JPS5912608B2 - Molding method for hollow glass products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the method of forming hollow glass products by round blowing.

When mass producing hollow glass products shaped like tumblers, a glass parison suspended by a neck ring is housed in a splittable blowing mold, and the bottom is movable up and down to fit into the bottom opening of the blowing mold. A method called rotary blowing is known in which the glass parison is supported in a blowing mold and the glass parison is blow-molded into a hollow glass product while rotating the neck ring and bottom mold in the same direction.

In this method, a high-quality hollow glass product cannot be obtained unless the rotation axis of the bottom mold is aligned with the vertical center line of the blowing mold.

However, in actual molding machines, it is extremely difficult to align the rotation axis of the bottom mold and the vertical center line of the blowing mold on the same straight line.

By the way, if the rotation axis of the bottom mold and the vertical center line of the blow mold do not match, the bottom mold rotates eccentrically with respect to the vertical center line of the blow mold, and (a) the blow mold is not in the middle of blow molding. It opens.

(0) Since the glass parison rotates eccentrically, a parallel pattern, a so-called record, occurs on the side of the product.
The wall thickness also becomes uneven.

(3) The peripheral edge of the bottom of the product also has uneven wall thickness, and (2) the blowing mold does not open well after blow molding, and the product may be thrown away when it is opened.

The present invention aims to improve the quality of hollow glass products by providing a molding method that can prevent eccentricity of the rotating shaft of the bottom mold in order to eliminate the above-mentioned disadvantages.

That is, one method of molding a hollow glass product according to the present invention includes placing a glass parison suspended by a neck ring in a blowing mold, supporting the glass parison with a bottom mold that fits into the bottom opening of the blowing mold, In a method of blow-molding a glass parison into a hollow glass product while rotating a neck ring and a bottom mold in the same direction, the rotation axis of the bottom mold is It is characterized by being made to coincide with the vertical center line of the blow mold.

FIG. 1 is a vertical cross-sectional view of a blowing mold and a bottom mold commonly used in conventional molding methods. As shown in the figure, the glass parison 1 is suspended by a neck ring 2 while the blowing mold can be divided. It can be kept within 3.

The bottom of the glass parison is supported by a bottom mold 4 that fits into the bottom opening of the blowing mold 3, and the bottom mold 4 is directly attached to a rotating rod 5 that can be moved up and down.

Neck ring 2 when blow molding glass parison
While rotating the bottom mold 4 in the same direction, air is blown from the upper opening of the glass parison, but in the conventional technology, the bottom mold 4
A gap is provided between the bottom opening of the blowing mold 3 and the bottom mold 4 that fits therein so that the blowing mold does not open even if the blowing mold 3 rotates somewhat eccentrically from the vertical center line of the blowing mold 3. ing.

However, these measures do not correct the eccentric rotation of the bottom mold relative to the blowing mold itself, and therefore cannot completely eliminate the records that occur on the sides of the molded product or the uneven thickness that occurs at the bottom.

However, according to the present invention, the bottom mold and the rotating rod that rotates the bottom mold are engaged with each other by an Oldham joint.

That is, as shown in Fig. 2, the bottom mold 4 is attached to the bottom mold mounting disk 6, which has one groove cut in its lower surface, and on the other hand, the upper end of the rotating rod 5 has one groove cut in its upper surface. A disk 7 is mounted on the rotary rod 5 so that its groove and the groove of the bottom mold mounting disk 6 are at right angles to each other.

The disc 8 is provided with one protrusion on each of its upper and lower surfaces, and these protrusions are perpendicular to each other and are machined to dimensions that fit exactly into the grooves of the discs 6 and 7. ing.

Therefore, by sandwiching the protruding disk 8 between the disks 6 and 7 and fitting the protrusions into the grooves of the disks 6 and 7, the bottom mold 4 can be engaged with the rotating rod 5. A shaft joint composed of the discs 6, 7 and 8 having the above-mentioned structure is generally called an Oldham joint.

When the bottom mold 4 and the rotary rod 5 are engaged through the Oldham joint, the bottom mold 4 can be rotated at a rotation axis different from that of the rotary rod 5, so that the blow mold can be rotated as shown in FIG. If the bottom mold 4 is fitted into the bottom opening of 3 and a minimum gap is provided between the two to allow rotation of the bottom mold, the bottom mold 4 will always rotate about the vertical center line of the blowing mold 3 as the rotation axis. That's what I do.

Of course, if the depth of the grooves on the first circular plates 6 and 7 and the height of the protrusions on the protruding disk 8 are approximately the same, the rotational axis of the bottom mold 4 can move parallel to the axis of the rotating rod 5. Therefore, if there is an angle between the vertical center line of the blow mold and the axis of the rotating rod, it is impossible to correct the rotation axis of the bottom mold.

However, even in such a case, the depth of the grooves in the discs 6 and 7 may be made shallow, or the height of the protrusion on the protruding disc 8 may be increased to allow the protruding disc 8 to swing and rotate. For example, even if the axis of the rotating rod is tilted to some extent, it is possible to align the rotation axis of the bottom mold 4 with the vertical center line of the blowing mold 3 using the Oldham joint.

However, if the protruding disk 8 swings and rotates, there is a risk that it may come off the groove of the disks 6 and/or 7, so in that case, the cylindrical cover 9 should be removed as shown in FIGS. 2 and 3. It is preferable to attach it to the Oldham joint.

As is clear from the above explanation, according to the present invention, the rotation axis of the bottom mold can always be aligned with the vertical center line of the blowing mold, and therefore, hollow glass products can be blow molded (rotary blowing). The occurrence of records traditionally experienced in
Non-uniform wall thickness can be avoided.

Further, according to the present invention, the blowing mold does not open during blow molding, and after molding is completed, the blowing mold opens smoothly and the product is not thrown away.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of the blow mold and bottom mold used in the conventional method, Fig. 2 is an explanatory diagram of the engagement of the Oldham joint used in the present invention, the bottom mold and the rotating rod, and Fig. 3 is the main FIG. 3 is a longitudinal sectional view of a blow mold and a bottom mold used in the invention. 1 Nigara parison, 2: Neck ring, 3-Blow mold, 4: Bottom mold, 5: Rotating rod, 6: Bottom mold mounting disc, 7;
Disc, 8; Projection disc, 9: Cylindrical cover〇

Claims (1)

[Claims] 1 Place the glass parison suspended by the neck ring in the blow mold, support the glass parison with the bottom mold that fits into the bottom opening of the blow mold, and do not rotate the neck ring and the bottom mold in the same direction. In a method of blow molding a glass parison in a blowing mold into a hollow glass product, the axis of rotation of the bottom mold is aligned with the vertical centerline of the blowing mold by engaging said bottom mold with a rotating rod through an Oldham coupling. A method for molding hollow glass products, characterized by: