JPH0123797Y2 - - Google Patents

Description

[Detailed explanation of the invention] (Industrial application field) This invention heats and softens a sheet-shaped synthetic resin.
The present invention relates to a free blowing device that stretches a synthetic resin sheet into a hemispherical shape using compressed air to make the surface of a synthetic resin sheet uniform in thickness with a wrinkle-free mirror finish, and then adsorbs it into a mold to form it into a predetermined shape.

(Prior Art) Generally, in the above-mentioned free blowing molding apparatus, a mold for molding a synthetic resin sheet is fixed in a compressed air chamber for stretching the synthetic resin sheet into a hemispherical shape. is normal.

Therefore, when replacing the mold, it is necessary to disassemble and assemble part or all of the chamber, which is a very troublesome task.

(Purpose of the invention) The present invention was made with the aim of solving the above problems, and it is possible to carry out hemispherical stretching of a synthetic resin sheet and molding with a mold in the same way as before, and at the same time It is an object of the present invention to provide a free blowing molding device in which molds can be exchanged very easily.

(Structure of the invention) The structure of the invention will be explained in detail below with reference to an illustrated example. Reference numeral 1 is an elevating cylinder fixed upward to a frame (not shown), and a base 3 is fixed to the tip of a piston rod 2 of the cylinder 1. There is.

A mold surface plate 5 is removably attached to the upper part of the base 3 via a mounting frame 4 of a predetermined height. Positioning pin 7 that fits into the drilled positioning hole
has been planted.

Further, the base 3 is provided with a suction pipe 8 that penetrates the base 3 from below, reaches the mold surface plate 5, and opens its upper end on the upper surface of the mold surface plate 5. is connected to a vacuum pump (not shown) via an on-off valve 9.

Furthermore, cylinders 10, 10 are arranged horizontally opposite each other on both outer sides of the mold surface plate 5, hollow roller frames 12, 12 are fixed to the tips of the piston rods 11, 11, and the cylinders By the operation of 10, 10, the hollow roller frame 1
The interval between 2 and 12 is adjusted.
The hollow roller frames 12, 12 are arranged such that the mold 6 is locked on the rollers with the minimum interval, and a slight gap is left between the mold surface plate 5 at the lowest position and the mold 6. They are arranged in a positional relationship such that the mold 6 is in a state where it can be moved (see Fig. 1), and it is retreated to a position where it does not interfere with the lifting and lowering of the blow box 13 (described later) with the maximum interval (see Fig. 2). ing.

A plurality of upward cylinders 1 are provided at the periphery of the base 3.
4, 14 are arranged, and the cylinders 14, 1
The bottom portion of the blow box 13 is fixed to the tips of the piston rods 15, 15 of No. 4. The blow box 13 has a box shape large enough to accommodate the mold 6, and forms a bottom portion forming a flange portion 16 bent inward at 90 degrees at the lower end, and the flange portion 16 is raised. It protrudes to such a length that it locks onto the lower surface of the mold surface plate 5, and is disposed so as to pass through the mounting frame 4 vertically. Further, an air pipe 18 communicating with a compressed air source (not shown) is connected to the side of the blow box 13 via an on-off valve 17. The mold 6 is fixed on the hollow roller frames 12, 12 in the closed state, and the mold 6 has a suction hole 1 communicating with the molding surface from a position corresponding to the suction pipe 8.
9 is perforated.

Furthermore, a downward cylinder 20 is provided above the mold 6, and a molding assist 2 is connected to the tip of a piston rod 21 of the cylinder 20 via a mounting plate 22.
3 is attached corresponding to the molding surface of the mold 6.

At a position between the mold 6 and the molding assist 23,
From the bottom, the lower heater 24 and the seat holding frame 2
5 and the upper heater 26 are arranged at appropriate intervals and can be moved in and out by horizontal movement.

A roller conveyor (not shown) is installed behind the hollow roller frames 12, 12 to carry in and out the mold 6. Further, an annular seal (not shown) is embedded in the upper end periphery of the blow box 13 and the upper surface periphery of the flange portion 16. Further, numeral 27 in the figure is a synthetic resin sheet held by the sheet holding frame 25.

(Operation of the invention) In the device configured as described above, the cylinder 1 is operated in the state shown in FIG. The mold 6 is raised from the hollow roller frames 12, 12, and the cylinders 10, 10 are actuated to move the hollow roller frames 12, 12 so that the blow box 13 can rise without any hindrance. retreat to position.

