Patent Description:
Synthetic resin containers, typical examples of which include polypropylene (PP) bottles and polyethylene terephthalate (PET) bottles, are used to contain a variety of contents, such as beverages, cosmetics, pharmaceuticals, detergents, or toiletries like shampoo. Such a container is typically formed by biaxially stretch blow molding a synthetic resin preform into a predetermined shape using a blow molding apparatus, after the preform has been heated to a temperature at which a stretching effect may be achieved. The preform has been formed in a bottomed tubular shape by injection molding or the like.

Blow molding apparatuses that use incompressible fluids, such as pressurized liquids, instead of pressurized air, as pressurizing media to be supplied into preforms are known. In this case, contents which are to be ultimately filled into containers as products may be used as pressurizing incompressible fluids. By doing so, the step of filling contents into containers may be omitted, and the production process and the configurations of blow molding apparatuses may be simplified.

For example, Patent Literature (PTL) <NUM> describes a blow molding apparatus including a mold for blow molding, a blow nozzle placed above the mold, a pressurized fluid supply source that supplies a pressurized liquid to the blow nozzle, and a blow nozzle moving unit that causes the blow nozzle to move in a vertical direction relative to the mold. The blow molding apparatus is configured to mold a preform into a container having a shape corresponding to a cavity of the mold, by supplying a pressurized liquid into the preform through the blow nozzle in a state in which the blow nozzle is connected to a mouth of the preform. Further the disclosures of <CIT>, <CIT> and <CIT> may be helpful for understanding the present invention.

In a known blow molding apparatus as described in PTL <NUM>, after a preform has been blow molded into a container and when the blow nozzle is moved upward relative to the mold so as to be detached from a mouth of the container, an incompressible fluid can drip down from the surface of the blow nozzle to which it has adhered. In particular, in a case in which a relatively highly viscous liquid, such as shampoo or liquid detergent, is used as an incompressible fluid for blow molding, it takes long for the dripping down of the liquid to start from the blow nozzle or the like after blow molding. Moreover, the liquid continues to run in a thin stream for a while. Accordingly, the liquid is likely to drip down onto the molded container or the mold from which the container has been removed, possibly causing adhesion of the liquid thereto.

It would be helpful to provide a blow molding apparatus capable of preventing an incompressible fluid from dripping down from the blow nozzle and adhering to a molded container or the mold after blow molding.

The present invention refers to a blow molding apparatus according to claim <NUM>. Advantageous embodiments may include features of depending claims. Thus a blow molding apparatus according to the present disclosure includes:.

In a preferred embodiment of the present blow molding apparatus configured as above, the drawing orifice is open to the blow nozzle.

In another preferred embodiment of the present blow molding apparatus configured as above, the sealing body includes a tubular wall that is placed inside the blow nozzle when the sealing body is closed, and the tubular wall is provided, on an inner peripheral surface thereof, with a communication groove that extends upward from a lower end of the tubular wall and that communicates with the drawing orifice when the sealing body is closed.

In still another preferred embodiment of the present blow molding apparatus configured as above, the blow molding apparatus includes.

In still another preferred embodiment of the present blow molding apparatus configured as above, before the preform is blow molded, the blow molding apparatus is configured to perform an air discharge step of supplying the incompressible fluid into the preform to thereby discharge air inside the preform to the outside, and
in the air discharge step, the pressurized gas supply source is configured to operate so as to cause the incompressible fluid inside the drawing and discharging flow path to flow out through the drawing orifice toward the inside of the preform.

In still another preferred embodiment of the present blow molding apparatus configured as above, a piston member is provided on the drawing and discharging flow path, the piston member being configured to perform a pull operation when the fluid drawing source operates, so as to increase a storage space for storing the incompressible fluid inside the drawing and discharging flow path, and being configured to perform a push operation when the pressurized gas supply source operates, so as to reduce the storage space.

According to the present disclosure, a blow molding apparatus capable of preventing an incompressible fluid from dripping down from the blow nozzle and adhering to a molded container or the mold after blow molding can be provided.

Hereinafter, the present disclosure will be described in more details with reference to the drawings.

A blow molding apparatus <NUM> according to an embodiment of the present disclosure as illustrated <FIG> is configured to manufacture a container <NUM> (refer to <FIG>) having a predetermined shape (e.g., bottle shape), by blow molding a synthetic resin preform <NUM>.

In blow molding, incompressible fluids are used as pressurized media. As the incompressible fluids, for example, contents which are to be ultimately contained in the container <NUM>, such as beverages, cosmetics, pharmaceuticals, detergents, toiletries such as shampoo, or the like can be used. In the present embodiment, a liquid <NUM> is used as a pressurizing medium.

As the preform <NUM>, for example, a preform formed in a bottomed tubular shape including a cylindrical mouth 2a defining an open end, a cylindrical body 2b continuous with the mouth 2a, and a bottom 2c closing a lower end of the body 2b may be used. A thermoplastic resin material, such as polypropylene (PP) or polyethylene terephthalate (PET), may be used to form the preform <NUM>.

Although not illustrated in detail, the mouth 2a has an outer peripheral surface provided with an engagement projection, with which a closing cap can be fitted to the mouth of the molded container <NUM> by plugging (undercut engagement). Additionally, the outer peripheral surface of the mouth 2a may be configured to be provided with a male screw, instead of the engagement projection for plugging, and the closing cap may be fitted onto the mouth of the container <NUM> by screw connection.

The blow molding apparatus <NUM> includes a mold <NUM> for blow molding. The mold <NUM> has a cavity <NUM>, which has a shape corresponding to a final shape, such as a bottle shape, of the container <NUM>. The cavity <NUM> is open to an upper side at an upper surface of the mold <NUM>. The preform <NUM> is placed or fitted into the mold <NUM>, with the body 2b and the bottom 2c being arranged inside the cavity <NUM> of the mold <NUM> and with the mouth 2a protruding above the mold <NUM>.

The mold <NUM> is configured to be opened into left and right mold halves, for example. By opening the mold <NUM> into the left and right mold halves after molding the preform <NUM> into the container <NUM>, the container <NUM> can be removed from the mold <NUM>.

A nozzle unit <NUM> is provided above the mold <NUM>, so as to supply the pressurized liquid <NUM> into the preform <NUM>. The nozzle unit <NUM> includes a main body block <NUM>. The main body block <NUM> is provided, at a lower end thereof, with a support block <NUM>. The support block 22A supports a blow nozzle <NUM>, which is fitted to the lower end of the main body block <NUM>.

The blow nozzle <NUM>, which is made of a steel material, a resin material, or the like, includes a nozzle tip 23a. As illustrated in <FIG>, the nozzle tip 23a is formed in a cylindrical shape having an outer diameter smaller than an inner diameter of the mouth 2a of the preform <NUM>. The nozzle tip 23a has a lower end surface that abuts against a step portion formed on an inner surface of the mouth 2a of the preform <NUM>. Additionally, the outer diameter of the nozzle tip 23a may substantially be the same as the inner diameter of the mouth 2a of the preform <NUM>, and the outer peripheral surface of the nozzle tip 23a may abut against the inner peripheral surface of the mouth 2a. By inserting the nozzle tip 23a to the mouth 2a of the preform <NUM>, the blow nozzle <NUM> is connected to the mouth 2a. Further, an inverted cone shaped sealing surface 23b is provided on an upper surface of the blow nozzle <NUM>. The shape of the sealing surface 23b can be changed as appropriate. The sealing surface 23b may be configured by an inner peripheral surface of the blow nozzle <NUM> or by the upper surface and the inner peripheral surface of the blow nozzle <NUM>.

As illustrated in <FIG>, the blow molding apparatus <NUM> includes a blow nozzle moving unit <NUM>. The nozzle unit <NUM> (blow nozzle <NUM>) is driven by the blow nozzle moving unit <NUM>, so as to be movable between a connected position (the position illustrated in <FIG>) and a standby position (the position illustrated in <FIG>) in the vertical direction relative to the mold <NUM>. In the connected position, the blow nozzle <NUM> is connected in a sealed manner to the mouth 2a of the preform <NUM> from above that has been placed into the mold <NUM>. In the standby position, the blow nozzle <NUM> is above and away from the mouth 2a of the preform <NUM> that has been placed into the mold <NUM>.

Inside the nozzle unit <NUM> (more specifically, the main body block <NUM> and the blow nozzle <NUM>), a supply flow path <NUM> is provided so as to communicate with the blow nozzle <NUM>. The supply flow path <NUM> extends in the vertical direction inside the nozzle unit <NUM>. The nozzle unit <NUM> (more specifically, the main body block <NUM>) is provided with a liquid supply port <NUM>, which communicates with an upper end of the supply flow path <NUM>.

A sealing body <NUM> is placed inside the supply flow path <NUM>. The sealing body <NUM> can be seated on the sealing surface 23b of the blow nozzle <NUM>. As illustrated in <FIG>, the sealing body <NUM> is formed in a cylindrical shape, and it has an inverted cone shaped tapered surface 27a. The tapered surface 27a has a shape corresponding to the sealing surface 23b of the blow nozzle <NUM>. The sealing body <NUM> is fixed to a shaft body <NUM>, which is provided so as to be movable in the vertical direction relative to the nozzle unit <NUM>. The sealing body <NUM> is therefore movable in the vertical direction inside the supply flow path <NUM>. Additionally, the sealing body <NUM> may be formed integrally with the shaft body <NUM>.

