JPS582227A - Blow molding apparatus for glass - Google Patents

Abstract

PURPOSE:To form hollow glass such as a tumbler having a smooth fine surface with a blow molding apparatus by providing a blown air exhausting path connected to a relief valve to the blow head so as to maintain the internal pressure of a parison at a relatively low pressure. CONSTITUTION:A parison 3 supported on a ring 2 is mounted on the blow mold 1 for forming a tumbler, and a blow head 4 attached to the lower end of a pipe 8 fixed t the piston 7 of a cylinder 6 is pressed on the mouth of the parison 3. Compressed air is then fed from an adapter 10 through a pipe 9 placed in the pipe 8 under about 600-1,000mm. water column and blown into the parison 3 from a blow nozzle 5 to expand the parison 3. When the parison 3 contacts with the inside of the mold 1, air is exhausted from a relief valve 12 set to a low pressure such as <=100mm. water column through the exhaust path 11 between the pipes 8, 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an apparatus for blow molding hollow glass such as a tumbler having a smooth and beautiful surface.

Conventionally, in order to blow mold hollow glass such as a tamp, a disc-shaped or cylindrical parison is placed in a blow mold, a blow head is applied to the opening of the parison, and the blow mold is heated at 600 to 200 m
A device has been used that trap-blows a parison into a predetermined shape by blowing about 0-q of blow air. However, according to this method, the blow air blown into the parison remains inside the parison, so there is no place for the heat to escape.
In addition to suppressing the molding speed, the glass expands along the inner surface shape of the pro-mold. The ninth K is pressed against the Boo-7-rho by the pressure of the looosmA-.

In particular, when performing rotary blow molding in which relative rotation is applied between the blow hair and the parison, there is a drawback that a ring-shaped pattern is formed on the surface of the KFi molded product, spoiling the appearance.

There have been attempts to solve these drawbacks by rounding the parison, lowering the blow air pressure after the parison has finished expanding, or opening the interior to atmospheric pressure, but the product shape, wall thickness, parison temperature, etc. Since the timing changes in various ways, it is extremely difficult to set the timing accurately, and it is impractical.

In order to solve the above-mentioned drawbacks of the prior art, the present invention
It is made by Marugame, and an air outlet is formed in the blow head for blowing air into the parison placed at the internal pressure of the blow mold, and this outlet is connected to a relief valve set at a low pressure of 10,068 or less water column. It is characterized by being connected.

The present invention will be explained in more detail below with reference to the illustrated embodiment. The figure shows a blow mold for forming an IFi tumbler, and a parison 3 supported by a ring 2 is placed on the upper surface of the blow mold. A blow head 4 is attached to the lower end of a pipe 8 fixed to a piston 7 of a cylinder 6. There is a second pie 19 inside the pie 18, the lower end of which protrudes below the blow head and blows the blow nose A15.
It's on. An adder 10 is provided at the upper end of these pipes 8 and 9, and an adder 10 is provided on the inner pipe 19.
Compressed air of 00 to 2000 smA- is supplied.

The pressure of this air should be adjusted depending on the glass product to be blow molded, but in the case of a tumbler with an average wall thickness of around Qhwh, it is sufficient to set it to 1000 mqK.
The gap between the pipe 8 and the pipe 19 described above is the blow head 4.
It opens at the lower surface of the blower, forming a blow air discharge passage 11. The upper end of this discharge passage 11 is connected to an adder 10, and a relief valve 13 is further provided at its tip. This relief valve can be of any type, such as a good type, diaphragm type, or spring type, which utilizes the water head, as long as it can set a low pressure of 100III-m1 or less. In the example, by inserting the tip of Pi 1 into water for 50 seconds,
A 99-7 water valve set at a pressure of 111 mm was employed.

