JP2569745Y2 - Parison flexing equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parison bending device.

[0002]

2. Description of the Related Art As a conventional blow molding apparatus, there is one as shown in FIG. In the blow molding apparatus shown in this figure, a part of a mold 50 is divided to form a partial mold 52. The partial mold 52 is swingable about a shaft 54 as a swing center. The parison is positioned between the opened molds, and the mold is closed while the partial mold 52 is located at the mold partially open position indicated by the imaginary line. That is,
The mold is in a partially closed state in which only the 52 partial molds are opened. Next, the fluid pressure cylinder 56 is operated to swing the partial mold 52 connected to the piston rod toward the mold fully closed position shown by the solid line, so that the lower end side of the parison has an “L” shape. After being bent, the mold is completely closed. Next, by blowing a compressed fluid into the parison in the mold, a hollow container corresponding to the cavity shape, that is, a tank 58 having a bent portion shown by a broken line can be blow-molded.

[0003]

However, in the conventional blow molding apparatus as described above, the strength of the lower end of the molded product may be insufficient, or the surface of the lower end of the molded product may be roughened. There is a problem that there is. It is considered that this is because the mold 50 and the partial mold 52 constituting the cavity are not uniformly cooled. Normally, a cooling medium passage (not shown) is formed in the mold, and the mold is cooled by flowing a cooling medium through the cooling medium passage. Since it is thinner than the portion, it is difficult to provide a cooling medium passage in terms of strength, and it is not usually cooled. For this reason, the portion of the parison which is to be a molded product, in contact with the partial mold 52, has a lower cooling rate than the other portions, and the residual strain due to a temperature difference between an adjacent portion (a portion having a relatively high cooling speed). , The strength is insufficient or the surface is roughened. As a solution to this, it is conceivable to arrange the cavity in a state of being inclined with respect to the mold and to mold the parison without bending it.However, in the case of a hollow container having a screw at the mouth, Since the threaded portion is also inclined, and it is difficult to form a molded product in which the threaded portion axis is inclined with respect to the parison axis, the shape of the molded product is limited. The present invention aims to solve such a problem.

[0004]

According to the present invention, the parison is arranged between the molds opened in the horizontal direction, and then the parison is gripped by the lower end of the parison and moved to a predetermined bending position. The above-mentioned problem is solved by bending in accordance with the cavity shape. That is, the parison bending device of the present invention has the vertical parison (48) positioned between the horizontally opened molds (12, 14) and has a predetermined shape substantially matching the contour shape of the cavity (C). The parison pinch device (44) disposed below the position where the molds (12, 14) are disposed, and a pinch device moving device (46). The parison pinch device (44) is capable of moving the fixed pinch plate (32), the movable pinch plate (30), and the direction in which the movable pinch plate (30) approaches and away from the fixed pinch plate (32). The second actuator (2
8) and a pinch device moving device (46).
Has a first actuator (24) which drives the parison pinch device (44) to move between a standby position near the center of the lower part of the mold and a bending position above the lower end of the mold. It is characterized by doing. The parison pinch device (44) has a second bracket (26) to which a fixed pinch plate (32) is fixed, and a second actuator (28) is fixed to the movable bracket (26). A pinch plate (30) fixed to the second bracket (26) so as to face the fixed pinch plate (32);
The pinch device moving device (46) includes a first bracket (2
2), and the first actuator (24)
The first bracket (22) is fixed to the first bracket (22) such that the axis of the first actuator (24) can be angle-adjusted so as to form a predetermined inclination angle with respect to a horizontal plane.
The second bracket (26) of the parison pinch device (44) is attached to the first actuator (2).
It may be connected to the piston rod of 4). Further, the first actuator (2) of the first bracket (22)
4) a first bush (40) fixed to both sides of the position where the first actuator (24) is attached in parallel with the axis of the first actuator (24), and a first actuator (24) of the second bracket (26). On both sides of the position where the piston rod is mounted, there are first guide bars (38) fixed to the axis of the first actuator (24) and parallel to each other, respectively.
Is preferably fitted to the corresponding first bush (40) so as to be movable in the axial direction. Also, the second
The second actuator (2) is provided on both sides of the bracket (26) at the position where the second actuator (28) is attached.
8) a second bush (36) fixed parallel to the axis and a second actuator (28) on both sides of a position where the piston rod of the second actuator (28) of the movable pinch plate (30) is attached. 28) second guide bars (34) fixed respectively in parallel with the axis of (28).
The second guide bar (34) may be fitted to the corresponding second bush (36) so as to be movable in the axial direction, respectively. In addition, the code | symbol in a parenthesis shows the corresponding member of an Example.

