JP3100272B2 - Parison pinch method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for pinching a parison, and more particularly, to a novel improvement for obtaining a flat parison by pinching the upper and lower parts of the parison and widening the parison laterally.

[0002]

2. Description of the Related Art A conventional parison pinching method and apparatus of this type has generally employed the structure shown in FIG. That is, in FIG. 7, the lower part 2 a of the parison 2 which is ejected or pushed out from the nozzle 1 of the accumulator or the crosshead is a pair of the widened bodies 3.
a, 3b, the lower portion 2a is widened in the lateral direction, and at the same time, a pair of lower pinch portions 4a, 4 of the lower pinch body 4 are formed.
b was pressed by the cylinder 5, and as a result, the lower part 2a was deformed flat. In addition,
Each of the widened members 3a and 3b is configured to be pulled in opposite directions by a pair of actuators 6 as shown in FIG. As another conventional example, a flat parison is formed by a flat die.

[0003]

The conventional parison pinching method and apparatus have been configured as described above.
The following issues existed. That is, as described above, the method of forming a flat molded product by a normal molding method is the method of widening the lower part of the parison most often, but only the lower part of the parison becomes flat. ,
As shown in FIG. 8, the middle part 2b and the upper part 2c of the parison
Becomes an ellipse and a circle, and when a flat molded product is molded in this state, the molded product becomes a molded product in which the center portion is thick and the left and right ends are thin, the periphery of the wall becomes uneven, and the thickness of the thin portion is reduced. In order to secure the parison, the entire parison had to be unnecessarily thick, and as a result, the weight of the molded article became heavy. Also, when a flat parison is directly formed using a flat die as in other conventional examples, the hollow molding machine becomes a dedicated machine, and cannot be used for a general circular parison, and the size of the parison is reduced. To change it, another flat die was needed. Therefore, control of the thickness of the nozzle in the die and the core becomes complicated, and
The entire apparatus was extremely expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and in particular, a parison having a flat parison obtained by pinching the upper and lower parts of the parison and widening the parison in the lateral direction. It is an object to provide a pinch method and apparatus.

[0005]

According to a method of pinching a parison according to the present invention, a lower portion of a parison hanging from a nozzle is pinched by a lower pinch body to widen the lower portion, and an upper portion of the parison is pinched by an upper pinch. The parison is flattened by pinching with a plurality of upper pinch pieces provided on a pair of upper pinch portions of the body, moving the respective upper pinch pieces in different directions, and widening the upper portion in the lateral direction. It is a method of forming.

A parison pinch device according to the present invention is a parison pinch device in which a lower portion of a parison hanging from a nozzle is pinched by a lower pinch body to widen the lower portion of the parison. An upper pinch body, a pair of upper pinch portions constituting the upper pinch body, and moving means for moving a plurality of upper pinch pieces provided in each of the upper pinch portions in directions different from each other. The upper pinch piece pinches the upper portion of the parison and widens the width in the lateral direction.

More specifically, the moving means is provided on each of the upper pinch portions so as to be rotatable and has a plurality of rotary shafts having eccentric cams which engage with the upper pinch pieces. Rotator, an endless ring provided in engagement with each of the rotators, and an actuator for moving the endless ring.

[0008] More specifically, the rotating body is formed of a sprocket, and the endless ring-shaped body is formed of a chain.

[0009]

In the method and the apparatus for pinching a parison according to the present invention, the lower part of the parison, which hangs down from the nozzle, is pinched by a lower pinch body, the upper part of the parison is pinched by an upper pinch body, and the upper and lower parts of the parison are moved laterally. Because a flat parison is obtained by forcibly widening it,
A parison using a generally used circular nozzle can be used as it is and can be flat over the entire parison. Accordingly, since the hollow molding is performed using the flat parison, the thickness of the molded article can be made uniform.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the method and apparatus for pinching a parison according to the present invention will be described below in detail with reference to the drawings. The same or equivalent parts as those in the conventional example will be described with the same reference numerals. 1 to 6 show a method and an apparatus for pinching a parison according to the present invention. FIG. 1 is a process diagram showing a pinching method for a lower portion of the parison, and FIG. 2 is a process diagram showing a pinching method for an upper portion of the parison. 3 is a side view showing a main part of FIG. 1, FIG. 4 is a plan sectional view of FIG. 3, and FIG.
FIG. 6 is a sectional view taken along line AA of FIG.

