JPH05200841A - Blow molding method and apparatus - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a blow molding method and device, and more particularly, when a parison is deformed, the deformable assembly provided in the parison is easily deformed and restored after the deformation. Is ensured and rapid molding is performed. According to the blow molding method and apparatus of the present invention, a plurality of piece members (2, 4, 6, ...) Arranged in parallel with each other through a plurality of elastic bodies are connected to wires (8a, 8b) having different lengths. (...)
A deformable assembly (A) in which the connection state of each piece member (2, 4, 6) is freely deformable through the wires (8a, 8b ...) After that, the shape of the deformable assembly (A) is bent to preform the parison (20) into a predetermined shape, and after the mold is closed, the parison (20) is placed in the parison (20). Molded product by supplying pressurized fluid
(B) is molded, the wire members (8a, 8b ...) Are loosened, and the deformable assembly is removed from the molded product (B).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow molding method and apparatus, and more particularly, when a parison is deformed, the deformable assembly provided in the parison is easily deformed and restored after the deformation. It relates to a new improvement for ensuring and rapid molding.

[0002]

2. Description of the Related Art Generally, for molding a hollow container,
Although the blow molding method is applied, among the blow molded products, there are some in which the axis of the hollow portion is bent two-dimensionally or three-dimensionally. In order to manufacture such a molded product, it is usually necessary to bend and accommodate a hollow parison along one mold in one mold of a mold divided into two. As an example, in Japanese Patent Laid-Open No. 63-280613, a parison is extruded from an extrusion die head between the die while the die is open, and at a low temperature below the martensite transformation end temperature from the extrusion die head. A shape memory alloy having elasticity that becomes a straight shape is drooped and fed into the parison, and the drooping fed shape memory alloy is heated to a temperature higher than the reverse transformation end temperature by the heat of the parison, and the martensite transformation start temperature is preset. The parison is preformed into a mold cavity shape by this deformed shape memory alloy, and then the mold is combined and blow molded into a predetermined shape, during or after this molding. Discloses a method in which the shape memory alloy is withdrawn from the inside of the cavity of the mold before and after it changes into a rod shape. . This makes it possible to manufacture a molded product in which the axis of the hollow portion is bent in two dimensions or three dimensions.

[0003]

Since the conventional blow molding method is constructed as described above, there are the following problems. That is, the blow molding method using a shape memory alloy has a problem that it may be difficult to pull out the shape memory alloy from a bent molded product. For example, in the case of a molded product that is bent in a U-shape, the shape memory alloy is also deformed in a U-shape at a temperature equal to or higher than the reverse transformation end temperature. If the space is not very large,
It is difficult to extract a shape memory alloy from a molded product. Moreover, at low temperatures below the martensitic transformation end temperature, the shape memory alloy has a straight shape, so during drawing,
It may also damage the molded product. Therefore, the molded products that can be produced by the above-mentioned conventional method are limited to S-shaped products that are almost straight lines and simple two-dimensional or three-dimensional bent shapes. Further, the deformation response speed of the shape memory alloy with respect to temperature is extremely slow, which is not satisfactory for such applications, and it has been impossible to improve the effect of producing a molded product.

The present invention has been made to solve the above problems, and in particular, when the parison is deformed, the deformable assembly provided in the parison is easily deformed and deformed. It is an object of the present invention to provide a blow molding method and apparatus that ensures a later restoration and performs rapid molding.

[0005]

In the blow molding method according to the present invention, a plurality of piece members arranged in series with each other via a plurality of elastic bodies are connected by a plurality of wires having different lengths, and the plurality of piece members are connected via the wires. A deformable assembly in which the connection state of each piece member is freely deformable is placed in a parison, and then the shape of the deformable assembly is bent to preform the parison into a predetermined shape, After closing the mold, a pressurized fluid is supplied into the parison to form a molded product, and the wire member is loosened to remove the deformable assembly from the molded product.

A blow molding apparatus according to the present invention is a blow molding apparatus having a head member for pushing out a parison and a mold which is arranged below the head member and which can be opened and closed.
A deformable assembly composed of a plurality of piece members, which is connected and disposed below the head member via a plurality of wires, an elastic body provided between the piece members, and an elastic body provided above the head member. A plurality of wire driving bodies for moving the wire up and down are provided, and each piece member is biased by the elastic body in a direction in which they are separated from each other.

More specifically, the wire passes through the piece members, and any one of the piece members is
In this configuration, the inclined bottom surface is molded.