[0005]

The parison is placed between the opened molds, and the lower end is gripped by a parison pinch device.
It is moved to a predetermined position outside the mold. As a result, the parison is bent into a shape along the cavity shape. Next, blow molding is performed according to a normal procedure. This makes it possible to blow-mold a hollow molded product having a bent shape without using a special divided mold.

[0006]

FIG. 1 shows an embodiment of the present invention. The accumulator head 10 of the blow molding machine is arranged at the upper part in the figure. The accumulator head 10 is connected to an extruder (not shown), and can accumulate molten resin supplied from the extruder and inject it as a parison 48 from the ring-shaped passage 10a. A parison aperture device 11 is disposed below the accumulator head 10.
The parison diaphragm device 11 has two movable diaphragm members 11a that are arranged opposite to each other in the figure, and the parison 48 that has begun to be ejected from the accumulator head 10.
May be narrowed to form a funnel-shaped parison 48a. The two aperture members 11a are respectively moved outward (in the retracted position direction) indicated by phantom arrows so as not to prevent the funnel-shaped parison 48a from hanging down immediately after performing the aperture operation. The dies 12 and 14 are arranged below the parison drawing device 11. FIG. 1 shows a state in which both molds 12 and 14 are closed (mold closed). A cavity C is formed by the two dies 12 and 14. In the case of this embodiment, the cavity C is bent substantially in a boot shape, and has a shape in which a screw portion is formed by narrowing the upper portion. A gantry 16 is fixed to a base portion below the dies 12 and 14. A support base (fixed portion) 18 is fixed to the gantry 16. A first bracket 22 is attached to the support base 18 via an angle adjustment bracket 20.
Are fixed obliquely so as to form a predetermined angle of inclination with respect to. A hydraulic cylinder 24 is attached to the first bracket 22. By adjusting the angle adjustment bracket 20, the angle between the horizontal plane of the gantry 16 and the axis of the hydraulic cylinder 24 can be adjusted. A second bracket 26 is fixed to the piston rod of the hydraulic cylinder 24.
An air cylinder 28 is attached to the second bracket 26. The air cylinder 28 is moved in the second direction so that a horizontal plane including its axis is parallel to the horizontal plane of the gantry 16.
It is attached to a bracket 26. Air cylinder 2
The movable pinch plate 30 is fixed to the piston rod 8. A fixed pinch plate 32 is fixed to the second bracket 26 so as to face the movable pinch plate 30. Second
Bracket 26, air cylinder 28, movable pinch plate 3
The parison pinch device 44 is constituted by the zero and the fixed pinch plate 32. By operating the air cylinder 28, it is possible to move the movable pinch plate 30 between a pinch release position separated from the fixed pinch plate 32 and a pinch position pressed against the fixed pinch plate 32. The pinch plates 30 and 32 can pinch the lower end of the funnel-shaped parison 48a at the pinch position as described later. With the hydraulic cylinder 24 etc.
A pinch device moving device 46 is configured. The pinch device moving device 46 moves the parison pinch device 44 between a standby position indicated by a solid line and a bending position indicated by a virtual line while keeping the axis of the air cylinder 28 horizontal. . That is, when the hydraulic cylinder 24 is actuated to shorten its piston rod, the parison pinch device 44 is positioned at the lower right standby position shown by a solid line in the drawing, and when the piston rod is extended, the parison pinch device 44 becomes a virtual line in the drawing. It is designed to be positioned at the upper left extension position shown by. The parison pinch device 44 and the pinch device moving device 46 constitute a parison bending device.

