Molten glass cutting apparatus

A molten glass cutting apparatus comprises a first support portion, a second support portion, a restriction portion and an applying portion. The first support portion supports a shear blade so as to be rotatable around a first axis extending in the width direction of the shear blade. The second support portion supports the shear blade so as to be rotatable around a second axis extending in the length direction of the shear blade. The restriction portion restricts rotation of the shear blade provided with the first support portion around the first axis so that inclined portions of a projecting portions of each of a pair of the shear blades face each other when a pair of the shear blades are separated. The applying portion applies an elastic force around the first axis for pressing a pair of the shear blades against each other to the shear blade provided with the first support portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on Japanese Patent Application No. 2021-087465 filed on May 25, 2021, and the patent is incorporated herein in its entirety.

TECHNICAL FIELD

The present invention relates to a molten glass cutting apparatus.

BACKGROUND ART

Conventionally, as described in Patent Literature 1, for example, a molten glass cutting apparatus including a pair of shear blades is known. In this apparatus, the molten glass falling from above is cut by a shearing force by cutting edges of a pair of shear blades. Gobs, which are pieces of cut molten glass, are used in the manufacture of glass products such as glass containers.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

In order to cut the molten glass satisfactorily, it is necessary to prevent a large gap from being formed between the cutting edge sides of a pair of shear blades in a state in which the tip parts of a pair of the shear blades overlap. For this purpose, a pair of the shear blades need to overlap while pressing each other, and the configuration to be described below is used.

In each of a pair of the shear blades, projecting portions projecting in the length direction of the shear blade are formed on the cutting edge side and on both sides in the width direction. The projecting portions of each of a pair of the shear blades are inclined in the direction opposite to the side where the tip parts overlap so as to serve as a guide when the tip parts of a pair of the shear blades overlap.

The base end part of one of a pair of the shear blades is attached to a first base portion. The other base end part of the other one of a pair of the shear blades is attached to the second base portion so as to be slightly offset in the vertical direction with respect to the shear blade attached to the first base portion. In a state in which a pair of the shear blades are separated from each other, the inclined portions of the projecting portions of a pair of the shear blades face each other.

When the first base portion and the second base portion are relatively moved toward each other, the inclined portions of the projecting portions of a pair of the shear blades come into contact with each other. In this case, since each projecting portion is inclined in the direction opposite to the side where the tip parts of a pair of the shear blades overlap, one of a pair of the shear blades rides on the upper surface of the other. In this case, a pair of the shear blades are in a state of being elastically deformed. As a result, a pair of the shear blades can be in a state of pressing each other while keeping the pressing force utilizing the elasticity of the shear blades within a proper range.

However, the shear blade may get distorted. For example, when the shear blade is manufactured by pressing, quenching of the pressed shear blade may generate a warp in the length direction and the width direction of the shear blade, causing the shear blade to get distorted. When the shear blade gets distorted, the pressing force utilizing the elasticity of the shear blades may deviate from the proper range. If the shear blade is used with the pressing force deviated from the proper range, the quality of the gob to be used for manufacturing the glass product may deteriorate and the life of the shear blade may shorten.

In addition, there is also a problem to be described below. When the shear blades wear due to use of the shear blades, the force of a pair of the shear blades pressing each other drops below the lower limit of the proper range, and the gap on the cutting edge side may increase. In this case, the molten glass cannot be cut satisfactorily, the quality of the gobs may deteriorate, and the life of each shear blade may shorten. In order to prevent the quality of the gobs from deteriorating and the life of each shear blade from shortening, it is necessary to keep the pressing force utilizing the elasticity of the shear blades within a proper range. For this reason, it is necessary to adjust the positional relationship of a pair of the shear blades in the vertical direction. However, this adjustment work is burdensome for the operator.

As described above, the cutting method that largely depends on the pressing force utilizing the elasticity of the shear blades can increase the burden on the operator. Therefore, there is still room for improvement in the technique for cutting molten glass.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a molten glass cutting apparatus capable of preventing quality of gobs from deteriorating and lives of shear blades from shortening while reducing a burden on an operator.

Solution to Problem

The present invention is a molten glass cutting apparatus, including:a pair of shear blades;base portions each provided for a base end part of each of a pair of the shear blades;wherein a pair of the base portions are relatively moved toward each other so that tip parts of a pair of the shear blades overlap, and a shearing force by cutting edges of a pair of the shear blades cuts molten glass falling from above,each of a pair of the shear blades having projecting portions formed therein on both sides in a width direction and on a cutting edge side, the projecting portions each projecting in a length direction of the shear blade,the projecting portions of each of a pair of the shear blades being inclined in a direction opposite to a side where the tip parts overlap so that each projecting portions serves as a guide when the tip parts of a pair of the shear blades overlap by the relative movement toward each other;a first support portion provided at the base end part of one of a pair of the shear blades, the first support portion supporting the shear blade with respect to the base portion so as to be rotatable around a first axis extending in the width direction of the shear blade;a second support portion provided at the base end part of one of a pair of the shear blades, the second support portion supporting the shear blade with respect to the base portion so as to be rotatable around a second axis extending in the length direction of the shear blade;a restriction portion that restricts rotation of the shear blade provided with the first support portion around the first axis so that inclined portions of the projecting portions of each of a pair of the shear blades face each other when a pair of the shear blades are separated; andan applying portion that applies an elastic force around the first axis for pressing a pair of the shear blades against each other to the shear blade provided with the first support portion.