When the sealing body <NUM> is driven by the shaft body <NUM> and moved to a closed position, that is, a lower stroke end position, its tapered surface 27a is seated on the sealing surface 23b, to thereby close the blow nozzle <NUM>. On the other hand, when the sealing body <NUM> is driven by the shaft body <NUM> and moved upward from the closed position, the tapered surface 27a of the sealing body <NUM> separates from the sealing surface 23b, to thereby open the blow nozzle <NUM>.

The nozzle unit <NUM> includes a discharge rod <NUM>. As illustrated in <FIG>, the discharge rod <NUM> is provided with a discharge orifice 29a for the liquid <NUM>. Further, an opening and closing body 29b for opening and closing the discharge orifice 29a is provided inside the discharge rod <NUM>. In the present embodiment, the discharge rod <NUM> is formed in a cylindrical shape with the discharge orifice 29a provided at a lower end thereof. The opening and closing body 29b is movable in the vertical direction relative to the discharge rod <NUM>. The opening and closing body 29b is fixed to a lower end of an opening and closing rod 29c, which extends along an axis of the discharge rod <NUM> on an inner side in a radial direction of the discharge rod <NUM>. The opening and closing body 29b is therefore configured to be driven by the opening and closing rod 29c in the vertical direction, so as to be able to open and close the discharge orifice 29a. An intratubular flow path 29d is defined between an inner peripheral surface of the discharge rod <NUM> and an outer peripheral surface of the opening and closing rod 29c. Additionally, the discharge rod <NUM> may have a tubular shape (such as an elliptical cylindrical or a polygonal cylindrical shape) other than a cylindrical shape. The opening and closing rod 29c may also have a columnar shape (such as an elliptical cylindrical or a polygonal cylindrical shape) other than a cylindrical shape.

In the present embodiment, the discharge orifice 29a is provided at the lower end of the discharge rod <NUM>. The discharge orifice 29a may, however, be provided on an outer peripheral surface of the discharge rod <NUM>, instead of or in addition to at the lower end. Further, the number and shape of discharge orifices 29a to be provided in the discharge rod <NUM> can be changed as appropriate.

The discharge rod <NUM> passes through the sealing body <NUM> and extends along the axis of the sealing body <NUM> and the shaft body <NUM>. The discharge rod <NUM> is movable in the vertical direction relative to the sealing body <NUM>. The discharge rod <NUM> and the opening and closing body 29b are driven individually or in cooperation with each other by a driving source that is not illustrated.

The discharge rod <NUM> may be used as a stretching rod that stretches the preform <NUM> in the axial direction by moving downward. The discharge rod <NUM> may, however, be configured not to be used as a stretching rod. It is also possible to use only the opening and closing body 29b and the opening and closing rod 29c as a stretching rod.

As illustrated in <FIG>, the discharge orifice 29a is connected to a first end of a first pipe P1 via the intratubular flow path 29d. A first opening and closing valve V1 is provided on the first pipe P1. The first opening and closing valve V1 can open and close the first pipe P1. The first opening and closing valve V1 is configured by, for example, a solenoid valve or an air valve, and it is controlled to open and close by a control means that is not illustrated.

A second end of the first pipe P1 is connected to a pressurized fluid supply unit <NUM> via a second pipe P2. Thus, the discharge orifice 29a is connected to the pressurized fluid supply unit <NUM> by a discharge path formed by the intratubular flow path 29d, the first pipe P1, and the second pipe P2.

In the present embodiment, the pressurized fluid supply unit <NUM> includes a cylinder 30a and a plunger 30b. The pressurized fluid supply unit <NUM> is configured by a plunger pump operable in both a pressurizing direction (positive direction) for pressurizing the liquid <NUM> and a drawing direction (opposite direction) for drawing the liquid <NUM>. Additionally, the pressurized fluid supply unit <NUM>, which can pressurize and draw the liquid <NUM>, may be another type of pump or the like.

The pressurized fluid supply unit <NUM> is connected to the liquid supply port <NUM> via the second pipe P2 and a third pipe P3. That is, the pressurized fluid supply unit <NUM> is connected to the blow nozzle <NUM> via the second pipe P2, the third pipe P3, the liquid supply port <NUM>, and the supply flow path <NUM>. The pressurized fluid supply unit <NUM> can supply the pressurized liquid <NUM> (incompressible fluid) to the blow nozzle <NUM>, by operating in the pressurizing direction. The liquid <NUM> is replenished to the pressurized fluid supply unit <NUM> from a tank that is not illustrated, as needed. A pressure gauge PG1 is provided on the third pipe P3, and measurement data of the pressure gauge PG1 is inputted to the aforementioned control means.

