a certain gradient as shown in FIG. It is changed by either the method of increasing and holding it for a while (B) or repeating the operation of increasing and holding a plurality of steps (C).

[Problems to be Solved by the Invention] In the method of simply increasing the current between the electrodes of the high-frequency welder with a certain gradient and maintaining the current constant for a while, if the current is increased, the degree of welding is improved, but sparks occur. Therefore, there is a problem that the composite sheet is damaged. The method in which the current is increased and the constant holding operation is repeated in a plurality of steps is remarkably improved in the generation of sparks and the damage to the composite sheet, but there is a problem in that the degree of welding varies. .

[Means for Solving Problems] The composite sheet according to the present invention for solving the above problems is laminated on the core material, and the current between the electrodes of the high-frequency welder to be welded is increased, and a constant holding operation is performed for a while. The high-frequency welder welding method for a composite sheet consists of repeating and increasing the number of steps to increase the current, repeat the operation of holding the current constant for a number of times, then reduce the current once, hold it for a while, and then increase it again. The feature is that it is held constant for a while.

[Operation] When a composite sheet is laminated on a core material by using the present invention and welded, sparks are not generated and the composite sheet is not damaged, and variations in the degree of fusion of the composite sheet to the core material are drastically reduced.

[Embodiment] An embodiment of the present invention will be described with reference to the drawings.

First, FIG. 2 shows a state in which a composite sheet 2 made of foamed PVC 2a and cloth 2b is laminated on the core material 1 and inserted between the electrodes 4 and 5 of the high frequency welder. The high frequency welder comprises a high frequency generator 3 and a lower electrode 4 and an upper electrode 5 connected to the high frequency generator 3. The lower electrode 4 has a shape corresponding to the pattern of the welding line of the composite sheet 2, is erected on the aluminum substrate 6, has its upper part projected, and is covered with the insulating material 7. The upper electrode 5 has a flat plate shape, and the upper electrode 5 is insulated from the aluminum substrate 6 and is configured to be movable up and down along a vertically installed guide post 8 so that the material to be set is sandwiched between the upper and lower electrodes. There is.

With respect to the core material 1 and the composite material 2 set as described above, the upper electrode 5 is lowered, and the high frequency voltage generated by the high frequency generator 3 is clamped between the lower electrode 4 and both electrodes. High frequency current. Figure 1 shows time on the horizontal axis,
The current is plotted on the vertical axis, and the current increase / decrease schedule is shown. That is, as shown by the line A, the current first increases,
The composite sheet 2 is temporarily welded three times and increased, the composite sheet 2 is primarily welded, and the composite sheet 2 is temporarily reduced, and the composite sheet 2 is temporarily held. In addition, increase the current again, close to the current peak before current reduction,
Or set it to a value slightly higher than that, and hold it gradually constant,
The composite sheet 2 is completely welded and fixed to the core material 1.

In order to prevent sparks, the gradient of current increase needs to be gentle.

In particular, in order to improve the degree of welding and to eliminate variations in the composite sheet 2 with low density and variations in density, which consists of foamed PVC 2a and cloth 2b, use a schedule with at least two current peaks. Needs to be welded.

[Effects of the Invention] As described above, the current increase / decrease schedule of the present invention,
In particular, by lowering the current once increased and then increasing it again to form two peaks of current, damage to the composite sheet 2 due to spark generation can be prevented, and the degree of welding to the upper core material 1 can be increased. The reliability of the high-frequency welder welding method for a sheet can be significantly improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of the current increase / decrease schedule of the present invention, and FIG. 2 is a cross-sectional view showing how the core material and the composite sheet are attached to the high frequency welder. 1 …… Core material 2 …… Composite sheet 2a …… Foam PVC 2b …… Cloth 3 …… High frequency generator 4 …… Lower electrode 5 …… Upper current 6 …… Aluminum substrate 7 …… Insulating material 8 …… Guide Post A ... Current change schedule of the present invention B, C ... Conventional current change schedule

Claims (1)

[Claims] 1. A high-frequency welder welding method for a composite sheet, comprising: stacking a composite sheet on a core material; increasing a current between electrodes of a high-frequency welder to be welded; Increase in current,
A method for welding a high-frequency welder to a composite sheet, which comprises repeating a plurality of steps of a constant holding operation for a while, temporarily reducing the current, holding the current for a while, then increasing it and holding it for a while again.