In the present invention, one of the base end parts of a pair of the shear blades is provided with a first support portion that rotatably supports the shear blade with respect to the base portion around the first axis extending in the width direction of the shear blade. In addition, the one of the base end parts of a pair of the shear blades is provided with a second support portion that rotatably supports the shear blade with respect to the base portion around the second axis extending in the length direction of the shear blade.

When a pair of the shear blades are separated from each other, the rotation of the shear blade provided with the first support portion around the first axis is restricted by the restriction portion so that the inclined portions of the projecting portions of a pair of the shear blades face each other. Therefore, when a pair of the base portions are relatively moved toward each other, the inclined portions of the projecting portions of a pair of the shear blades can be brought into contact with each other.

After that, while the shear blades provided with the first support portions rotate around the first axis, the tip parts of a pair of the shear blades overlap. In this overlapping state, the applying portions each apply an elastic force around the first axis for pressing a pair of the shear blades against each other to the shear blade provided with the first support portion. Therefore, for example, if there is a warp in the length direction of the shear blades, the force with which a pair of the shear blades press against each other can be within a proper range without being largely dependent on the pressing force utilizing the elasticity of the shear blades.

In addition, in a state in which the tip parts of a pair of the shear blades overlap, the shear blade provided with the second support portion is pressed by the shear blade provided with the first support portion to rotate around the second axis so as to place the respective cutting edge sides of a pair of shear blades along each other. Therefore, for example, if there is a warp in the width direction of the shear blades, the force with which a pair of the shear blades press against each other can be within a proper range without being largely dependent on the pressing force utilizing the elasticity of the shear blades.

In addition, according to the present invention, since the above-mentioned force is applied to the shear blade by the applying portion, the force with which the pair of shear blades press against each other can be maintained within a proper range if the shear blades wear.

According to the present invention described above, it is possible to reduce the burden on the operator required for the shear blade installation work and adjustment, and at the same time to prevent the quality of the gob from deteriorating and the life of the shear blade from shortening.

DESCRIPTION OF EMBODIMENTS

First Embodiment

A first embodiment embodying a molten glass cutting apparatus of the present invention is to be described below with reference to drawings. The molten glass cutting apparatus constitutes a glass container manufacturing apparatus10shown inFIG.1. Note that some configurations are omitted to be shown in some drawings for convenience.

As shown inFIG.1, the manufacturing apparatus10includes a spout11and a spout case12that holds the spout11. The spout11stores molten glass Gm supplied from a glass melting furnace (not shown).

The manufacturing apparatus10includes a clay tube13and a tube drive unit14. The clay tube13has a tubular shape. The lower end of the clay tube13is immersed in the molten glass Gm in the spout11. The clay tube13can be rotated around a central axis extending in the vertical direction by the tube drive unit14. Thus, the molten glass Gm in the spout11is agitated. In addition, the vertical position of the clay tube13can be adjusted by the tube drive unit14. The lower end part of the clay tube13and the bottom surface of the spout11form a passage for the molten glass Gm. Therefore, vertically changing the position of the clay tube13adjusts the amount of molten glass Gm flowing out to the outflow hole11aside formed at the bottom part of the spout11. A circular orifice17is formed at the bottom part of the spout11.

The manufacturing apparatus10includes a plunger15and a plunger drive unit16. The plunger drive unit16enables the plunger15to perform reciprocating motion in the vertical direction. When the plunger15is lowered to cause the tip part of the plunger15to enter the outflow hole11a, the molten glass Gm is extruded to the outside of the spout11through the orifice17. This causes the molten glass Gm to hang down in a columnar shape. On the other hand, when the plunger15is raised to separate the tip part of the plunger15from the outflow hole11a, the hanging molten glass Gm is sucked into the orifice17.

Note thatFIG.1shows an example in which the manufacturing apparatus10includes one plunger15, but the present invention is not limited to this, and the manufacturing apparatus10may include a plurality of plungers15. In this case, the same number of orifices17as the number of plungers15only need to be formed at the bottom part of the spout11.

The manufacturing apparatus10includes a molten glass cutting apparatus. The molten glass cutting apparatus includes a first shear blade30, a second shear blade40, and a blade drive unit18. The first shear blade30and the second shear blade40are arranged below the orifice17. The first shear blade30is arranged so as to face the second shear blade40in the horizontal direction. A servomotor or the like provided in the blade drive unit18enables the first shear blade30and the second shear blade40to perform reciprocating motion in the horizontal direction in synchronization with the vertical motion of the plunger15. The molten glass Gm flowing down from the orifice17is cut by the shearing force between the cutting edge of the first shear blade30and the cutting edge of the second shear blade40. The cut molten glass Gm becomes a rod-shaped gob Gb and falls by gravity.

The molten glass cutting apparatus includes a supply unit19. The supply unit19supplies cooling water for cooling the first and second shear blades30,40and the like to the first and second shear blades30,40and the like.

The manufacturing apparatus10includes a funnel20, a distribution apparatus21, and a plurality of molds22. The funnel20is arranged below the orifice17and has a funnel shape. The funnel20guides the fallen gob Gb to the distribution apparatus21. The distribution apparatus21sequentially supplies the gobs Gb guided via the funnel20to each of the plurality of molds22via a gutter (not shown). In each mold22, glass containers such as bottles are formed using the gobs Gb.