As shown in FIG. 2, the movable pinch plate 30 has guide bars 3 at positions on both sides of the air cylinder 28.
4 penetrate the wall of the second bracket 26 and are fixed respectively. The guide bars 34 are arranged such that their axes are parallel to the axis of the air cylinder 28. Bushes 36 are fixed to the walls of the second bracket 26 through which the guide bars 34 pass. The guide bars 34 are respectively fitted to the bushes 36 so as to be movable in the axial direction. That is, the two guide bars 34 can move integrally with the piston rod of the air cylinder 28 and the movable pinch plate 30 while being guided by the bush 36. Thereby, the movable pinch plate 30 can be uniformly pressed against the fixed pinch plate 32 in the width direction. As shown in FIG. 3, guide bars 38 are fixed to the second bracket 26 at positions on both side surfaces of the hydraulic cylinder 24 so as to penetrate the wall of the first bracket 22. The guide bars 38 are arranged such that their axes are parallel to the axis of the hydraulic cylinder 24. First bracket 22
A bush 40 is fixed to a wall portion through which the guide bar 38 passes. The guide bar 38 is connected to the bush 4
Each is fitted so as to be axially movable to zero. That is, the two guide bars 38 can move integrally with the piston rod of the hydraulic cylinder 24 and the second bracket 26 while being guided by the bush 40. Thereby, the second bracket 26 can be moved while being prevented from being twisted in the left-right direction in the figure. As shown in FIG. 4, the rotation support portion 18a of the angle adjustment bracket 18
, A pin 44 is fixed. The turning portion 20a of the angle adjusting bracket 20 is rotatably supported by the turning supporting portion 18a of the angle adjusting bracket 18 with a pin 44. As a result, the hydraulic cylinder 24 is
When adjusting the angle with respect to the horizontal plane, the hydraulic cylinder 2
It is possible to prevent the axis of 4 from deviating from a predetermined direction.

Next, the operation of this embodiment will be described. When the parison 48 starts to be ejected from the accumulator head 10 and its lower end hangs down to a position facing the parison aperture device 11, the aperture members 11a of the parison aperture device 11 are respectively moved from the outer retracted position to the inner aperture position. By moving each, the lower end of the parison 48 is narrowed down in a funnel shape. Immediately after the end of the aperture operation, the aperture member 11a moves to the outward retreat position and waits at that position. Accordingly, the funnel-shaped parison 48a having the narrowed lower end portion hangs down along with the injection, and the opened mold 1 is opened.
The injection ends when it is positioned between 2 and 14. In this state, the lower end of the parison 48 extends below the dies 12 and 14. The hydraulic cylinder 24 of the pinch device moving device 46 is located at the piston shortened position, and therefore the parison pinch device 44 is located at the standby position shown by a solid line in the figure. The movable pinch plate 30 is moved to the pinch position by operating the piston rod of the air cylinder 28 from the shortened position shown by the solid line in the drawing to the extension direction, and grips the lower end of the funnel-shaped parison 48a. Next, the parison pinch device 4 is moved by operating the hydraulic cylinder 24 of the pinch device moving device 46 in the piston extension direction.
4 is moved to the bending position indicated by the virtual line while holding the funnel-shaped parison 48a. As a result, the funnel-shaped parison 48a indicated by a broken line in the figure becomes a bent parison 48b indicated by a virtual line in the figure. In this state, the mold is closed, and the bent parison 48b is sandwiched between the molds 12 and 14. After closing the mold, the air cylinder 2 of the parison pinch device 44
8 is operated in the piston shortening direction to move the movable pinch plate 30 to the pinch release position, and the hydraulic cylinder 24 of the pinch device moving device 46 is operated in the piston shortening direction to return the parison pinch device 44 to the standby position. Let it. After completion of mold clamping, blow molding is performed in a normal procedure. Thereby, a bent-shaped molded product can be formed. Since it is not necessary to use a split movable mold to bend the parison 48 into a predetermined shape, the molded product can be easily and uniformly cooled. Therefore, it is possible to mold a molded article having sufficient strength without skin roughness.

In the description of the above embodiment, a boot-shaped hollow molded product is formed. However, the present invention is applied to a hollow molded product having a substantially "L" shape. be able to.

[0010]

As described above, according to the present invention, a bent hollow molded article can be formed without using a mold having a complicated structure. Since it is possible to easily cool the mold evenly, it is possible to mold a hollow molded article having a predetermined strength without surface roughness.

[Brief description of the drawings]

FIG. 1 is a view showing a parison bending device of the present invention together with a mold and the like.

FIG. 2 is a view as seen from the direction of arrow 2 in FIG. 1;

FIG. 3 is a view as seen from the direction of arrow 3 in FIG. 1;

FIG. 4 is a view as seen from the direction of arrow 4 in FIG. 1;

FIG. 5 is a view showing a conventional parison bending device together with a mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Accumulator head 12, 14 Die 18 Support base 22 1st bracket 24 Hydraulic cylinder (1st actuator) 26 2nd bracket 28 Air cylinder (2nd actuator) 30 Movable pinch board 32 Fixed pinch board 34 Guide bar 36 Bush 38 Guide Bar 40 bush 44 parison pinch device 46 pinch device moving device 48 parison 48a funnel-shaped parison 48b bent parison

Claims (4)

(57) [Scope of request for utility model registration] 1. A parison having a vertically oriented parison (48) positioned between horizontally opened molds (12, 14) and bent into a predetermined shape substantially matching the contour of the cavity (C). The bending device has a parison pinch device (44) disposed below a position where the molds (12, 14) are disposed, and a pinch device moving device (46). 44) a fixed pinch plate (32), a movable pinch plate (30), and a second actuator (28) capable of moving the movable pinch plate (30) in a direction approaching and away from the fixed pinch plate (32). Wherein the pinch device moving device (46) is arranged so that the parison pinch device (44) is located between a standby position near the center of the lower part of the mold and a bending position above the end near the lower end of the mold. Move A parison bending device having a first actuator (24) that is driven in such a manner. 2. The parison pinch device (44) has a second bracket (26), to which a fixed pinch plate (32) is fixed, and to which the second actuator (28) is fixed. The movable pinch plate (30) is fixed to the second bracket (26) so as to face the fixed pinch plate (32), and the pinch device moving device (46) is connected to the first bracket (2).
2), and a first actuator (24) is attached to the first bracket (22). The first bracket (22) has an axis of the first actuator (24) at a predetermined inclination angle with respect to a horizontal plane. The second bracket (26) of the parison pinch device (44) is attached to the fixing part (18) so that the angle can be adjusted.
2. The parison bending device according to claim 1, wherein the device is connected to the piston rod of the first actuator (24). 3. A first bracket (22) having first actuators (24) on both sides of a position where the first actuator (24) is mounted.
A first bush (40) fixed parallel to the axis of the actuator (24) and a first actuator (24) of the second bracket (26), respectively;
And a first guide bar (38) fixed parallel to the axis of the first actuator (24) on both sides of the position where the piston rod is mounted. ) Is the corresponding first bush (4
The parison bending device according to claim 1 or 2, wherein the parison is fitted so as to be movable in the axial direction. 4. A second bracket (26) having second actuators (28) on both sides of a position where the second actuator (28) is attached.
A second bush (36) fixed to the axis of the actuator (28) in parallel with each other, and a second bush (36) on the movable pinch plate (30) on both sides of the position where the piston rod of the second actuator (28) is mounted.
And a second guide bar (34) fixed in parallel to the axis of the actuator (28), respectively. The second guide bar (34) has a corresponding second bush (3).
The parison bending apparatus according to claim 1, 2 or 3, wherein the parison bending apparatus is fitted so as to be movable in the axial direction.