JPS6260973B2 - - Google Patents

Abstract

PURPOSE:To manufacture a boat-shaped container by a method wherein a boat- shaped developed sheet of thermoplastic resin foamed sheet is introduced on a female die having an inclined surface, a male die is dropped, said sheet is introduced into the female die and a heating edge is inserted between the raised and bent side end parts of the boat to weld said end part. CONSTITUTION:A boat-shaped developed sheet C of thermoplastic resin foamed sheet is supplied on female dies 10, 11 having inclined surfaces, and mounted on a lifting back plate 18 to be supported. Next, the male die 24 is dropped and presses the sheet C. This sheet C enters the insides of the female dies 10, 11 with the lifting back plate 18. The boat sides C1-C4 of the sheet C is raised and bent by inclined plates 6a, 7a. Further, the heating edge 29 is inserted between the ends of the boat sides C1-C4, and the ends are heated, melted and welded. In this manner, it is possible to obtain a boat-shaped container in which the ends are welded completely to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a boat-shaped container from a boat-shaped spread sheet made of a thermoplastic resin foam sheet.

Several methods and apparatus for manufacturing boat-shaped containers have been proposed in the past, but all of them have a drawback in the means for welding together the ends of the boat-shaped unfolded sheets that are raised and folded in a female mold. Therefore, it is difficult to manufacture a boat-shaped container with a high bonding strength at the fused portion, and especially in a boat-shaped container with a curved side surface, strong internal stress occurs on the curved side surface, making it difficult to use the container. Problems such as failure of the bond at the fused portion sometimes occur, and an improvement has been desired in order to obtain a boat-shaped container with good quality.

The present invention has been made in view of the above-mentioned points, and includes a method for manufacturing a boat-shaped container, in which the end portions of each boat side surface can be firmly fused to each other, and the bonding strength at the fused end portions can be increased. The purpose is to provide manufacturing equipment.

That is, one of the present inventions is to guide a boat-shaped unfolded sheet made of a thermoplastic resin foam sheet onto a female mold having an inclined surface, and place the sheet on an elevating receiving plate, so that the bottom of the boat-shaped sheet is approximately the same as the bottom of the sheet. A shaped male mold is lowered and the sheet is pushed down by the male mold to guide it into the female mold, each side of the sheet is bent up and a heating blade is inserted between the ends of each side of the sheet to A boat shape characterized by melting the ends and removing the heated blade, then lowering the male mold to further raise each boat side, and bringing the ends into contact with each other and fusing them. The gist is the method of manufacturing the container. Another aspect of the present invention is that a plurality of female molds arranged on a machine stand and provided with an inclined surface, and a boat-shaped unfolding sheet made of a thermoplastic resin foam sheet are placed, and an elevator that moves up and down inside each of the female molds. a plate, a male mold placed above the elevating receiving plate and pushing down the boat-shaped unfolded sheet, a lifting means for raising and lowering the male mold, and an end portion of each boat side surface of the sheet raised and bent in the female mold. The gist of the present invention is a boat-shaped container manufacturing device comprising: a heating blade which is inserted into the container so as to be movable forward and backward, and which heats and melts the end portion.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows an overall perspective view of the manufacturing apparatus according to the present invention, and FIGS. 2A to 2F show each step of the manufacturing method according to the invention using this apparatus.

In the figure, reference numeral 1 denotes a table-like machine base, and above this a flat plate-like frame 2 is supported by pillars 3. Four female molds 8 to 11 are arranged approximately in the center of the machine base 1 so that the inner shape thereof is boat-shaped.
The method of attaching the female molds 8 to 11 to the machine base 1 is not particularly limited, but for example, the female molds 8 to 11 may be attached so as to be movable laterally so that the size of the boat formed inside can be changed within a certain range. (For example, as shown in FIG. 3, it is attached movably in the direction of the arrow). Female molds 8-11 have female mold bases 4-7,
Slanted plates 4a to 7a forming inclined surfaces on the inner surfaces of the female mold bases 4 to 7 are provided on the upper side of the inner sides of the female mold bases 4 to 7, respectively. As will be described later, these inclined plates 4a to 7a are arranged on each side of a boat-shaped unfolded sheet C made of a thermoplastic resin foam sheet, for example, as shown in FIG.
It acts to raise _C1 to _C4 . The female molds 8 to 11 consisting of the female mold base and the inclined plate are made of metal, for example. Examples of the material metal for the female mold include aluminum, phosphor bronze, copper, and iron, and among them, aluminum is preferred.

As shown in FIG. 3, a slight gap δ is provided at the corner portions of the female molds 8 to 11 that are close to each other.