The manufacturing apparatus10includes a controller23as a control unit. The controller23includes a microcomputer, a memory, and the like, and controls the operations of the tube drive unit14, the plunger drive unit16, the blade drive unit18, the supply unit19, and the distribution apparatus21.

Subsequently, the molten glass cutting apparatus is to be described in detail with reference toFIGS.2to8.

The first shear blade30is a member made of a plate material. The first shear blade30is made of, for example, ceramic, titanium, or tungsten.

As shown inFIG.4, the cross-sectional shape of the tip part of the first shear blade30in the length direction is such that it projects upward. This forms a first blade surface31b, which is an inclined surface, at the tip part of the first shear blade30. The tip of the first blade surface31bis the first cutting edge31a. In the planar view of the first shear blade30, the contour of the first cutting edge31aretracts to the base end side of the first shear blade30toward the center in the width direction. As a result, in this embodiment, the contour of the first cutting edge31ais U-shaped in the planar view of the first shear blade30.

In the first shear blade30, there are formed first projecting portions32projecting in the length direction of the first shear blade30on both sides in the width direction on the side of the first cutting edge31a. Each first projecting portion32inclines obliquely downward. The width direction dimensions of the first projecting portion32decrease toward the tip in the length direction of the first shear blade30.

The base end part of the first shear blade30is fixed to the first base portion50. Specifically, the first shear blade30has formed therein a cutout33extending from the end on the base end side in the length direction toward the tip part side. The first base portion50has formed therein a bolt hole52through which a bolt51is inserted. In this embodiment, a plurality (two) of bolt holes52are formed in line in the length direction of the first shear blade30. With the first shear blade30interposed between the seat surface of the bolt51and the first base portion50, the bolt51is inserted into the cutout33and the bolt hole52, and the bolt51is tightened. As a result, the first shear blade30is fixed to the first base portion50.

The second shear blade40is a member made of a plate material. The second shear blade40is made of, for example, ceramic, titanium, or tungsten. In this embodiment, the second shear blade40is made of the same material as the first shear blade30. Note that the second shear blade40may be made of a material different from that of the first shear blade30.

As shown inFIG.4, the cross-sectional shape of the tip part of the second shear blade40in the length direction is such that it projects downward. This forms a second blade surface41b, which is an inclined surface, at the tip part of the second shear blade40. The tip of the second blade surface41bis the second cutting edge41a. In the planar view of the second shear blade40, the contour of the second cutting edge41aretracts to the base end side of the second shear blade40toward the center in the width direction. As a result, in this embodiment, the contour of the second cutting edge41ais U-shaped in the planar view of the second shear blade40. The contours of the second cutting edge41aand the first cutting edge31amay be, for example, V-shaped instead of U-shaped.

In the second shear blade40, there are formed second projecting portions42projecting in the length direction of the second shear blade40on both sides in the width direction on the side of the second cutting edge41a. The second projecting portion42is inclined diagonally upward. The width direction dimensions of the second projecting portion42decrease toward the tip in the length direction of the second shear blade43.

Each of the first shear blade30and the second shear blade40has a symmetrical shape with respect to the center in the width direction. Therefore, the contour of the first cutting edge31ais symmetrical with respect to the center in the width direction. The contour of the second cutting edge41ais also symmetrical with respect to the center in the width direction. In this embodiment, the first shear blade30has the same shape as the second shear blade40.

The cutting apparatus includes a mounting portion60. The mounting portion60includes a blade mounting portion61. The upper surface of the blade mounting portion61is a flat surface, and the base end part of the second shear blade40is fixed to the flat surface. Specifically, a blade mounting portion61has formed therein a bolt hole64through which the bolt63is inserted. In this embodiment, a plurality (two) of bolt holes64are formed in line in the length direction of the second shear blade40. On the other hand, the second shear blade40has formed therein a cutout43extending from the end on the base end side in the length direction toward the tip part side. With the second shear blade40interposed between the seat surface of the bolt63and the blade mounting portion61, the bolt63is inserted into the cutout43and the bolt hole64, and the bolt63is tightened. As a result, the second shear blade40is fixed to the blade mounting portion61.

The mounting portion60includes a support mounting portion62. The support mounting portion62is provided on the side of the blade mounting portion61opposite to the second shear blade40in the length direction of the second shear blade40.

The cutting apparatus includes a second base portion70, a shaft support portion71, and a rotating member72. The shaft support portion71is fixed to the second base portion70and extends upward from the second base portion70. A pair of shaft support portions71are provided, and the shaft support portions71are arranged apart from each other in the width direction of the second shear blade40.

The rotating member72includes a columnar first rotating shaft72aand a second rotating shaft72bextending from the center of the first rotating shaft72ain the length direction to a direction orthogonal to the axial direction of the first rotating shaft72a. Each shaft support portion71has formed therein a hole extending in the width direction of the second shear blade40. Each of both ends of the first rotating shaft72ais inserted into the hole formed in each shaft support portion71. As a result, the rotating member72is rotatably supported by the second base portion70around the first axis extending in the width direction of the second shear blade40. The central axis of the first rotating shaft72aaligns with the first axis.

As shown inFIGS.4and6, a pair of concave portions62athat are recessed in a semicircular shape are formed on the lower side of the support mounting portion62. The receiving portions73fixed to the lower side of the support mounting portion62have formed therein concave portions73athat are recessed in a semicircular shape. The concave portions62aof the support mounting portion62and the concave portions73aof the receiving portions73form bearing holes through which opposite ends of the second rotating shaft72bare inserted. On the lower side of the support mounting portion62, the space between a pair of the concave portions62aarranged in the length direction is recessed above the concave portions62a. This is to prevent the rotating member72from interfering with the lower surface of the support mounting portion62when the rotating member72rotates around a second axis.

