JPH0365248B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold clamping device having two sets of mold clamping mechanisms arranged in two rows on a base plate.

When molding is performed with molds arranged in two rows, if a mold clamping cylinder is installed between two sets of mold clamping mechanisms arranged in parallel, there will be too much space between the molds. The advantages of doing so are lost. In particular, in a rotary injection stretch blow molding machine that performs continuous injection molding of parisons and stretch blow molding of hollow molded products, as the gap between the blow molds increases, the diameter of the rotary disk must also be increased. The machine becomes larger.

Therefore, as disclosed in Japanese Patent Application Laid-open No. 57-128519, the mold clamping plates of two sets of mold clamping mechanisms are located inside, the blowing molds are arranged in two rows, and the mold clamping cylinder located outside The pair of mold clamping plates are mutually opened and closed, and the mold is clamped by applying pressure.

A drawback of such a conventional structure is that the mold clamping plate located inside is bent by internal pressure during molding. This constriction is thought to be caused by the fact that there is nothing to support the inner mold clamping plate at the center during mold clamping, and because it is being pulled on both sides. As a result, there may be a difference in the volume of the cavity on both sides and the center of the mold.

This invention was devised in order to eliminate the above-mentioned conventional drawbacks, and its purpose is to prevent the mold from entering the mold during mold clamping even if there is a space between the inner mold clamping plates of the mold clamping mechanism arranged in two rows. The mold clamping plate is pressurized to prevent the inner mold clamping plate from deflecting due to internal pressure.

Another object of the present invention is to enable a pressurizing device for the inner mold clamping plate using a hydraulic cylinder to be accommodated in both inner mold clamping plates when the mold is opened, so that even though the hydraulic cylinder is provided, It is an object of the present invention to provide a mold clamping device with a new configuration that allows the interval between clamping plates to be set to the minimum required for mold opening.

The feature of the present invention for the above-mentioned purpose is that a hydraulic cylinder for pressurizing both inner mold clamping plates is provided in the working space between the inner mold clamping plates so as to be movable up and down. The hydraulic cylinder is provided inside the mold so that the hydraulic cylinder does not impair the movement of the mold clamping plate when the mold is opened.

The present invention will be explained in detail below using illustrated examples.

In the figure, 1 is a base plate, and fixed plates 2, 2 are provided on the inside of the upper surface, and guide rods 3, 2 are provided on the inside of the fixed plates 2, 2.
3 has been erected.

Reference numeral 4 denotes a mold clamping mechanism, which includes a pair of mold clamping plates 5, each having a blowing mold A having a plurality of cavities mounted on opposing surfaces.
6 and an operating plate 7 parallel to the outer mold clamping plate 6, and between the operating plate 7 and the outer mold clamping plate 6, a plurality of hydraulically operated mold clamping cylinders 8 are arranged to clamp the cylinders to the outer mold. The ram 9 is fixed to the plate 6 and the ram 9 is fixed to the actuating plate 7.

The inner mold clamping plate 5 is connected to the actuating plate 7 by tie rods 10 on both sides provided through the outer mold clamping plate 6.
The actuating plate 7 is connected to the actuating plate 7 so that it moves in the same direction as the actuating plate 7.

The two sets of mold clamping mechanisms 4, 4 having the above structure are arranged between the fixed plates 2, 2 of the base plate 1, with the mold clamping plate side facing inside. In this case, an operating space 11 necessary for mold opening is provided between both inner mold clamping plates 5, 5, and both mold clamping plates 5, 6 and operating plate 7 are inserted through the guide rod 3. , guide rod 3 by mold clamping cylinder 8
It is provided to open and close between position control members 13 and 14 which are fixed to each other.

15 is a hydraulic cylinder that pressurizes both inner mold clamping plates 5, 5, and is equipped with rams 16 on both sides of the cylinder, and is connected to a rod 18 of an air- or hydraulic-operated lifting device 17 attached to the lower side of the base plate 1. , the working space 1
It is located in the center of 1. Furthermore, notches 20, 20 are provided at the lower center of both inner mold clamping plates 5, 5, and these notches 20, 20 form a housing portion for the hydraulic cylinder 15.