FIG. 1 is the same as the process described in the above-mentioned conventional example, and the lower part 2a of the parison 2 which is ejected or pushed out from the nozzle 1 of the accumulator or the crosshead and which hangs down,
The lower portion 2a is widened in the lateral direction by the pair of widening members 3a and 3b, and at the same time, the lower pinch portions 4a and 4b of the lower pinch member 4 are pressed by the cylinder 5 so that the lower portion 2a is pressed. 2a was deformed flat. The widening members 3a and 3b are configured to be pulled in opposite directions by a pair of actuators 6 as shown in FIG.

The upper portion 2b of the parison 2 has a pair of upper pinch portions 10a,
Pinched by an upper pinch body 11 made of 10b,
The upper pinch portions 10a and 10b are configured to be cut by a cutter (not shown).
2 to perform a pinch operation.

The upper pinch portions 10a and 10b are provided so as to be reciprocally movable in the direction of arrow A via a guide bar 20 provided on the upper cylinder 12 side as shown in FIGS. And each of the upper pinch portions 10a,
10b is configured in a longitudinal shape.

Each of the upper pinch portions 10a and 10b has
Along the longitudinal direction, first to fifth upper pinch pieces 22a to 22e each having a piece shape and having a rough surface portion 21 are provided so as to be reciprocally movable in a pair of independent sliding grooves 23. Eccentric cams 25 and 26 are provided in the concave portions 24 of 22b, 22c and 22e.

Each of the eccentric cams 25 and 26 is connected to one end of a rotary shaft 28 rotatably provided on the upper pinch portions 10a and 10b via a bearing 27.
At the other end of the rotating shaft 28, a rotating body 29 such as a sprocket or a reel is provided so as to rotate integrally.

Each of the rotating bodies 29 is provided with an endless ring-shaped body 30 such as a chain or a timing belt mounted thereon, and each of the rotating bodies 29 is configured to be able to rotate synchronously. The endless ring-shaped body 30 is connected to a movable portion 31a of an actuator 31 formed of a cylinder or the like provided on the upper pinch portions 10a, 10b. The eccentric cams 25 and 26 are configured to rotate in the same direction. In addition, the above-mentioned rotating body 2
9, the endless ring-shaped body 30 and the actuator 31 constitute a moving means 50 for moving the upper pinch pieces 22a, 22b and 22d, 22e in directions opposite to each other.

Each of the eccentric cams 25 and 26 has a different eccentric state.
6 is rotated in the same direction, the first and second upper pinch pieces 22a and 22b move in the direction of arrow X, and the other fourth and fifth pinch pieces 25d and 22e move in the direction of arrow Y opposite to the direction of arrow X. The third pinch piece 22c
The first and second pinch pieces 22a and 22b and the fourth and fifth pinch pieces 25d and 22e are arranged at symmetrical positions with respect to. Therefore, the third pinch piece 22c is located from the center of the upper part 2c of the parison 2 in the width direction.

Next, the parison pinch method will be described. First, as shown in FIG. 1, the lower portion 2a of the parison 2 hanging from the nozzle 1 is pinched by the lower pinch body 4 and at the same time, the lower portion 2a is widened by the pair of widening members 3a and 3b. It becomes elliptical.

