JPH081759A - Parison head of blow molding machine - Google Patents

Abstract

PURPOSE:To prevent a vertical line on a surface of a parison from occurring by miniaturizing a head and uniformizing a wall thickness of a molding by a method wherein a gap for giving a wall thickness inside a parison is vertically provided on an outer peripheral part of a core, a gap-clearance volume adjuster is freely vertically movably provided to an outlet of the gap, and a die is freely movably provide in a vertical shaft direction. CONSTITUTION:A core 4 passes through a die 2. An outer peripheral part of the core 4 is worked vertically into a gap 6 for giving a wall thickness inside a parison. A gap-clearance volume adjuster 7 is freely vertically movably provided to an outlet of each gap 6. Then, for fundamental wall thickness-control, a slit 5 between the die 2 and the core 4 is adjusted by vertical movement of the die 2. Partial control for giving a wall thickness is carried out by vertical movement of the gap-clearance volume adjuster 7. That is, when the gap 6 corresponding to a corner angle part of the core 4 is provided to the core 4, and the wall thickness is added inside the parison 15, the corner angle part does not become thin in wall thickness and comes to have a uniform wall thickness. Further, since the addition of the wall thickness is carried out from the inside of the parison 15, a surface quality of a product is not deteriorated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parison head of a blow molding machine for blow molding an extruded parison.

[0002]

2. Description of the Related Art Many conventional parison heads for blow molding machines having a parison thickness control means are known.
8 and 9 of the -58258 publication, and secondly, the actual Kaihei 5-
No. 12122, FIGS. 1 and 2, and third, Japanese Patent Publication No. 3-2.
No. 5325, and fourthly, those described in Japanese Examined Patent Publication No. 58-44466.

That is, in the above-mentioned first one, the slide plate is inserted from the outer lateral direction into the ring-shaped slit for pushing out the parison between the core and the die to control the outer wall thickness. ing. In the second type, a vertically divided core is moved up and down to control the wall thickness. The third one is configured to control the wall thickness by changing the diameter of the core made of an elastic material to adjust the gap of the slit formed between the core and the die. In the fourth type, the wall thickness is controlled by vertically moving a fan-shaped bushing that is divided in the radial direction.

[0004]

However, in the above-mentioned conventional technique, the structure is complicated, and
There was a problem that it became a large head. Moreover, in the case of controlling the outer flesh, there is a problem that vertical lines always remain on the parison surface due to movement in the horizontal direction with respect to the vertical axis, and steps are formed, resulting in poor surface quality of the product. It was

The present invention is intended to solve the above problems. That is, the present invention, the structure of the head itself is simple, it is possible to miniaturize, the thickness of the molded product can be made uniform, and moreover, vertical lines on the parison surface can be prevented, An object of the present invention is to provide a parison head of a blow molding machine that can obtain a product having a good surface property.

[0006]

In order to achieve the above object, the present invention provides a die installed at the lower end of a parison head body, and a die that is penetrated in the longitudinal direction in the center of the die. In a parison head with a core forming a ring-shaped slit for extruding the parison, and having a gap for flesh inside the parison machined in the longitudinal direction in the outer peripheral portion of the core, and It has a gap clearance adjustment device installed at the outlet so that it can move up and down,
Moreover, the die is provided so as to be movable in the vertical axis direction.

[0007]

According to the present invention, a ring-shaped slit for pushing out the parison is formed between the die installed at the lower end of the parison head body and the central portion of the die which penetrates in the longitudinal direction. In a parison head including a core to be formed, a gap for fleshing the inside of the parison that has been machined in the vertical direction is provided in the outer peripheral portion of the core, and the gap clearance amount provided at the exit of the gap so as to be vertically movable. Since the die has an adjusting device and is movable in the longitudinal direction, the basic parison thickness control is to adjust the slit between the die and the core by moving the die up and down. The partial thickness control can be performed by moving the gap clearance adjusting device of the core up and down. In other words, the desired thickness can be added to the inside of the parison.