Therefore, in the mold clamping device having the above structure, when the outer mold clamping plate 6 and the actuating plate 7 are pressurized in opposite directions by the mold clamping cylinder 8, the inner mold clamping plate 5 also applies pressure to the outer mold clamping plate 7. It is pulled toward the plate 6 and mold clamping occurs.

On the other hand, when the outer mold clamping plate 6 and the operating plate 7 are drawn together by the mold clamping cylinder 8, the inner mold clamping plate 5 moves in the opposite direction to the outer mold clamping plate 6 and moves there. Mold opening occurs. The outer mold clamping plate 5 and the operating plate 7 are moved simultaneously by the hydraulic cylinder 8, or after one of them comes into contact with the fixed platen 2 or the position control member 13 and stops moving, the other moves. Occurs in stages.

The hydraulic cylinder 15 is interposed between the inner mold clamping plates 5, 5 only when the mold is clamped, and is lowered onto the base plate 1 when the mold is opened.
When 5 comes back, place it so that it fits into the notches 20, 20. As a result, hydraulic cylinder 1
5 does not obstruct mold opening even if it is always located in the working space 11, and when the working space 11 is opened by closing the mold, both inner mold clamping plates 5, 5 are removed before mold clamping.
, and further hydraulically actuates both rams 16, 16 to pressurize both inner mold clamping plates 5, 5 at the same time.
It can be used to counter internal pressure.

Therefore, even if the internal pressure of the blowing mold A acts on the inner mold clamping plate 5 during molding, the inner mold clamping plate will not bend as it would when the inner mold clamping plates 5, 5 are pulled on both sides. There is no.

As described above, in this invention, two sets of mold clamping mechanisms are arranged in two rows, with the mold clamping plates facing inside between the fixed plates on the base plate, and working spaces are provided. A hydraulic cylinder that pressurizes the clamping plate is installed so that it can be raised and lowered, and the clamping force is further enhanced by the hydraulic cylinder, so both inner mold clamping plates can withstand the internal pressure during molding, making it ideal for molds with a large number of cavities. Even if it is, the inner mold clamping plate will not be bent.

In addition, since a housing part for the hydraulic cylinder is provided in the lower part of both inner mold clamping plates, the hydraulic cylinder does not make it difficult to open the mold, and the device itself has a conventional structure with a hydraulic cylinder and its lifting device. It has such an advantage that it is not particularly complicated because it only needs to be added.

[Brief explanation of drawings]

The drawings show an embodiment of a mold clamping device having two sets of mold clamping mechanisms according to the present invention, in which FIG. 1 is a half cross-sectional plan view during mold clamping, FIG. 2 is a side view thereof, and FIG.
The figure is a half vertical side view when the mold is opened. 1... Base plate, 2... Fixed plate, 3... Guide rod, 4
...Mold clamping mechanism, 5...Inner mold clamping plate, 6...Outer mold clamping plate, 7...Operation plate, 8...Mold clamping cylinder, 11
...Working space, 15...Hydraulic cylinder, 16...
Ram, 17... Lifting device.

Claims (1)

[Claims] 1. A pair of mold clamping plates with molds mounted on opposing surfaces, and an operating plate parallel to the clamping plates, with a clamping cylinder provided between one of the clamping plates and the operating plate, and a clamping cylinder extending between one of the clamping plates and the operating plate. A mold clamping device in which two sets of mold clamping mechanisms each having a clamping plate and an operating plate are arranged in two rows with the mold clamping plates facing inside between fixed plates on a base plate and with an operating space provided, Two mold clamping sets characterized in that a hydraulic cylinder for pressurizing both inner mold clamping plates is provided in the working space so as to be movable up and down, and a housing portion for the hydraulic cylinder is provided in a lower part of both inner mold clamping plates. A mold clamping device with a mechanism.