JPS6254657B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a thermoplastic resin fuel tank having an inner tank therein.

Conventionally, thermoplastic resin hollow molded products have shown great growth in various applications, but in the development of thermoplastic resin fuel tanks, we have developed thermoplastic resin fuel tanks that have the same functions as metal fuel tanks. The market situation is such that there is a demand for the development of a fuel tank with a high additional value that is equipped with an inner tank in which the liquid content is always present.

The inventors of the present invention conducted various studies to solve this problem and arrived at the present invention. That is, the gist of the present invention is that at least one of the left and right molds operates horizontally, vertically and independently, and the thermoplastic resin molten parison is moved between the left and right molds in which the length of the mold to be clamped later is shorter than the length of the mold to be clamped first. An L-shaped rod with an inner tank held at the tip of the horizontal rod is placed inside the mold from above or below, and when one of the upper or lower molds is closed, an attachment provided at the bent part of the L-shaped rod is inserted. A device is used to project a horizontal rod horizontally to press the inner tank to the inner wall surface of the parison, and then the L-shaped rod is taken out of the mold, the entire mold is clamped, and air is blown. This is a method for manufacturing a thermoplastic resin fuel tank.

The present invention will be explained below using the drawings.

FIG. 1a shows an example of the process of the present invention,
The thermoplastic resin molten parison 2 extruded or injected from the die 1 descends into the mold, the upper mold 3 is closed by the operating mechanism 9, and the parison 2 is placed at the tip of the horizontal rod 5a of the L-shaped rod 5. Installed inner tank 4
is the attached device 1 provided at the bent part of the L-shaped rod 5.
0 is horizontally projected and is pressed into a predetermined position on the inner surface of the parison 2. After that, the L-shaped rod 5 is taken out of the mold, the lower mold 7 is closed by the operating mechanism 8, and air is blown into the inner tank 4 by the air pin 6 that enters inside at the seam of the lower mold 7. A thermoplastic resin fuel tank is formed.

In this way, the attached device 10 is installed at the bent part of the L-shaped rod 5, and the horizontal rod 5a is made to protrude, and the inner tank 4 is moved horizontally and is attached to the inner surface of the parison 2 using the inner surface of the closed upper mold 3 as a support. Because it forces
A complicated inner tank as shown in Figure 1b can be correctly heat welded to the inner surface of the side of the parison.
Furthermore, since the lower mold 7 is open, the rod can be easily taken out of the parison 2 after welding, even though it is an L-shaped rod.

The protrusion force of the horizontal rod 5a is such that if the edge of the inner tank 4 comes into contact with the molten parison 2 with slight pressure, a large ejection force is not required. There are no mechanical limitations. For example, a mechanism can be adopted in which a horizontal rod 5a is fitted into the accessory device 10 to form a piston-like shape and the horizontal rod 5a is made to protrude by air.

Also, if the rod is inserted and removed from above, the length of the upper mold should be shorter than the lower mold, and if the rod is inserted and removed from the bottom, the length of the lower mold should be shorter than the upper mold. However, when pre-blowing, it is possible to prevent the parison on the rod side from swelling too much, which is preferable.

[Brief explanation of the drawing]

FIG. 1a is a longitudinal sectional view showing an example of the method of the present invention, and FIG. 1b is a perspective view showing an example of the inner tank. 1...Die, 2...Thermoplastic resin melting parison, 3...Upper mold, 4...Inner tank, 5
... L-shaped rod, 5a ... Horizontal rod, 6 ... Air blowing pin, 7 ... Lower mold, 8 ... Operating mechanism, 9
...Mold clamping mechanism of the molding machine, 10...Attached device.

Claims (1)

[Claims] 1 Between the left and right molds, at least one of which operates vertically and horizontally, and where the mold to be clamped later is shorter than the length of the mold to be clamped first, the upper part of the mold is placed inside the thermoplastic resin molten parison. Alternatively, insert an L-shaped rod holding the inner tank at the tip of the horizontal rod from below, close either the upper or lower mold, and use an attached device installed at the bent part of the L-shaped rod to level the horizontal rod. A thermoplastic resin fuel tank characterized in that after the inner tank is protruded and crimped onto the inner wall surface of the parison, the L-shaped rod is taken out of the mold, the entire mold is clamped, and air is blown. manufacturing method.