[0008]

1 to 3 show an embodiment of the present invention, in which FIG. 1 is a front sectional view showing a longitudinal section in the center, and FIG.
2 is an enlarged bottom view showing only the central portion of FIG. 1, and FIG.
The sectional view taken along the section line A-A in FIG.
Mainly seen in FIG. 1, 1 is a parison head body, 2 is a die installed at the lower end of the parison head body 1, 3 is a geometrical vertical axis of the center of the die 2, and 4 is the center of the die 2. A core 5 penetrating the part is a ring-shaped slit for extruding the parison formed between the die 2 and the core 4.

Reference numerals 6 shown in FIGS. 1, 2 and 3 denote gaps formed in the outer peripheral portion of the core 4 in the vertical direction, and are provided at four places in this embodiment. As will be described later, the gap 6 is a gap for fleshing the inside of the parison, and a gap clearance adjusting device 7 (shutter) is provided at the exit of each gap 6 so as to be vertically movable.

Returning to FIG. 1, 8 is an extruder, 9 and 10 are actuators for vertically moving the gap clearance adjusting device 7, 11 is an actuator for vertically moving (moving vertically) the die 2, and 12 is a seat. A plate, 13 is an upper lateral member,
14 is a middle lateral member.

In the parison head of the blow molding machine constructed as shown in FIGS. 1, 2 and 3, the basic parison thickness control is to adjust the slit 5 between the die 2 and the core 4. The die 2 is moved up and down, and the partial weight control is performed by moving the gap clearance adjusting device 7 of the gap 6 machined in the core 4 up and down.

That is, when a product having a corner portion is blow-molded, the corner portion tends to be thin, and therefore the core 4 is previously provided with the above-described gap 6 corresponding to the corner portion. The gap 6 to the parison 15
(Refer to FIG. 2 and FIG. 3) When the inside is fleshed, the corner portion does not become thin and the product has a uniform thickness, and since the flesh is fleshed from the inside of the parison 15, Does not deteriorate the surface properties of.

[0013]

As described above, according to the present invention,
A parison head including a die installed at the lower end of the parison head body, and a core that penetrates through the center of the die in the longitudinal direction and forms a ring-shaped slit for pushing the parison between the die and the core. In the above, in the outer peripheral portion of the core, there is a longitudinally machined gap for lining the inside of the parison, and at the outlet of the gap, there is a gap clearance adjusting device that is vertically movable. Since the die is provided so as to be movable in the vertical axis direction, the basic thickness control of the parison can be performed by adjusting the slit between the die and the core by moving the die up and down. The control can be performed by vertically moving the gap clearance adjusting device of the core.

Therefore, vertical lines generated on the surface of the parison are prevented, and smooth partial fleshing can be performed from the inside of the parison, so that the surface property of the product is improved and a product having a uniform wall thickness can be easily obtained. . In addition, the parison head itself is compact and can be used for small diameters.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged bottom view showing only the central portion of FIG.

3 is a front sectional view taken along the section line AA of FIG.

[Explanation of symbols]

 1 Parison head body 2 Die 3 Vertical axis 4 Core 5 Slit 6 Gap 7 Gap Gap adjustment device

Claims (3)

[Claims] 1. A die installed at the lower end of a parison head body, and a core that penetrates through the center of the die in the longitudinal direction and forms a ring-shaped slit for pushing the parison between the die and the core. A parison head having a gap for fleshing the inside of the parison that is machined in the vertical direction on the outer peripheral portion of the core, and a gap clearance adjusting device that is vertically movable at the exit of the gap. Then
Moreover, the parison head of the blow molding machine is characterized in that the die is provided so as to be movable in the vertical axis direction. 2. The parison head of a blow molding machine according to claim 1, wherein a plurality of gaps for filling the inside of the parison are provided. 3. A basic parison thickness control is performed by adjusting a slit between a die and a core by moving the die up and down, and a partial thickness control is performed by vertically moving a gap clearance adjusting device for the core. The parison head of the blow molding machine according to claim 1, wherein the parison head is moved.