On the other hand, electricity is supplied to the lower heater 24 and the upper heater 26 for a predetermined period of time, so that the synthetic resin sheet 27 held by the sheet holding frame 25 is heated and softened to the state shown in FIG. 2.

Next, after the lower heater 24 and the upper heater 26 are moved laterally, the cylinders 14, 14 are operated to bring the flange 16 of the blow box 13 into contact with the lower surface of the mold surface plate 5, and the cylinder 1 is further moved. The blow box 13 is operated to bring the upper end of the blow box 13 into contact with the lower surface of the sheet holding frame 25 (see FIG. 3) and is temporarily stopped. In this state, the upper and lower ends of the blow box 13 are held airtight.

In this state, the on-off valve 17 is opened to supply compressed air at a predetermined pressure into the blow box 13 for a predetermined time,
The synthetic resin sheet 27 is stretched into a hemispherical shape as shown in FIG. Due to this action, the synthetic resin sheet 27 is made into a mirror-like sheet with a uniform thickness and no wrinkles. In this state, the cylinder 1 is further operated to raise the mold 6 until it comes into contact with the sheet holding frame 25. At this time, the blow box 13 is
5 prevents cylinder 1 from rising.
The piston rods 15, 15 of 4, 14 are shortened. As a result, the airtightness between the lower surface of the mold surface plate 5 and the flange portion 16 of the blow box 13 is released.

Next, the on-off valve 9 is opened and the space surrounded by the molding surface of the mold 6 and the synthetic resin sheet 27 is sucked by a vacuum pump (not shown). At the same time, the cylinder 20 operates, and the molding assist 23 descends while assisting and deforming the synthetic resin sheet 27, and the mold 6
I will guide you inside. As a result, the synthetic resin sheet 27 is finally molded along the molding surface of the mold 6 under suction as shown in FIG.

Next, the cylinders 1, 14, and 20 operate in reverse to release the mold 6, blow box 13, and molding assist 2.
3 is returned to the position shown in FIG. 2, and the molded synthetic resin sheet 27 is left held in the sheet holding frame 25. Next, the sheet holding frame 25 is moved laterally and the formed sheet is removed.
The next new synthetic resin sheet 27 is attached.
Then, the upper and lower heaters 26, 24 and the sheet holding frame 25 are moved between the mold 6 and the molding assist 23, resulting in the state shown in FIG. 2, and the above operations are repeated.

In this example, the forming assist 23 is used for sheet forming.
However, if the mold shape is simple, the molding assist 23 may not be used.

(Effects of the invention) The present invention has a structure in which the mold can be moved in and out using a hollow roller frame with adjustable roller width intervals, and the mold can be hermetically stored and released by raising and lowering the blow box. This makes it possible to mold synthetic resin sheets in the same manner as before, and at the same time allows for extremely easy replacement of molds, making a significant contribution to this industry.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, and FIG. 1 is a cutaway front view of the main parts showing the state in which the mold is carried in, FIG. 2 is a front view of the same showing the state in which the mold is received, and FIG.
This figure is a front view showing the sheet in a stretched state, and FIG. 4 is a front view showing the sheet in a molded state. 3: Base, 5: Mold surface plate, 6: Mold, 8: Suction pipe, 12: Hollow roller frame, 13: Blow box, 18: Air pipe.

Claims (1)

[Scope of utility model registration request] A mold surface plate 5 is provided on the upper part of the base 3 which can be raised and lowered via a mounting frame 4, and a suction pipe 8 is provided in the base 3 to penetrate from the bottom to the top and reach the upper surface of the mold surface plate 5. On both sides slightly above the mold surface plate 5, hollow roller frames 12, 12 for receiving the mold 6, the interval of which can be adjusted, are arranged. Above, from the bottom, there are a lower heater 24 and a seat holding frame 2.
A box-shaped blow box 13 surrounding the mounting frame 4 is provided on the base 3 so as to be movable up and down.
The upper end opening of 3 is sized so that its upper end abuts the lower surface of the sheet holding frame 25 and can accommodate the mold 6 when it is raised, and its lower end is made to come into contact with the mold platen 5 when it is raised. 1. A free blowing molding apparatus characterized in that the flange part 16 is bent inwardly, and an air pipe 18 communicating with a compressed air source is arranged at the side part.