JPS61209125A - Mold assembly in rotary type blow molding machine - Google Patents

Abstract

PURPOSE:To eliminate the development of undercooling at the mouth part and bottom part of a hollow vessel and reduce waste flash portions and consequently improve the raw material efficiency by a constitution wherein the mouth part mold of the fixed mold of one mold assembly fixed onto the outer peripheral surface of a disc and the bottom part mold of the fixed mold of the adjoining mold assembly are made into an integral body. CONSTITUTION:A large number of sets of mold assembly, which consists of a fixed mold 2 and an open-close mold 3 to open and close about side of a disc 1 in the direction of rotation of the disc 1, are arranged onto the outer peripheral surface of the disc 1. Each mold is for molding a hollow vessel and has a mouth part cavity 4, a barrel part cavity 5 and a bottom part cavity 6. Mold blocks constituting said cavities are separated from one another. On the other hand, the fixed mold 2 also consists of a mouth part mold 2a, a barrel part mold 2b and a bottom part mold 2c. The mouth part mold 2a of the fixed mold 2 of one mold assembly and the bottom part mold 2c of the fixed mold 2 of the adjoining mold assembly are made into an integral body. Accordingly, the mold assemblies adjacent to each other are mutually joined into an integral body through the mouth part mold 2a and the bottom part mold 2c of the fixed mold 2. Due to the constitution as mentioned above, the mouth part mold 2a and the bottom part mold 2c of the fixed mold 2 in the respective mold assemblies are cooled integrally.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a mold apparatus for rotary type blow molded containers.

A conventional rotary type blow molding machine is shown in FIG. It consists of a large number of fixed molds fixed to each other, and an opening/closing mold C that can be opened and closed with one side of the rotating direction of the disk as a pivot point for each fixed mold. Close the opening/closing mold C while sandwiching the parison d, and while it is closed and moving, hollow molding is performed in both molds C and C, and then the opening/closing mold C
The molded products e are taken out one after another by opening the molded parts.

The mold device in such a rotary blow molding machine is
It has been known from Japanese Patent Publication No. 37-94, Japanese Patent Publication No. 39-3580, and Japanese Patent Publication No. 45-16839.

In these conventional examples, as shown in Fig. 3, each set of mold devices consisting of a fixed mold and an opening/closing mold C is independently attached to the outer periphery of the disk a. There is a gap S between both adjacent mold devices at the parting line.

Although not shown in the above-mentioned known examples, a hollow container as shown in FIG. 4, that is, a hollow container having a threaded opening f, a cylindrical body g and a flat bottom, As shown in FIG. 3, the mold apparatus for molding is constructed by separately manufacturing each mold into a mouth part fl, a body part g, and a bottom part, and then assemble them into one piece. This is because the processing means for each component are different. Each component has holes for water cooling.
is the provision.

Problems to be Solved by the Invention In the mold devices in each of the above-mentioned known examples, there is a gap S between adjacent mold devices on the parting line, so that there is a gap between the molds. Discarded burrs are generated due to unmolded parisons, and this amount of parisons is wasted, resulting in poor product yield.

On the other hand, in order to increase raw material efficiency by reducing the above-mentioned waste portion 3, adjacent cavities should be moved closer to each other in the rotating direction of disk a, but if you try to move the cavities closer together, each mold The constituent parts of the mouth f° and bottom h° become small, and in particular, the bottom h′ on the fixed mold side becomes small, making it impossible to provide water cooling holes i in this part.

Since the bottom h° of the mold is separate from the body g°, the cooling effect of the body g is far reaching the bottom h'.
If there is no cooling hole i, this part cannot be cooled, and the pinch-off part caused by the bottom part h' will be insufficiently cooled, resulting in bottom cracking after molding.

Means and Effects for Solving the Problems The present invention has been made in view of the above-mentioned problems, and is a method of connecting the mouth mold and the bottom mold of a fixed mold fixed to the outer peripheral surface of a disk to each other by adjacent mold devices. It has an integrated structure, and both molds are cooled together.

Example An embodiment of the present invention will be described based on FIG.

Reference numeral 1 in the figure indicates a disk that is rotationally driven in one direction, and a fixed mold 2 is attached to the outer peripheral surface of the disk 1, and the fixed mold 2 is opened and closed using the side of the rotation direction of the disk 1 as a fulcrum. A large number of mold devices are provided, each consisting of a movable opening/closing mold 3. Each of these molds is for molding the hollow container shown in FIG. 4 in the same manner as the conventional example, and has a mouth cavity 4, a body cavity 5, and a bottom cavity 6, each of which constitutes a hollow container. The mold part has a separate structure.

That is, the opening/closing mold 3 consists of a mouth mold 3a, a body mold 3b1, and a bottom mold 3C.

On the other hand, the fixed mold 2 also includes a mouth mold 2a, a body mold 2b, and a bottom mold 2C.
The mouth mold 2a and the bottom mold 2C of this fixed mold 2 are integrated in adjacent mold apparatuses. Therefore, the adjacent fixed molds 2 are integrally connected to each other via the mouth mold 2a and the bottom mold 2C. 7 is a water cooling hole.

In addition, in the above embodiment, an example was shown in which each of the molds 2 and 3 was divided into a mouth part, a body part, and a bottom part, but depending on the shape of the molded product, it is not necessary to separate the body part, and the mouth part or It is also possible to connect the bottom part directly.

In the above configuration, the mouth mold 2 of the fixed mold 2 of each mold device
a and the bottom mold 2C are cooled together.

Effects of the Invention With the above configuration, the mouth mold 2a and the bottom mold 2C of the fixed mold 2
Since the two can have different wall thicknesses, even if the mouths and bottoms of adjacent cavities are close to each other, the mouth part type 2
a. Adjust the thickness of the mold that integrates the bottom mold 2C to a certain extent.
That is, it is possible to obtain a mold device having a wall thickness sufficient to provide the required number of water cooling holes 7, and which can sufficiently cool the mouth and bottom portions.

Therefore, according to the present invention, there is no insufficient cooling at the mouth and bottom, and the amount of paris can be minimized, thereby improving raw material efficiency. It is possible to increase the number of mold devices that can be attached to the disk 1 and improve work efficiency.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the main parts of an embodiment of the present invention, FIG.
FIG. 3 shows a conventional example, FIG. 2 is a schematic explanatory view of the overall configuration, FIG. 3 is a sectional view showing the main parts, and FIG. 4 is a front view showing the hollow container. 1 is a disk, 2 is a fixed mold, 3 is an opening/closing mold, and 2a. 3a is a mouth mold, 2c and 3c are bottom molds, 4 is a mouth cavity, and 6 is a bottom cavity.

Claims (1)

[Claims] A large number of fixed molds 2 are fixed to the outer circumferential surface of the disk 1 which is rotationally driven in the direction of rotation of the disk 1, and each fixed mold 2 is opened and closed using one side of the rotation direction of the disk 1 as a pivot point. The two molds 2 and 3 constitute a cavity for molding a hollow container having a mouth and a bottom, and the molds 2 and 3 constitute a mouth cavity 4. In a mold device of a rotary type blow molding machine, which is formed by dividing and combining mouth molds 2a, 3a and bottom molds 2c, 3c constituting a bottom cavity 6, the mouth mold 2a of the fixed mold 2 and the bottom mold A mold device for a rotary type blow molding machine, characterized in that 2c and 2c are integrated in adjacent mold devices.