The support mounting portion62and the receiving portion73described above allow the rotating member72to rotate around the second axis extending in the length direction of the second shear blade40. As a result, the second shear blade40is rotatably supported around the second axis with respect to the second base portion70. The central axis of the second rotating shaft72baligns with the second axis. Note that, in this embodiment, the mounting portion60, the shaft support portion71, and the first and second rotating shafts72aand72bcorrespond to a “first and second support portions”. In addition, the shaft support portion71and the first and second rotating shafts72aand72bcorrespond to a “rotating portion”.

The cutting apparatus includes a first upper stopper portion80aand a first lower stopper portion80b. The first upper stopper portion80ais provided on the blade mounting portion61at its center of the lower surface of in the width direction of the second shear blade40. The first upper stopper portion80aprojects downward from the lower surface of the blade mounting portion61. In this embodiment, the first upper stopper portion80ais formed from a bolt.

The first lower stopper portion80bis provided on the second base portion70at a position thereof facing the first upper stopper portion80ain the vertical direction. The first lower stopper portion80bextends upward from the second base portion70. In this embodiment, the first lower stopper portion80bis formed from a bolt. Note that, in this embodiment, the first upper stopper portion80aand the first lower stopper portion80bcorrespond to a “first restriction portion”.

When the mounting portion60rotates in a specific direction around the first axis, the first upper stopper portion80acomes into contact with the first lower stopper portion80b, restricting the rotation of the mounting portion60in a specific direction around the first axis. In this case, as shown inFIG.7, the second shear blade40is in a forward leaning posture, and the second projecting portion42is in a state of facing the first projecting portion32in the horizontal direction.

The mounting portion60includes an extending portion65. The extending portion65is provided on the side of the support mounting portion62opposite to the blade mounting portion61in the length direction of the second shear blade40.

As shown inFIGS.4and6, the cutting apparatus includes a second upper stopper portion81aand a second lower stopper portion81b. The second upper stopper portion81ais provided on the lower surface of the extending portion65at its center in the width direction of the second shear blade40. The second upper stopper portion81aprojects downward from the lower surface of the extending portion65. In this embodiment, the second upper stopper portion81ais formed from a bolt.

The second lower stopper portion81bis provided on the second base portion70at a position facing the second upper stopper portion81ain the vertical direction. The second lower stopper portion81bextends upward from the second base portion70. In this embodiment, the second lower stopper portion81bis formed from a bolt.

When the mounting portion60rotates in the direction opposite to the specific direction around the first axis, the second upper stopper portion81acomes into contact with the second lower stopper portion81b, restricting the rotation of the mounting portion60in the direction opposite to the specific direction around the first axis. In this case, as shown inFIG.4, the second shear blade40is in the horizontal state. In this embodiment, the second upper stopper portion81aand the second lower stopper portion81bcorrespond to a “second restriction portion”.

As shown inFIG.6, the cutting apparatus includes a first adjusting bolt82a, a second adjusting bolt82b, a first spring83a, and a second spring83b. In this embodiment, the first spring83aand the second spring83bare compression coil springs, and the free length and the spring constant are set to the same. In this embodiment, the first and second springs83aand83bcorrespond to “first and second applying portions”.

In a part of the extending portion65that is offset to one side in the width direction by a predetermined distance with respect to the center of the second shear blade40in the width direction, there is formed a through hole penetrating the extending portion65in the thickness direction. The first adjusting bolt82ais inserted into the through hole, and the first adjusting bolt82ais fixed with a nut. The head of the first adjusting bolt82aprojects downward from the lower surface of the extending portion65.

In a part of the extending portion65that is offset to the other side in the width direction by the above predetermined distance with respect to the center of the second shear blade40in the width direction, there is formed a through hole penetrating the extending portion65in the thickness direction. The second adjusting bolt82bis inserted into the through hole, and the second adjusting bolt82bis fixed with a nut. The head of the second adjusting bolt82bprojects downward from the lower surface of the extending portion65.

A first groove portion74aextending downward from the upper surface of the second base portion70is formed in a part of the second base portion70that faces the head of the first adjustment bolt82ain the vertical direction. A projection that restricts the horizontal movement of one end of the first spring83ais formed on the bottom surface of the first groove portion74a.

A second groove portion74bextending downward from the upper surface of the second base portion70is formed in a part of the second base portion70that faces the head of the second adjusting bolt82bin the vertical direction. A projection that restricts horizontal movement of one end of the second spring83bis formed on the bottom surface of the second groove portion74b.

The first adjusting bolt82ais a flange bolt, the flange of the first adjusting bolt82ais the seat surface of the first end of the first spring83a, and the head of the first adjusting bolt82aserves to restrict the horizontal movement of the first end of the first spring83a. The bottom surface of the first groove portion74ais the seat surface of the second end of the first spring83a. The second adjusting bolt82bis a flange bolt, the flange of the second adjusting bolt82bis the seat surface of the first end of the second spring83b, and the head of the second adjusting bolt82bserves to restrict the horizontal movement of the first end of the second spring83b. The bottom surface of the second groove portion74bis the seat surface of the second end of the second spring83b.