Next, the operation of this device will be explained. First, a ring 3 supported by a ring ilK is placed on the upper surface of the blow mold 1, and then a blow head is pressed against the mouth of the parison 30 by the action of a cylinder 60. Next, the inner pipe 9
When compressed air of K 1000100O is introduced, this compressed air blows out from the pronozzle I4/b into the inside of the parison 3 and expands the parison 3.
During the expansion, the pressure inside the parison 3 does not increase much, but when the parison 3 comes into close contact with the inner surface of the blow mold 1 as shown in FIG. 1, the internal pressure of the parison 3 gradually increases. Ku. And the internal pressure is 99-) valve 11
When the drop exceeds the level set by bO1 &&, the blow air inside the parison 3 passes through the blow air discharge passage 11 to lj leaf valve l! 1 is released into the atmosphere. As a result, an air flow as shown by the arrow is formed inside the parison 3 due to the second cause, and while the blow air continues to be blown from the pipe 9, internal cooling is performed. . In addition, since the internal pressure of the parison 3 does not exceed 50-m9, the inner surface of the formed glass blow mold l is not pressed, and in particular, there is no relative rotation between the blow mold 1 and the parison 3. Even in the case of the rotary blow blow, a ring-shaped pattern was no longer formed on the product surface, and a tamp-toe with beautiful skin was obtained.

As explained above, since the blow molding apparatus of the present invention has a blow air discharge path formed in the blow head, the blow air is discharged to the outside, and the inner surface of the molded parison is effectively cooled, thereby increasing the molding speed. It became possible. As a result of experiments, the molding speed is improved by F)1 or more compared to when a conventional blow head is used. In addition, the blow molding apparatus of the present invention has a 10-air discharge path of 100 m.
Since it is connected to the 91-f valve which is set to a low pressure of less than 5, the internal pressure of the parison is maintained at this set pressure KMI, and the glass is not pressed against the inner surface of the probe with a force of K11vh as in the conventional case. lost. As a result, the molded glass surface is smooth and beautiful9.As a result of experiments, it was found that in the tamp two molded using the conventional KjD rotary blow molding device, there was an unevenness of approximately b to 7 μ per yen, whereas the surface of the molded glass was made using the present invention. When using the device, it was found that the unevenness per lsm was 3 to 4 μ.

The reason why the upper limit of the set pressure of the relief valve is set to 1008811 is that if the pressure exceeds this value, the irregularities on the surface of the molded glass will gradually become larger.

Also, it is preferable that the lower limit of the set pressure is about 40 mm, and if the pressure is set below this, a parison internal pressure of 4G-60 mm, which is the pressure necessary to inflate the parison, will not be obtained. There may be cases where there is no.

In this way, in the device of the present invention, the blow air is released into the atmosphere via the relief valve set to a low pressure, so the pressure of the blow air can be increased relatively freely, and the flow rate of the blow air can be increased by K. It has the advantage that internal cooling can be carried out appropriately for each type of glass because it can be easily controlled. Furthermore, since the relief valve itself catches the rise in internal pressure due to the completion of the parison expansion process and opens the valve, there is no need for any timing settings to lower the internal pressure, and moreover, there is no need to set the timing for lowering the internal pressure. There is also the advantage that the molding is done by Nissin because the pressure is maintained. As described above, the present invention completely solves the drawbacks of the prior art, and makes a significant contribution to the industry, especially as an apparatus for rotary blow molding of thin-walled products such as tumblers.

[Brief explanation of the drawing]

Each of the drawings is a central vertical cross-sectional view of the apparatus of the embodiment, and No. 164 shows a parison expansion step, and No. 164 shows a step in which parison expansion is completed and internal cooling is being performed. l Niblow mold 3, ball ring 1 blow head 11 + blow air discharge path 1g + relief valve patent applicant Ishizuka Glass Co., Ltd. J1# 121!

Claims (1)

[Claims] ■A blow air discharge path is formed in the blow head for blowing blow air into the inside of the parison, which is filled with 11 cffl inside the blow mold, and this discharge path is connected to the water column 100.
A blow molding device for hollow glass, such as a tump-two, characterized in that the pressure is set at a low pressure below RAM and connected to nine relief valves.