JP4180599B2 - Glass bottle - Google Patents

Description

  The present invention relates to a glass bottle having a screw for screwing a cap into a mouth portion.

  As shown in FIG. 1, the screw 2 at the mouth of the glass bottle 1 is formed smaller than the other portions in the vicinity of the joint C of the mold. This small portion is referred to as a “skin screw”. The mold is formed by combining two substantially semicircular split molds, and the joint of the split molds is a “joint”. At the seam, the glass protrudes from a slight gap and a small protrusion is formed. Therefore, the screw at that portion is formed slightly small to prevent the screw of the cap from being damaged.

  FIG. 2 is a comparison of the size and shape of the general screw 2 and the thin screw 3. The thread portion of the mold is formed by cutting the portion with a cutter having a screw shape. The thin screw portion is formed by inserting a cutter blade shallowly into the mold. Therefore, the basic shape of the thin screw is equal to the shape b in which the screw of the general part is pulled in a predetermined amount. However, if it is left as it is, the hem portion of the thin screw has a sharp shape, and defects are likely to occur in that portion, so the mold is secondarily processed so that the skirt portion becomes a curve d.

  The mold is opened on both sides after the glass bottle is molded to remove the product. In FIG. 1, the mouth mold for forming the mouth portion of the glass bottle opens from the joint C to the left and right in the direction of the arrow. At that time, if the screw 2 is horizontal, there is no problem, but since the screw is inclined, the screw and the mold interfere with each other, resulting in a so-called “unreasonable” state. FIG. 3 shows a state of mold opening when the joint portion is not a thin screw but the same screw as a general portion. When the mold is opened, the glass of the screw portion is inclined away in the direction of arrow B relative to the mold. And the interference part A where the glass of a screw part and a type | mold interfere arises. When the amount of interference at the interference portion is large, scratches called “chatter” occur at that portion, and the strength of the glass is significantly reduced.

  Conventionally, it has been believed that using a thin screw at the joint portion has an effect of reducing the amount of interference in mold opening. Therefore, the amount of interference at the time of mold opening was calculated for the general screw 2 and the conventional thin screw 3 shown in FIG. FIG. 3 shows the case of a general screw, and FIG. 4 shows the case of a thin screw. Surprisingly, the amount of interference was 0.075 mm, which was the same value for the general screw and the thin screw. That is, the conventional skin screw has no effect of reducing the amount of interference.

  The inventors have studied a thin screw shape that reduces the amount of interference in mold opening. FIG. 5 shows the shape of the thin screw 3 reached as a result. In the figure, a is a screw shape (cross-sectional shape) of a general part, and the screw height is 1.3 mm. b is a shape in which the screw height a is pulled 0.3 mm horizontally to a screw height of 1.0 mm. Two tangent lines c are drawn between the upper and lower mountain hems between the shapes a and b, and the contact point between each tangent line c and the shape a is p, and the contact point with the shape b is q. The cross-sectional shape of the thin screw 3 is a shape b between the two contacts q, a tangent line c between the contacts p and q, and a shape a on both sides of the two contacts p. (Shape shown by a solid line).

  FIG. 6 shows how the thin screw of the above embodiment is opened. In this case, the amount of interference between the screw portion glass and the mold is 0.035 mm, and the amount of interference is less than half of the conventional amount. Accordingly, it is possible to reduce the occurrence of chatter at the joint portion of the screw.

  In the case of molding a glass bottle, oil is applied to the inner surface of the mold in order to prevent friction between the mold and the glass and improve the separation of the glass mold. However, by applying oil to the mold, there is a problem that the outside of the molded glass bottle is soiled with oil, or oil enters the inside of the bottle to become filth, and oil-free molding is desired. Therefore, when an oil-free molding with the improved thin screw shape of FIG. 6 was tried, the screw joint portion of the mouth mold was worn significantly by rubbing against the glass.

  An object of the present invention is to further reduce the amount of interference between the screw part mold and the glass at the joint when the mold is opened, or to eliminate the interference at all.

  According to the present invention, as the cross section of the screw is moved away from the joint portion from the joint portion of the glass bottle mouth portion to both sides, the surface on the side that interferes with the glass at the time of mold opening gradually retracts inward. It is a glass bottle characterized by having a region formed in.

  The cross-sectional shape of the screw is formed so that the surface on the side that interferes with the glass gradually retracts inward as the mold opens as the distance from the joint portion increases. Less or no interference can be achieved, and the occurrence of chattering at the joints of the screw can be completely prevented, and wear of the mold part when oil-free molding is performed is prevented and durability is improved. It can be improved.

  In the present invention, the surface that interferes with the glass when the mold is opened is usually inclined so that the right side of the screw is higher, so that the upper side of the screw faces the right side of the joint. The left side is the lower surface of the screw. If the slope of the screw is opposite, it will be on the opposite side.

  When opening the mold, the area to be formed so that the surface that interferes with the glass gradually retracts to the inside varies depending on the bottle diameter, screw shape, thread height, etc. A central angle of 2 ° to 8 ° is preferred.