In a state in which the first upper stopper portion80ais in contact with the first lower stopper portion80b, the first ends of the first and second springs83aand83hare in contact with the flanges of the first; and second adjusting bolts82aand82b, and the second ends of the first and second springs83aand83bare in contact with the bottom surfaces of the first and second groove portions74aand74b. As a result, as the second shear blade40starts rotating around the first axis in the direction opposite to the specific direction from the state in which the first upper stopper portion83ais in contact with the first lower stopper portion80b, an elastic force for rotating the second shear blade40in the specific direction is quickly applied to the mounting portion60. Here, in a state in which the first upper stopper portion80ais in contact with the first lower stopper portion80b, the first and second springs83aand83bare in a compressed state. As a result, it is possible to increase the elastic force for rotating the second shear blade40in a specific direction.

When the second upper stopper portion81ais in contact with the second lower stopper portion81band the mounting portion60is in the horizontal state, the distance from the flange of the first adjusting bolt82ato the bottom surface of the first groove portion74ais equal to the distance from the flange of the second adjusting bolt82bto the bottom surface of the second groove portion74b. In other words, when the mounting portion60is not tilted in the width direction, the elastic forces applied to the mounting portions60by the first and second springs83aand83bare equal. Therefore, when the mounting portion60is tilted in the width direction, elastic force around the second axis for eliminating the tilt is applied to the mounting portion60from the first and second springs83aand83b.

Subsequently, description is to be made on operation of the first shear blade30and the second shear blade40when cutting the molten glass Gm.

When the second shear blade40and the first shear blade30are separated from each other in the horizontal direction as shown inFIG.9A, the rotation of the mounting portion60around the first axis is restricted by the first upper stopper portion80aand the first lower stopper portion80bso that the inclined portion of the first projecting portion32faces the inclined portion of the second projecting portion42in the horizontal direction as shown inFIG.7. Therefore, moving the first base portion50and the second base portion70toward each other can bring the inclined portions of the first and second projecting portions32and42into contact with each other. The first and second projecting portions32and42serve as a guide when the tip parts of the first and second shear blades30and40overlap.

Here, in a state in which the rotation of the mounting portion60around the first axis is restricted by the first upper stopper portion80aand the first lower stopper portion80b, the first spring833aand the second spring83bare in a compressed state. Therefore, when the first base portion50and the second base portion70are brought close to each other, the second shear blade40can be maintained in a forward leaning posture. As a result, when the first base portion50and the second base portion70are brought close to each other, it is possible to prevent the second shear blade40from rotating in a specific direction around the first axis if some external force acts on the second shear blade40.

After that, as the first base portion50and the second base portion70are brought closer to each other, the mounting portion60to which the second shear blade40is fixed rotates around the first axis, so that the lower surface of the second shear blade40and the upper surface of the first shear blade30are in contact with each other while the tip part of the first shear blade30and the tip part of the second shear blade40overlap as shown inFIGS.9B and10. In this case, since the first spring83aand the second spring83bare further compressed, a force for rotating the mounting portion60around the first axis in the direction opposite to the specific direction is applied to the mounting portion60from the first spring83aand the second spring83b. This causes the second shear blade40to press the first shear blade30. Therefore, if the first and second shear blades30and40warp in the length direction, the force for pressing the second shear blade40against the first shear blade30can be within a proper range without being largely dependent on the pressing force utilizing the elasticity of the shear blades.

On the other hand, when the first and second shear blades30and40warp in the width direction and the tip part of the first shear blade30and the tip part of the second shear blade40overlap, the mounting portion60rotates around the second axis, and the second shear blade40tilts in the width direction as shown inFIG.8BorFIG.8C. In this case, elastic force around the second axis for eliminating the tilt is applied to the mounting portion60from the first and second springs83aand83bin this embodiment. Therefore, if the first and second shear blades30and40warp in the width direction, the sides of the first and second cutting edges31aand41acan be placed along each other without being largely dependent on the pressing force utilizing the elasticity of the shear blades. As a result, the force for pressing the second shear blade40against the first shear blade30can be made within a proper range.

In addition, according to this embodiment, if the first and second shear blades30and40wear, the force with which the first and second shear blades30and40press each other can be maintained within a proper range.

According to this embodiment described above, it is possible at the same time: to reduce the burden on the operator required for installation work and adjustment of the first and second shear blades30and40; and to prevent the quality of the gob from deteriorating and the life of the first and second shear blades30and40from being shortened.

In order to reduce the wear of the first and second shear blades30and40, it is preferable that the hardness of the first and second shear blades30and40be high. However, if the hardness is high, it is difficult to keep the pressing force utilizing the elasticity of the shear blades within a proper range. In this respect, according to this embodiment, if a shear blade having high hardness is used, the pressing force utilizing the elasticity of the shear blades could be kept within a proper range.

In this embodiment, the first and second springs83aand83bcan apply: both the force for rotating the mounting portion60around the first axis so as to press the second shear blade40against the first shear blade30; and the force for rotating the mounting portion60around the second axis so as to eliminate the tilt of the second shear blade40in the width direction. Thus, integrating the configurations for applying the pressing force on the second shear blade40side, in the first and second shear blades30and40, can simplify the configuration of the molten glass cutting apparatus.