One side of each of the female molds 8 to 11 arranged as described above, that is, the supply side of the boat-shaped development sheet C (arrow x
There is a positioning plate 12 for the sheet C on the side opposite to the
is installed. The positioning plate 12 is slidably supported by a support rod 14 attached above a mounting bracket 13 fixed to the machine base 1, and is always supported by a coil spring 15 to the left in FIG. 2A. The machine moves backward while receiving the supplied sheet C at the front end 12a, and when the rear end 12b comes into contact with the contact point of the setting switch 17 attached to the mounting bracket 16 also fixed to the machine base 1. , the seat C is positioned at a desired position.

Inside each of the female molds 8 to 11, an elevating receiving plate 18 for receiving the bottom surface _C5 of the boat-shaped unfolded sheet C shown in FIG. 5 is provided so as to be movable up and down. In the case of this embodiment, for example, a rod-shaped guide column 19 is fixed to the bottom surface of the receiving plate 18, and this column 19 is guided to the machine base 1, and a coil spring 20 for compression is attached to this column 19, so that the column is always It is elastically biased upward.

Below this lifting plate 18 is a hydraulic cylinder,
Rod 22 of cylinder 21 such as air cylinder
A stopper 23 for a receiving plate connected to the plate is arranged so as to be movable up and down. On the other hand, above the receiving plate 18, a flat male die 24 having a shape substantially the same as the bottom surface _C5 of the boat-shaped unfolded sheet C is opposed. This male mold 24 is connected to a rod 26 of a cylinder 25 such as a hydraulic cylinder or an air cylinder for raising and lowering the male mold attached to the frame 2. Preferably, a guide rod 27 that is guided by the frame 2 is fixed to the upper surface of the male mold 24 so that a high accuracy of raising and lowering can be maintained when the cylinder 25 moves up and down. The male die 24 may be made of any material as long as it has the strength to press the bottom surface _C5 of the sheet C and is not easily deformed; for example, iron, aluminum, copper, or even wood can be used.

In addition, at the four corners of the machine base 1, each female mold 8 to 11
A heating blade 29 attached to a mounting bracket 28 fixed to the machine base 1 is installed at a position corresponding to the gap δ between the two. This heating blade 29 is for heating and welding the adjacent ends of the upright and bent boat sides C ₁ to C ₄ of the boat-shaped unfolded sheet C, that is, the corner portions. It is connected to a rod 31 of a cylinder 30 such as a cylinder. The mounting bracket 2 is designed to maintain high precision when moving forward and backward using this cylinder 30.
It is preferable to provide a guide rod 32 guided by 8. The heating part 29a of the heating blade 29 is designed so that the temperature of the cutting edge can be set arbitrarily, for example, 400~
It is also possible to set the temperature to 600°C.

In addition, 33 is a cooling nozzle that blows out a cooling medium to cool down the fused portion of the sheet C by the heating blade 29, and 34 is a container removal nozzle that blows out compressed air to remove the boat-shaped container from the apparatus after molding is completed. It's a nozzle.

Next, an example of a method for manufacturing a boat-shaped container using the apparatus configured as described above will be described.

First, as shown in FIG. 2A, a boat-shaped unfolded sheet C (FIG. 5) made of a thermoplastic resin foam sheet is supplied from the arrow x direction onto each of the female molds 8 to 11 placed approximately in the center of the machine base 1. do. Then, the front end of the sheet C hits the front end 12a of the positioning plate 12, and after the positioning plate 12 is moved back slightly, the rear end 12b of the positioning plate 12 comes into contact with the setting switch 17, and the desired position is reached. The bottom surface _C5 of the seat C is placed and supported on the elevating receiving plate 18.

Next, as shown in FIG. 2B, the male mold 24 is lowered by the drive of the cylinder 25, and the bottom of the sheet C
Press C ₅ . As a result, the bottom surface _C5 of sheet C
enters inside each of the female molds 8 to 11 together with the lower elevating receiving plate 18. Along with this, each of the boat side surfaces _C1 to _C4 of the sheet C gradually rises and is bent while contacting the inclined plates 4a to 7a. When a predetermined lowering position is reached, the lifting receiving plate 18 comes into contact with the stopper 23, as shown in FIG. 2C, and the lowering movement is stopped.

By the above operation, each side of the boat C ₁ to _{C 4} of the seat C
are bent up to a predetermined angle, and a gap necessary for inserting the heating blade 29 is formed between the ends of each of the boat side surfaces C ₁ to C ₄ . Next, as shown in FIG. 2D, the cylinder 30 is driven, the heating blade 29 moves forward, and is inserted into the gap between the ends, heating and melting the ends instantly (for example, in 0.1 to 0.2 seconds). , retreat. At this time, the heating blade 29
Although it may be in direct contact with the above-mentioned end portion, it may also be made to be slightly spaced apart and melted by radiant heat.