Next, in parallel with the above-mentioned pinch of the lower part 2a, the upper part 2c of the parison 2 is connected to each of the upper pinch parts 10a, 10 via the respective upper cylinders 12 of the upper pinch body 11.
b moves forward and the rough surface 21 of each of the upper pinch pieces 22a to 22e.
Is pinched by At the same time, each upper pinch portion 10a,
The actuator 31 of 10b is operated and the endless ring 30
Is rotated in one direction, as described above, each eccentric cam 2
First and second upper pinch pieces 22a, 22 through 5, 26
b moves in the X direction and the fourth and fifth upper pinch pieces 2
As the 2d and 22e move in the Y direction, the upper part 2c of the parison 2 is pulled in the width direction and widened, and becomes an elliptical shape.

By the above-mentioned pinch operation, the upper part 2c, the middle part 2b, and the lower part 2a of the parison 2 become almost uniformly elliptical, and the elliptical parison 2 can be obtained. The configuration of the pinch and the widening described above is an example, and other means (not shown) can be used.

[0021]

The parison pinching method and apparatus according to the present invention are configured as described above, so that the following effects can be obtained. That is, since the upper pinch and the widening are performed at the same time as the lower pinch and the widening of the parison, the entire shape of the parison can be made elliptical, and as in the conventional case, the entire parison is made unnecessarily thicker in advance. Without, it is possible to obtain a flat hollow molded product with a uniform thickness,
It is possible to reduce the weight of the molded product, reduce the cost, and improve the strength.

[Brief description of the drawings]

FIG. 1 is a process diagram showing a lower pinch state in a parison pinch method according to the present invention.

FIG. 2 is a process diagram showing an upper pinch state in a parison pinch method according to the present invention.

FIG. 3 is a side view showing a main part of FIG. 1;

FIG. 4 is a plan sectional view of FIG. 3;

FIG. 5 is a sectional view taken along line BB of FIG. 4;

FIG. 6 is a sectional view taken along line AA of FIG. 4;

FIG. 7 is a process chart showing a conventional pinch method.

FIG. 8 is a configuration diagram showing a conventional pinch state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle 2 Parison 2a Lower part 2c Upper part 4 Lower pinch body 10a, 10b Upper pinch part 11 Upper pinch body 22a, 22b and 22d, 22e Upper pinch piece 28 Rotation axis 29 Rotor 30 Endless ring 31 Actuator 50 Moving means

Claims (4)

(57) [Claims] 1. A lower part (2a) of a parison (2) hanging from a nozzle (1) is pinched by a lower pinch body (4) to form a lower part (2a).
a) is expanded in the lateral direction, and the upper part (2c) of the parison (2) is connected to a pair of upper pinch portions (10a, 1a) of the upper pinch body (11).
0b) and a plurality of upper pinch pieces (22a, 22b and 22d, 22d).
e) Pinch the upper pinch pieces (22a, 22b and 22d, 22e)
The parison (2) is formed into a flat shape by moving the parison (2) in different directions to widen the upper portion (2c) in the lateral direction. 2. A lower part (2a) of a parison (2) hanging down from a nozzle (1) is pinched by a lower pinch body (4), and the lower part (2) is pinched.
In a parison pinch device in which a) is widened laterally, an upper pinch body (11) for pinching an upper part (2c) of the parison (2) and the upper pinch body (11) are configured. A pair of upper pinch portions (10a, 10b), and a plurality of upper pinch pieces (22a,
22b and 22d, 22e) for moving in different directions from each other, and each of the upper pinch pieces (22a, 22b and
22. A pinching device for a parison, wherein the upper part (2c) of the parison (2) is pinched and widened in the lateral direction by 22d, 22e). 3. The moving means (50) is rotatably provided on each of the upper pinch portions (10a, 10b) and is provided with the upper pinch pieces (22).
a, 22b and 22d, 22e), a plurality of rotating shafts (28) having eccentric cams (25, 26) engaged with the rotating body (29) provided on each of the rotating shafts (28), The endless ring-shaped body (30) provided in engagement with each rotating body (29), and an actuator (31) for moving the endless ring-shaped body (30). Parison pinch device. 4. The parison pinch device according to claim 3, wherein said rotating body (29) is made of a sprocket and said endless ring-shaped body (30) is made of a chain.