The inclined portion of the second projecting portion42and the inclined portion of the first projecting portion32come into contact with each other, so that the first shear blade30pushes up the second shear blade40, rotating the second shear blade40in a specific direction around the first axis. In this case, the gap between the second shear blade40and the first shear blade30may increase, so that molten glass Gm may enter the gap between the second shear blade40and the first shear blade30when the molten glass Gm is cut. In this case, for example, the molten glass Gm that has entered rapidly cools and harden. As a result, the solidified glass may be broken due to the relative movement of the second shear blade40and the first shear blade30. When the glass is broken, the broken glass pieces may be scattered around, or the scattered glass pieces may be mixed in the gob Gb.

In this respect, according to this embodiment, when the tip parts of the first and second shear blades30and40overlap, the rotation of the second shear blade40around the first axis is restricted by the second upper stopper portion81aand the second lower stopper portion81bso that the tip parts of the first and second shear blades30and40do not separate in the vertical direction. Therefore, it is possible to prevent a gap from being generated between the second shear blade40and the first shear blade30due to the contact between the inclined portions of the first and second projecting portions32and42.

The first spring83aand the second spring83bare in a compressed state when the first upper stopper portion80ais in contact with the first lower stopper portion80b. Therefore, as the second shear blade40starts rotating around the first axis in the direction opposite to the specific direction, the elastic force of the first and second springs83aand83bfor rotating the second shear blade40in a specific direction can be increased. As a result, it is possible to preferably prevent a gap from being generated between the second shear blade40and the first shear blade30due to the contact between the inclined portions of the first and second projecting portions32and42.

A configuration including a mounting portion60for applying a pressing force, a rotating member72, and springs83aand83bis applied to the second shear blade40side. In this case, the own weights of the second shear blade40, the blade mounting portion61, and the like can be used as a part of the pressing force against the first shear blade30. As a result, it is possible to more preferably prevent a gap from being generated between the second shear blade40and the first shear blade30due to the contact between the inclined portions of the first and second projecting portions32and42.

Second Embodiment

A second embodiment is to be described below with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, a spherical plain bearing is used as a configuration for rotating the mounting portion around the first and second axes.

The configuration of the second shear blade40side of the cutting apparatus is to be described with reference toFIGS.11to15. Note that, inFIGS.11to15, some of the same configurations as, or the corresponding configurations to those described in the first embodiment are designated by the same reference numerals for convenience. In addition, some configurations are omitted to be shown in some drawings for convenience.

The cutting apparatus includes a bearing90and a support shaft93. The bearing90is a spherical plain bearing, and includes an inner ring91having a spherical outer peripheral surface and an outer ring92having a concave surface corresponding to the outer peripheral surface thereof. The outer ring92has an annular shape.

A bearing hole is formed in the inner ring91. The support shaft.93has a small diameter portion93aon the first end side in the axial direction and a large diameter portion93bon the portion adjacent to the small diameter portion93ain the axial direction. The outer diameter dimension of the large diameter portion93bis larger than the outer diameter dimension of the small diameter portion93a.

A small diameter portion93ais inserted into the bearing hole of the inner ring91, and the small diameter portion93ais in contact with the plate surface of the disk portion94having a larger outer diameter dimension than the small diameter portion93a. A through hole is formed in the central part of the disk portion94, and a bolt hole is formed in the first end of the support shaft93. In a state in which the small diameter portion93aand the inner ring91are in contact with the disk portion94, the bolt95is inserted into the through hole of the disk portion94and the bolt hole of the support shaft93, and the bolt95is tightened. As a result, the bearing90is fixed to the support shaft93.

A bolt hole is formed on the second end side of the support shaft93in the axial direction. A through hole is formed in the second base portion70. The bolt96is inserted into the through hole of the second base portion70and the bolt hole of the support shaft93, and the bolt96is tightened. As a result, the support shaft93is fixed to the second base portion70. As a result, the bearing90is fixed to the second base portion73.

The lower surface side of the support mounting portion62, which constitutes the mounting portion60, is a recess, and the recess serves as a housing space for the bearing90. The outer ring92is fixed to the peripheral wall portion62bon the lower surface side of the support mounting portion62. An annular lid portion66that covers the bearing90is fixed to the lower end of the support mounting portion62. A through hole into which the support shaft93is inserted is formed in the central part of the lid portion66.

The inner diameter side of the lid portion66and the large diameter portion93bof the support shaft93are separated from each other. A disk-shaped seal member67is attached to the large diameter portion93b. The seal member67is made of a material that is easily deformed, and is, for example, a felt seal. The outer edge of the seal member67is in contact with the lid portion66. The seal member67prevents foreign matter from the outside or cooling water from the supply unit19from entering the housing space of the bearing93partitioned by the support mounting portion62and the lid portion66, while allowing the rotational displacement of the mounting portion60with respect to the support shaft93. Preventing foreign matter or cooling water from entering can prevent the malfunction of the bearing90.

The cutting apparatus includes shaft support portions100and pins101. The shaft support portions100are fixed to the second base portion70and extend upward from the second base portion770. A pair of shaft support portions100are provided, and each shaft support portion100is arranged so as to be separated from each other in the width direction of the second shear blade40. The shaft support portions100each have formed therein a guide groove100aextending downward from the upper end. The lower end of the guide groove100ahas an arc shape.

