JPS5856661B2 - Genatsuzou Keiyo Film Harihouhou Narabini Souchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a film tensioning method and apparatus for vacuum molding, which can prevent film tearing during film tensioning work during vacuum mold making.

Conventionally, when applying film in vacuum molding, if the model used has many split surfaces, the film would be abnormally sucked through the gaps between the model split surfaces and be torn due to an increase in the degree of model vacuum immediately after the film was applied.

For this reason, it would be best to reduce the gap between the models to about 0.1 to 0.3 mm, but if the gap between the models is made this small, it will be difficult to remove the mold after it has been made. It was extremely difficult to secure a gap of 0.1 to 0.3 peaks in complex models.

In order to solve the above-mentioned problems, the present invention aims to provide a method and apparatus for applying a film for vacuum molding, which can suppress the increase in the degree of vacuum immediately after applying the film and prevent the film from tearing. , its characteristics are that when applying film during vacuum molding,
At the same time as completing the film installation, the degree of vacuum in the model vacuum box was reduced to 15.
0 to 200mrILHg, and a switch installed on the film tensioning surface of the vacuum box closes the pressure force of the film as soon as the film is tensioned, and the vacuum level is controlled by a switch provided in the communication path between the vacuum box and the vacuum pump. The present invention is configured to control the degree of pressure reduction in the model pressure reduction box to a desired degree by throttling the regulating valve.

Hereinafter, specific embodiments of the apparatus capable of carrying out the method of the present invention will be described based on the drawings. In the drawings, 1 is a model with many split surfaces, and 2 is a model with a degree of vacuum of 200 m71L.
Hj! Decompression box connected to the above vacuum pump, 3 is a gap in the model, 4 and 5 are solenoid valves for adjusting the degree of decompression, 6 is decompression box 2
7 is a film;
9 is a communication pipe.

When applying the film 7 to the model 1, the switch 6 is pressed by the film 7 as soon as the film is applied, and the solenoid valve 4 narrows the cross-sectional area of the communication pipe 8 at a preset ratio, and at the same time The valve 5 also reduces the cross-sectional area of the communication pipe 9 at a preset ratio, and the degree of vacuum inside the model 1 is maintained at 150 to 200 from immediately after the film is applied to when the model is removed.
This suppresses and maintains m71LHg.

The cross-sectional areas of the pipes 8 and 9 of the electromagnetic valves 4 and 5 are individually set depending on the size of the model 1 and the difference in the 100% plane of the model.

In this way, as soon as the film tension is finished, this film 7
When the solenoid valves 4 and 5 for adjusting the degree of depressurization are throttled using the switch 6, which operates in response to the push force of ~
It can be reliably suppressed to 200 mmHg,
In addition, since the amount of air sucked into the vacuum pump from the decompression box 2 is saved, as is clear from the table below, even if the gap 3 of the model 10 is widened to 0.5 to 1, the film 7 will not be torn. The good result was that there was no at all.

Particularly, according to the present invention, since the film is applied at a high degree of vacuum of 200 mrnH9 or higher, the film can be applied in a short time and in a secure manner.
J, even if a film is applied to a model with many complex split surfaces, the film can be prevented from tearing in the same manner as in the above embodiment. It exhibits a remarkable effect where the film stretches the most, and the gap in this type of model can be widened to about 1n, making it extremely easy to cut out the mold after molding. This method has an excellent effect in that it can be used even on models for which it was not possible to use the method.

[Brief explanation of drawings]

The drawing shows an example of an apparatus implementing the method of this invention. 1... Model, 2... Decompression box, 4, 5... Decompression degree adjustment valve, 6... Switch, 7... Film.

Claims (1)

[Scope of Claims] 1. When applying a film to a model having a gap in the cut surface using a vacuum pump with a degree of decompression of 200mMg or more, the model decompression box is activated in conjunction with the film application completion detection means at the same time as the film application is completed. A method for applying a film for vacuum molding, characterized by controlling the degree of vacuum to 150 to 200 mrE9. 2 A switch installed on the film tensioning surface of the pressure reduction box closes the film's pressure receiver at the same time as the film tension is completed, and the pressure reduction degree adjusting valve provided in the communication path between the pressure reduction box and the vacuum pump is closed. A film tensioning device for vacuum molding, characterized in that it is configured to control the degree of vacuum in a model vacuum box as desired.