[0008]

In the blow molding method and apparatus according to the present invention, first, the deformable assembly is linearly positioned with the wires loosened, and is positioned vertically in the molten parison. After that, by pulling each wire of different length upward, each piece member connected to the lower end of each wire joins and bends against each other against the force of the elastic body to change the posture of each piece member, The parison is preformed along this shape because it has a predetermined two-dimensional or three-dimensional bent shape. The preformed parison is placed in the cavity together with the deformable assembly to close the die.
After that, by blowing a pressurized fluid (air) into the parison, the parison is pressed against the inner surface of the cavity,
It becomes a blow molded product with a predetermined shape. Next, when each wire is loosened in order and each piece member is placed in a deformable release state, the piece members are separated from each other by the action of the elastic body, and after the blowing is completed, the deformable assembly is extracted from the molded product. By opening the mold and taking out the molded product from the mold, it is possible to manufacture a molded product in which the axis of the hollow portion is two-dimensionally or three-dimensionally bent with high efficiency. Therefore, each piece member is separated by the biasing of the elastic body through each elastic body member,
The piece members are reliably separated from each other when straight and bent, and the separation from the parison is extremely smooth.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a blow molding method and apparatus according to the present invention will be described in detail below with reference to the drawings. 1 to 10 show a blow molding method and apparatus according to the present invention. FIG. 1 is a sectional view of the overall structure, FIG. 2 is a perspective view of a piece member, and FIG. 3 is a structure showing a bent state of the piece member. FIGS. 4 and 5 are configuration diagrams showing the operation, FIGS. 6, 7 and 8 are sectional views showing the operation, and FIGS. 9 and 10 are configuration diagrams showing the wire driving body.

First, the sleeve 12 is fixed in the center hole of the head portion 22 for pushing out the parison 20 of the hollow molding machine 50, and a plurality of wires 8a, 8b are hung at the lower position of the sleeve 12 to suspend the parison 20. The deformable assembly A in the closed state is arranged. This deformable assembly A is shown in FIG.
As shown in FIG.
And a plurality of wires 8a and 8b penetrating each piece member 2, 4 and 6, and a spring 60 which is an elastic body provided between each piece member 2, 4 and 6. Also,
As shown in FIGS. 4 and 5, the springs 60 are held and positioned in the recesses 61 formed on the facing surfaces of the piece members 2, 4 and 6, respectively. The piece members 2, 4, 6 are always urged in a direction in which they are separated via a gap t.

Each of the piece members 2, 4, 6 is made of a material having a property of being hard to adhere to another resin such as ethylene tetrafluoride resin, and each of the piece members 2, 4, 6 has a length. Are connected to different wires 8a and 8b. The sleeve 12 has a cylindrical shape with an outer diameter smaller than the inner diameter of the parison 20, and the lower half of the sleeve 12 is formed with an inner diameter larger than the outer diameter of the deformable assembly A. The through hole 12a provided over the other half of the length is formed to have an inner diameter that does not hinder the movement of the wires 8a and 8b of the deformable assembly A, and is an air for blowing a pressurized fluid (not shown). It communicates with the blowing device.

A hollow portion 24 is provided above the head portion 22.
A movable member 24 having a is disposed, and an injection device (not shown) is connected to the head portion 22 and
As described above, the cylindrical parison 20 having a larger diameter than the outer diameter of the sleeve 12 can be extruded.

A hollow portion 24a of the movable member 24 is configured to accommodate a part of the sleeve 12, and the movable member 24 has eight guides (only two are shown in the drawing). The roll 14 is rotatably supported, and the wire 8
a, 8b ... Wire drive members 16a to 16h (disclosed in FIGS. 9 and 10), which are composed of eight fluid pressure cylinders for driving, are attached.

The wires 8a, 8b, ... Are attached to the rods of the wire driving bodies 16a to 16h through the through holes 12a of the sleeve 12 and the guide rolls 14, respectively. 16h can move the wires 8a, 8b, ... Up and down.

A plurality of driving bodies 18 composed of fluid pressure cylinders are attached to both side surfaces of the head portion 22, and rods 18a of each driving body 18 are connected to the movable member 24. The driving member 18 is capable of moving the movable member 24 in the vertical direction in the figure, and a mold 26 is disposed below the head portion 22 and the mold 2 is provided.
6 is configured to be opened and closed in the left-right direction by a pair of mold opening / closing cylinders 28.

Next, FIGS. 2 and 3 show a part of the deformable assembly A in a simplified manner. The piece members 2, 4 and 6 formed in a substantially cylindrical shape have an axis center. A plurality of through holes 2a, 4a, 6a are provided in parallel with each other.