Through holes62care respectively formed at parts of the peripheral wall portion62bof the support mounting portion62, which parts face each other in the width direction. A first end of each pin101is fixed to each of the parts of the outer ring92that face each other in the direction orthogonal to the axial direction. A second end side of each pin101is supported by each of the guide grooves100athrough the through hole62c. The guide groove100arestricts the movement of the pin101in the length direction of the second shear blade40, while allowing the pin101to move in the vertical direction and to tilt in the width direction. Therefore, the mounting portion60is rotatably supported by the second base portion70around the first axis and around the second axis. In this embodiment, the bearing90and the support shaft93correspond to a “rotating portion”.

According to this embodiment described above, similarly to the first embodiment, if the first and second shear blades30and40warp in the length direction, the force for pressing the second shear blade40against the first shear blade30can be within a proper range without being largely dependent on the pressing force utilizing the elasticity of the shear blades.

When the first and second shear blades30and40warp in the width direction and the tip parts of the first and second shear blades30and40overlap, the mounting portion60rotates around the second axis and the second shear blade surface41tilts in the width direction as shown inFIG.13BorFIG.13C. Even in this case, according to this embodiment, a force for rotating the mounting portion60around the second axis so as to eliminate the tilt is applied to the mounting portion60from the first and second springs83aand83b, similarly to the first embodiment. Therefore, if the first and second shear blades30and40warp in the width direction, the force for pressing the second shear blade40against the first shear blade30can be within a proper range without being largely dependent on the pressing force utilizing the elasticity of the shear blades.

Third Embodiment

A third embodiment is to be described below with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, the number of springs provided in the configuration on the second shear blade40side of the cutting apparatus is changed from two to one.

The configuration of the second shear blade40side of the cutting apparatus is to be described with reference toFIGS.16to18. Note that, inFIGS.16to18, some of the same configurations as, or the corresponding configurations to those described in the first embodiment are designated by the same reference numerals for convenience. In addition, some configurations are omitted to be shown in some drawings for convenience.

The cutting apparatus includes a second upper stopper portion181aand a second lower stopper portion181b. The second upper stopper portions181aare provided on parts of the lower surface of the extending portion65, which parts are offset to the opposite sides to each other in the width direction by a predetermined distance with respect to the center of the second shear blade40in the width direction. The second upper stopper portion181aprojects downward from the lower surface of the extending portion65. In this embodiment, the second upper stopper portions181aare formed from bolts.

The second lower stopper portions181bare provided at positions of the second base portion70that face the second upper stopper portions181ain the vertical direction. The second lower stopper portion181bextends upward from the second base portion70. In this embodiment, the second lower stopper portions181bare formed from bolts.

When the mounting portion60rotates in the specific direction around the first axis extending in the width direction of the second shear blade40, the first upper stopper portion80acomes into contact with the first lower stopper portion80b. On the other hand, when the mounting portion60rotates in the direction opposite to the specific direction around the first axis, the second upper stopper portions181acome into contact with the second lower stopper portions181b, restricting the rotation of the mounting portion60in the direction opposite to the specific direction around the first axis. In this embodiment, the second upper stopper portion181aand the second lower stopper portion181bcorrespond to a “second restriction portion”.

Incidentally, in a state in which each second upper stopper portion181ais in contact with each second lower stopper portion181b, the rotation of the mounting portion60is restricted around the second axis extending in the length direction of the second shear blade40. Therefore, the contact position of the second lower stopper portion181bwith respect to the second upper stopper portion181aonly needs to be adjusted in the vertical direction to allow the mounting portion60to rotate around the second axis when the tip part of the first shear blade30and the tip part of the second shear blade40overlap.

In the second rotating shaft72b, the side opposite to the second shear blade40in the axial direction is a contact portion74extending in the axial direction opposite to the second shear blade40. The lower surface of the contact portion74is a flat surface.

The cutting apparatus includes a spring183and a spring receiving portion175. In this embodiment, the spring183is a compression coil spring. In this embodiment, the spring183and the spring receiving portion175correspond to a “applying portion”.

A groove portion174extending downward from the upper surface of the second base portion70is formed at the center of the second base portion70in the width direction of the second shear blade40. A projection that restricts the horizontal movement of the lower end of the spring183is formed on the bottom surface of the groove portion174.

The spring receiving portion175has formed therein a seat surface175awith which the upper end of the spring183is in contact. A projection for restricting the horizontal movement of the upper end of the spring183is formed on the inside part of the seat surface175aof the spring receiving portion175. The upper tip part of the spring receiving portion175is a convex portion175b, and the convex portion175bhas a conical shape. The convex portion175bis in contact with the concave portion74aformed in the center in the width direction of the lower surface of the contact portion74. The outer diameter dimension of the convex portion175bis smaller than the outer diameter dimension of the spring183.

In a state in which the first upper stopper portion80ais in contact with the first lower stopper portion80b, the convex portion175bof the spring receiving portion175is in contact with the concave portion74aof the contact portion74. As a result, as the second shear blade40starts rotating around the first axis in the direction opposite to the specific direction from the state in which the first upper stopper portion83ais in contact with the first lower stopper portion80b, an elastic force for rotating the second shear blade40in the specific direction is quickly applied to the mounting portion60. In addition, the spring183is in a compressed state in a state in which the first upper stopper portion80ais in contact with the first lower stopper portion80b. As a result, it is possible to increase the elastic force for rotating the second shear blade40in a specific direction.

Subsequently, description is to be made on operation of the first shear blade30and the second shear blade40when cutting the molten glass Gm. The spring183is in a compressed state in a state in which the rotation of the mounting portion60around the first axis is restricted by the first upper stopper portion80aand the first lower stopper portion80b. Therefore, when the first base portion50and the second base portion70are brought close to each other, the second shear blade40can be maintained in a forward leaning posture.