After the above-mentioned melting, as shown in FIG. 2E, the stopper 23 is lowered by the cylinder 21, and the male mold 24 is further lowered by the cylinder 25.
As a result, each of the boat sides C ₁ to C ₄ further rises, so that their ends strongly abut each other, and as a result, the ends are reliably fused to each other, and the bonding strength thereof becomes extremely strong.

In addition, the temperature of the cutting edge of the heating blade 29 is, for example, 400 to 600°C.
When the temperature is set to an extremely high temperature, the resin melts quickly, making it possible to perform the above-mentioned fusion in a short time, and the resin adhering to the blade decomposes at high temperatures, making it difficult to remove the adhering resin (molten residue). This has the advantage that it is simple or unnecessary.

Next, a cooling medium such as cold air is blown onto the fused portion from the cooling nozzle 33 so that the resin hardens more quickly, thereby cooling the fused portion.

Finally, as shown in Figure 2F, the cylinder 25
By raising the male die 24 and blowing compressed air or the like from the detachment nozzle 34, a boat-shaped container B as a completed product as shown in FIG. 6 is obtained.

There are various types of thermoplastic resin foam sheets used in the present invention, among which:
Particularly preferred are foamed sheets of polystyrene-based resins such as polystyrene homopolymer, styrene-maleic anhydride copolymer, and high-impact polystyrene made by blending polystyrene with polybutadiene or the like.

In the above embodiment, an inclined plate was provided on the female base, and this inclined plate formed an inclined surface.
The inclined surface may be formed directly on the inner surface of the female mold without providing the inclined plate.

As explained above, the method of the present invention involves pushing down a boat-shaped unfolded sheet using a male mold and introducing it into a female mold, bending each boat side surface of the sheet upright, and inserting a heating blade between the ends of each boat side surface. After melting the ends and removing the heated blade, the male mold is lowered to further raise each side of the boat, and the ends are brought into contact with each other and fused together. , and since the device of the present invention has a configuration for this purpose, the ends can be brought into strong contact with each other, and as a result, the ends can be reliably fused to each other, and the connection at the fused portion of the ends can be The strength can be extremely increased. One possible method for bringing the ends into contact with each other is to move the female molds slightly toward each other, and use the movement of the female molds to push each side of the boat in the upright direction. With this method, it is difficult to control the distance the female mold moves; for example, if the distance traveled is too large, the side of the boat will be pushed too hard, and the rising angle of the side of the boat will become close to vertical, resulting in a shape that is different from the desired shape. On the other hand, if the moving distance is too small, the side surface of the boat cannot be pushed sufficiently, and there is a risk of defective fusion between the ends. In contrast, in the present invention, the male mold is lowered to raise the side of the boat, and this rising action brings the ends into contact with each other, so no direct force is applied to each side of the boat, and Therefore, the ends can be brought into proper contact with each other, and there will be no problem of the rising angle of the boat side being too large or too small.

[Brief explanation of the drawing]

The drawings show an embodiment of the method and manufacturing apparatus of the present invention, and FIG. 1 is an overall perspective view showing the manufacturing apparatus of the present invention, and FIGS. 2A to 2F are process explanatory diagrams showing each step of the manufacturing method of the present invention. FIG. 3 is a schematic plan view showing the arrangement of the female molds in the manufacturing apparatus shown in FIG. 1, and FIG.
5 is a plan view showing the boat-shaped unfolded sheet, and FIG. 6 is a perspective view showing the boat-shaped container. 1...Machine base, 8-11-female type, 18...elevating receiving plate, 24...male type, 25...male type elevating cylinder, 29...heating blade, C...boat-shaped unfolding sheet,
C ₁ to _{C 4} ... side of the boat.

Claims (1)

[Scope of Claims] 1. A boat-shaped unfolded sheet made of a thermoplastic resin foam sheet is guided onto a female mold having an inclined surface, and the sheet is placed on an elevating receiving plate, and the shape is approximately the same as the boat-shaped bottom of the sheet. The male mold is lowered and the sheet is pushed down by the male mold to guide it into the female mold, each side of the sheet is bent upright, and a heating blade is inserted between the ends of each side of the sheet to separate the ends. After melting the parts and removing the heating blade, the male mold is further lowered to further raise each side of the boat, and their ends are brought into contact with each other and fused together. manufacturing method. 2. A plurality of female molds arranged on a machine stand and equipped with an inclined surface, an elevating catch plate on which a boat-shaped unfolding sheet made of a thermoplastic resin foam sheet is placed, and which moves up and down within each of the female molds, and the elevating catch plate. A male die installed above to push down the boat-shaped unfolding sheet; a lifting means for raising and lowering the male die; A boat-shaped container manufacturing device characterized by comprising a heating blade that heats and melts the end portion.