Wires 8a, 8b ... Are pierced through the through holes 2a, 4a and 6a of the piece members 2, 4 and 6, respectively. In this case, eight wires (only two wires are shown) 8 are provided.
The lengths of a, 8b, ... Are sequentially different, and are connected to the piece members 2, 4, 6 through the stopper 10. Therefore, the wires 8a, 8b ...
Although only two lengths are shown in this embodiment, eight wire drivers 16a to 16 are provided as shown in FIGS.
The lengths of the wires 8a, 8b, ... Connected to h are sequentially different, and the wires 8a, 8b ,. 9 and 10) are individually connected.

Each of the piece members 2, 4, 6, ... Usually consists of eight parts, but here, the structure is shown for three of them, as shown in FIGS.
A rectangular convex portion 2c is provided at an end of the piece member 2 adjacent to the intermediate piece member 4, and the intermediate piece member 4 has the convex portion 2c at one end on the lower side. A groove portion 4c to be fitted is provided, and a half-moon key-shaped convex portion 4d is provided at the other end portion on the upper side thereof. The uppermost piece member 6 is provided at its lower end adjacent to the piece member 4 with a groove portion 6c to be fitted with the convex portion 4d.

The bottom of the piece member 6 is provided with a slanted bottom surface 6d which is obliquely cut out, and the slanted bottom surface 6d is arranged at a related position through which the through hole 6a passes. A rectangular convex portion 6e is provided at the upper end of the upper piece member 6, and the convex portions 2c, 4d and 6e and the groove portions 4c and 6c are all penetrated by the axial center in the longitudinal direction. The holes 2a, 4a, 6a are provided so as to be orthogonal to the axes thereof. In addition, in FIG. 2, three piece members 2,
Although only 4 and 6 are shown, actually, as shown in FIGS. 1, 9 and 10, eight piece members are adopted.

Therefore, by using the piece members 2, 4, 6 ... Connected by the eight wires 8a, 8b ..
.. are freely deformed, as shown in FIG. 13, when the wires 8a, 8b ...
4 and 6 are linear, but each wire driving body 16a
.. through 16h, the piece members 2, 4, 6 ...
Since the wires 8a, 8b, ... Are pulled from 0 as the starting point, the lower inclined bottom surface 6d of the upper piece member 6 in the middle is compressed in the state where each spring 60 is compressed, as shown in FIGS. By contacting the upper surface of the piece member 4, the deformable assembly A can be bent into a predetermined shape. In this case, the fitting portions such as the convex portion 2c and the groove portion 4c described above prevent misalignment between the piece members 2, 4, 6 and guide the bending direction. That is, parison 20
By making such a bend in the parison 20
Can be preformed into a predetermined shape, and by arbitrarily selecting the piece members 2, 4, 6, ... Connecting the wires 8a, 8b .. The bent shape can be obtained.

Next, the operation of the first embodiment of the present invention will be described. In advance, the drive member 18 is driven to bring the movable member 24 into close contact with the head portion 22, the die opening / closing cylinder 28 is driven, and the die 26 is opened.
6H is driven and the deformable assembly A is hung substantially linearly with the spring 60 extended. Molten resin is supplied from an injection device (not shown) to hang the parison 20 in a cylindrical shape on the outer diameter portion of the deformable assembly A (FIG. 1).

Next, the deformable assembly A is actuated by actuating the wire driving bodies 16a to 16h to pull up the wires 8a, 8b, ... (Shown in FIG. 6), the parison 20 is preformed into a bent shape as shown in FIG. At this time, since each of the piece members 2, 4, 6, ... Is made of a material that does not easily adhere to another resin such as an ethylene tetrafluoride resin, it contacts the inner surface of the parison 20. However, it does not adhere.

Next, the mold opening / closing cylinder 28 is driven to close the mold 26, the parison 20 is placed in the cavity 30 together with the deformable assembly A, and air is supplied from an air blowing device (not shown) to make it hollow. A shaped product B is formed (FIG. 7).

Next, the die opening / closing cylinder 28 is driven to open the die 26, while the wire drivers 16a to 16h are driven to loosen the wires 8a, 8b ... , 6 ... are urged in the directions in which they are separated from each other by the action of the spring 60, and make the deformable assembly A in a freely deformable state (straight), and drive the drive body 18 to move the movable members. When the member 24 is moved upward as shown in FIG. 8, the deformable assembly A is smoothly accommodated in the sleeve 12. As a result, the molded product B can be dropped downward in the figure (FIG. 8). In addition, when the deformable assembly A bent as shown in FIG.
By loosening a, 8b ..., a gap t is formed between the piece members 2, 4, 6, ... By the action of the spring 60, so that each piece member 2, 4, 6 ,. It becomes a shape and is very easy to remove.