After that, as the first base portion50and the second base portion70come closer to each other, the mounting portion60to which the second shear blade40is fixed rotates around the first axis, so that the lower surface of the second shear blade40and the upper surface of the first shear blade30are in contact with each other while the tip part of the first shear blade30and the tip part of the second shear blade40overlap. In this case, since the spring183is further compressed, a force for rotating the mounting portion60around the first axis in the direction opposite to the specific direction is applied to the mounting portion60from the spring183. This causes the second shear blade40to press the first shear blade30. Therefore, if the first and second shear blades30and40warp in the length direction, the force for pressing the second shear blade40against the first shear blade30can be within a proper range without being largely dependent on the pressing force utilizing the elasticity of the shear blades.

On the other hand, when the first and second shear blades30and40warp in the width direction and the tip part of the first shear blade30and the tip part of the second shear blade40overlap, the mounting portion60rotates around the second axis, and the second shear blade40tilts in the width direction. Therefore, if the first and second shear blades30and40warp in the width direction, the sides of the first and second cutting edges31aand41acan be placed along each other without being largely dependent on the pressing force utilizing the elasticity of the shear blades.

The convex portion175bof the spring receiving portion175is in contact with the concave portion74aformed in the center in the width direction of the lower surface of the contact portion74. Therefore, when the mounting portion60rotates around the second axis, it is possible to prevent the convex portion175bof the spring receiving portion175from being displaced from the center in the width direction of the lower surface of the contact portion74. As a result, it is possible to prevent the spring183from bending, so that it is possible to prevent the load of the spring183from decreasing and the life of the spring183from shortening.

Fourth Embodiment

A fourth embodiment is to be described below with reference to the drawings, focusing on the differences from the second embodiment. In this embodiment, the number of springs provided in the configuration on the second shear blade40side of the cutting apparatus is changed from two to one.

The configuration of the second shear blade40side of the cutting apparatus is to be described with reference toFIGS.19to21. Note that, inFIGS.19to21, some of the same configurations as, or the corresponding configurations to those described in the second and third embodiments are designated by the same reference numerals for convenience. In addition, some configurations are omitted to be shown in some drawings for convenience.

As shown inFIG.21, the cutting apparatus includes a contact portion190. The contact portion190is provided at the center of the lower surface of the extending portion65in the width direction of the second shear blade40. The contact portion190projects downward from the lower surface of the extending portion65. In this embodiment, the contact portion190is formed from a bolt. The tip part of the upper portion of the spring receiving portion175is in contact with the contact portion190. The head of the bolt, which is the contact portion190, may be have formed therein a concave portion with which the convex portion175bof the spring receiving portion175is in contact.

According to this embodiment described above, the same effect as that of the third embodiment can be obtained.

Other Embodiments

Each of the above embodiments may be modified for implementation as follows.

Any one of the first upper stopper portion80aand the first lower stopper portion80bmay be omitted from the cutting apparatus. In this case, the height dimension of any one of the first upper stopper portion80aand the first lower stopper portion80bonly needs to be adjusted so that the inclined portions of the first and second projecting portions32and42face each other in the horizontal direction when the first and second shear blades30and40are separated from each other.

In the first and second embodiments, any one of the second upper stopper portion81aand the second lower stopper portion81bmay be omitted from the cutting apparatus. In this case, the height dimension of any one of the second upper stopper portion81aand the second lower stopper portion81bonly needs to be adjusted so that the tip parts of the first and second shear blades30and40do not separate in the vertical direction when the tip parts of the first and second shear blades30and40overlap.

In the third embodiment, a concave portion with which the convex portion175bis in contact may be formed, on the lower surface of the extending portion65, instead of providing the contact portion74.

In the third embodiment, a convex portion may be formed on the contact portion74, and a concave portion with which the convex portion is in contact may be formed on the upper end part of the spring receiving portion175.

The configuration for applying the elastic force to the mounting portion60is not limited to the one illustrated in each of the above embodiments. For example, in a state in which the first upper stopper portion80ais in contact with the first lower stopper portion80b, a spring may be attached to an upper part of the extending portion65so that an elastic force for pulling the extending portion65upward is applied to the extending portion65.

In each of the above embodiments, when the tip parts of the first and second shear blades30and40overlap, the second shear blade40is arranged so as to be above the first shear blade30, but the present invention is not limited to this. The first shear blade30may be arranged so as to be above the second shear blade40. In this case, the first projecting portion32only needs to be inclined obliquely upward and the second projecting portion42only needs to be inclined obliquely downward. In addition, the molten glass cutting apparatus only needs to be configured such that an elastic force in a specific direction around the first axis for pressing the second shear blade40against the first shear blade30is applied to the mounting portion60.

In each of the above embodiments, the configuration for rotatably supporting the shear blade around the first and second axes is integrated on the second shear blade40side, but the present invention is not limited to this. For example, the first and second shear blades33and40may be configured such that: the base end part of the second shear blade40is provided with a configuration that rotatably supports the second shear blade43with respect to the second base portion70around the first axis; and the base end part of the first shear blade30may be provided with a configuration that rotatably supports the first shear blade30with respect to the first base portion50around the second axis. In this case, the first shear blade30side only needs to have a configuration such that an elastic force around the second axis is applied to the first shear blade30so that the respective cutting edge sides of the first and second shear blades30and40are placed along each other.