  Outside the region, it is desirable to gradually return the screw so that the cross-sectional shape of the screw becomes the same shape as the joint portion as the distance from the joint portion increases. By doing so, the change in the shape of the screw becomes inconspicuous.

  7 is a plan view of the vicinity of the joint of the mouth of the glass bottle 1 of the embodiment, FIG. 8 is an explanatory view of the screw shape of the AO, CO, and EO cross sections of FIG. 7, and FIG. FIG. 10 is an explanatory diagram of the screw shape of the D-O cross section of FIG. 7.

  In FIG. 7, O is the center of the mouth of the glass bottle 1, and the line C-O is a mouth-shaped seam line. A thin screw 3 (height 1.0 mm) smaller than the screw 2 (height 1.3 mm) in the general portion is formed in the vicinity of the joint. The screw shape of the general portion is indicated by a chain line in FIGS. The shape of the thin screw 3 is different between the joint portion and its both side portions. The screw shape of the joint portion (C-O cross section in FIG. 7) is shown by a solid line in FIG. The apex t has an arc curve with a radius of 0.9 mm, and the skirt s has an arc curve with a radius of 1 mm.

  From the joint portion to both sides, the cross-sectional shape of the screw is formed such that the surface on the side that interferes with the glass when the mold is opened gradually retracts inward as the distance from the joint portion increases. Since the screw is inclined so as to rise normally to the right shoulder, the left side (direction B in FIG. 7) from the joint (C in FIG. 7) is the lower side of the screw and the right side (direction D in FIG. 7). ) Is formed so that the upper side of the screw is retracted inside.

  The screw shape of the B-O cross section in FIG. 7 is indicated by a solid line in FIG. What is indicated by a dotted line in FIG. 8 is a screw shape at the joint (C). Thus, the screw shape in the B-O cross section is a shape in which the lower side is retracted inward than the screw shape at the joint. The shape of the upper half is the same as the shape at the joint. In the lower half, the apex has an arc curve with a radius of 0.7 mm, and the skirt has an arc curve with a radius of 1.3 mm. In this way, by reducing the radius of the arcuate curve at the top and increasing the radius of the arcuate curve at the skirt from the thread shape of the joint, a shape retracted inward can be realized.

  The screw shape between the C-O cross section and the B-O cross section gradually changes from the shape of FIG. 8 to the shape of FIG. 9. On the contrary, the screw shape from the B-O cross section to the A-O cross section gradually changes from the shape of FIG. 9 to the shape of FIG. 8, and the A-O cross section is the same as the screw shape at the joint. (FIG. 8). The angle (center angle) between C—O and B—O is 3 °, and the angle (center angle) between B—O and A—O is 6 °.

  The screw shape of the D-O cross section in FIG. 7 is indicated by a solid line in FIG. What is indicated by a dotted line in FIG. 10 is a screw shape at the joint (C). Thus, the screw shape in the D-O cross section is a shape in which the upper side is recessed inward than the screw shape at the joint. The screw shape in FIG. 10 is obtained by vertically inverting the screw shape in FIG.

  The screw shape between the C-O cross section and the D-O cross section gradually changes from the shape of FIG. 8 to the shape of FIG. In addition, the screw shape from the D-O cross section to the EO cross section, on the contrary, gradually changes from the shape of FIG. 10 to the shape of FIG. 8, and the same shape as the screw shape at the joint in the EO cross section. (FIG. 8). The angle (center angle) between C-O and D-O is 3 °, and the angle (center angle) between D-O and EO is 6 °.

  In this example, as a result of calculating the amount of interference between the mold of the joint thread portion and the glass at the time of mold opening, it was found that the amount of interference was 0 and no interference occurred.

  The screw portion of the forming die for forming the screw shape as in the above embodiment can be cut by, for example, a so-called three-dimensional NC cutting machine.

It is a schematic front view of a glass bottle. It is explanatory drawing of a thin screw. It is explanatory drawing of the mold opening at the time of using a joint as a screw of a general part. It is explanatory drawing of the mold opening at the time of using a thin screw of FIG. It is explanatory drawing of a thin screw. It is explanatory drawing of the mold opening at the time of using a thin screw of FIG. It is a top view near the joint of the opening part of the glass bottle 1 of an Example. It is explanatory drawing of the screw shape of the AO, CO, and EO cross section of FIG. It is explanatory drawing of the screw shape of the BO cross section of FIG. It is explanatory drawing of the screw shape of the D-O cross section of FIG.

Explanation of symbols

1 glass bottle 2 screw 3 thin screw

Claims (3)

  A region where the cross-sectional shape of the screw is formed so that the surface that interferes with the glass gradually retracts inward as the mold is opened as it moves away from the joint part from the joint part of the glass bottle part to both sides. A glass bottle characterized by having.   The glass bottle according to claim 1, wherein the region has a central angle of 2 ° to 8 ° on both sides of the joint line.   3. The glass bottle according to claim 1, wherein the cross-sectional shape of the screw gradually returns to the same shape as the joint portion as the distance from the joint portion increases outside the region.

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