By repeating the above-mentioned steps, the shaft center becomes 2
It is possible to continuously manufacture a hollow molded article B that is bent in a dimension. In the above description, the inclined bottom surface 6d is 1
The bending is two-dimensional because it is provided only at the location, but the bending can be three-dimensional by combining a plurality of inclined bottom surfaces having different inclined surfaces. it can.

Further, the number of wires 8a, 8b, ... Is 8 or more so that a more complicated three-dimensional bent shape can be formed, and each of the wire driving bodies 16a-1.
6h is displaced 90 degrees from the mounting position of FIG. 1 so that the rods face downward, and the cylinder axis is set to the wires 8a, 8
The guide roller 14 can be omitted if it is attached so as to match the axis of b.

Further, although fluid pressure cylinders are used as the wire driving bodies 16a to 16h for driving the wires 8a, 8b ..., For example, a winch type winding device can be adopted, and similarly, the driving body 18 is used. Can be replaced by a linear drive device such as a linear motor.

Although the deformable assembly A descends first and waits for the parison 20 to descend in the above-described embodiment, the parison 20 and the deformable assembly A descend in the opposite manner. It is possible to do so, or to descend at the same time. Further, in this embodiment, the spring is used as the elastic body, but rubber or the like may be used.

[0029]

Since the blow molding method and apparatus according to the present invention are configured as described above, the following effects can be obtained. That is, a two-dimensional or three-dimensional bent shape can be arbitrarily created by individually pulling each piece member of the deformable assembly arranged in the parison with a plurality of wires having different lengths. It is possible to manufacture a hollow molded product in which the axis of the hollow portion is intricately twisted, and there is no fear of damaging the inside when the completed molded product is taken out. Further, since the elastic body is interposed between the piece members, when the wire is loosened, a gap t is formed between the piece members, so that the piece can be straightened or bent. The members are forcibly separated from each other, and the separation from the parison becomes extremely easy. In addition, even when the wire is tightened to make each piece member straight and bent, the elastic member acts to forcibly hold the shape of each piece member, so that there is no collapse of the shape. The shape of the parison to be molded can also be molded into a predetermined shape with high accuracy.

[Brief description of drawings]

FIG. 1 is a sectional view showing a blow molding apparatus according to the present invention.

FIG. 2 is an enlarged exploded perspective view showing a main part of FIG.

FIG. 3 is a configuration diagram showing an operation of a main part of FIG.

FIG. 4 is a configuration diagram in which each piece member is linear.

FIG. 5 is a configuration diagram in which each piece member is tightened into a bent shape.

FIG. 6 is a cross-sectional view showing an operating state of FIG.

FIG. 7 is a cross-sectional view showing an operating state of FIG.

FIG. 8 is a cross-sectional view showing an operating state of FIG.

9 is a configuration diagram showing a combined state of the main parts of FIG. 1. FIG.

10 is a configuration diagram showing a combined state of the main parts of FIG. 1. FIG.

[Explanation of symbols]

 2 piece member 4 piece member 6 piece member 6d inclined bottom surface A deformable assembly B molded product 8a wire 8b wire 16a wire driver 16h wire driver 20 parison 22 head member 26 mold 30 cavity 60 elastic body

Claims (3)

[Claims] 1. A plurality of piece members (2, 4, 6, ...) Arranged in series through a plurality of elastic bodies are connected by a plurality of wires (8a, 8b ...) With different lengths, The wires (8a, 8b ...
), The deformable assembly (A) in which the connection state of each piece member (2, 4, 6) is deformable is positioned in the parison (20), and then the deformable assembly. The parison (20) is preformed into a predetermined shape by bending the shape of the solid (A), and after the mold is closed, a pressurized fluid is supplied into the parison (20) to form a molded product (B). Is molded, the wires (8a, 8b ...) Are loosened, and the deformable assembly (A) is removed from the molded product (B). 2. A head member (22) for extruding a parison (20).
And a blow molding device having a mold (26) arranged below the head member (22) and capable of opening and closing, a plurality of wires (8a, 8b ...) Below the head member (22). Provided between the deformable assembly (A) composed of a plurality of piece members (2,4,6 ...) Connected via the respective piece members (2,4,6 ...) Each elastic member and a plurality of wire driving bodies (16a to 16h) provided above the head member (22) for moving the wires (8a, 8b ...) Up and down. (2,4,6
...) is configured to be urged in a direction in which the elastic bodies separate from each other. 3. The wires (8a, 8b ...) Are the piece members.
(2,4,6 ...) is penetrated, and an inclined bottom surface (6d) is formed on any of the piece members (2,4,6 ...). The blow molding apparatus according to claim 2.