In the blow molding apparatus <NUM>, the blow nozzle <NUM> is connected to the mouth 2a of the preform <NUM> that has been placed into the mold <NUM>, with the nozzle unit <NUM> serving as a connected position. In this state, the sealing body <NUM> is opened, and the pressurized liquid <NUM> is supplied from the pressurized fluid supply unit <NUM> to the blow nozzle <NUM>, whereby the pressurized liquid <NUM> is supplied into the preform <NUM> through the blow nozzle <NUM>. The preform <NUM> can be thus blow molded into the container <NUM> having a shape corresponding to the cavity <NUM> of the mold <NUM>.

As illustrated in <FIG>, the blow molding apparatus <NUM> includes a fluid drawing and flowing out mechanism <NUM>. The fluid drawing and flowing out mechanism <NUM> includes a drawing and discharging flow path <NUM> communicating with a drawing orifice <NUM>, a fluid drawing source <NUM> connected to the drawing and discharging flow path <NUM> via a fourth pipe P4, and a pressurized gas supply source <NUM> connected to the drawing and discharging flow path <NUM> via a fifth pipe P5.

As illustrated in <FIG>, for example, the drawing orifice <NUM> may be configured to open to the inner peripheral surface of the nozzle tip 23a in part of the blow nozzle <NUM> that is located downstream of the sealing surface 23b. Although in the present embodiment the drawing orifice <NUM> is open to the inner peripheral surface of the nozzle tip 23a of the blow nozzle <NUM>, the drawing orifice <NUM> may be provided so as to open at another part of the nozzle tip 23a of the blow nozzle <NUM> other than the inner peripheral surface (e.g., the lower end surface of the nozzle tip 23a). Further, the drawing orifice <NUM> may be provided on a member, such as a pipe material, different from the blow nozzle <NUM>, and it may be configured to be placed below the blow nozzle <NUM> when the blow nozzle <NUM> is set to the standby position.

The drawing and discharging flow path <NUM> communicates with the drawing orifice <NUM>. The drawing and discharging flow path <NUM> also extends from the inside of the blow nozzle <NUM> and the support block <NUM> to the outside, so as to be connected to the fourth pipe P4 and the fifth pipe P5.

Additionally, the number of drawing orifices <NUM> and the number of drawing and discharging flow paths <NUM> are not limited to one. An annular continuous groove may be provided on an outer peripheral surface of the blow nozzle <NUM> that faces an inner peripheral surface of the support block <NUM>. A plurality of drawing and discharging flow paths <NUM>, each communicating with the continuous groove, may be provided on the blow nozzle <NUM> so as to be arranged radially and at intervals in the circumferential direction. A plurality of drawing orifices <NUM> may be configured to be open to the inner peripheral surface of the nozzle tip 23a.

A second opening and closing valve V2 is provided on the fourth pipe P4. The second opening and closing valve V2 can open and close the fourth pipe P4. A third opening and closing valve V3 is provided on the fifth pipe P5. The third opening and closing valve V3 can open and close the fifth pipe P5. The second opening and closing valve V2 and the third opening and closing valve V3 are configured by, for example, a solenoid valve or an air valve, and they are controlled to open and close by a control means that is not illustrated.

Further, a pressure gauge PG2 and a check valve <NUM> are provided on the fifth pipe P5. Measurement data of the pressure gauge PG2 is inputted to the aforementioned control means.

The fluid drawing source <NUM> may be configured by, for example, a drawing pump or the like. After blow molding is completed, and after the blow nozzle <NUM> is moved from the connected position to the standby position while the sealing body <NUM> is closed, the fluid drawing source <NUM> applies drawing force to the drawing and discharging flow path <NUM>. The fluid drawing source <NUM> thus operates so as to draw the liquid <NUM> adhering to the blow nozzle <NUM> into the drawing and discharging flow path <NUM>. It is to be noted that drawing force may be applied to the drawing and discharging flow path <NUM> during movement from the connected position to the standby position, without being limited to after completion of movement to the standby position. The operation of the fluid drawing source <NUM> is controlled by the aforementioned control means.

The pressurized gas supply source <NUM> may be configured, for example, by a pressurizing pump or the like. After blow molding is completed and after the next preform <NUM> is placed into the mold <NUM>, the pressurized gas supply source <NUM> supplies a pressurized gas to the drawing and discharging flow path <NUM>. The pressurized gas supply source <NUM> thus operates so as to cause the liquid <NUM> that has been drawn into the drawing and discharging flow path <NUM> by the fluid drawing source <NUM> to flow out though the drawing orifice <NUM> toward the inside of the preform <NUM> or toward the inside of a container <NUM> into which the preform <NUM> is to be blow molded. The operation of the pressurized gas supply source <NUM> is controlled by the aforementioned control means.

Additionally, a drawing and pressurizing pump (e.g., a plunger pump) in which a drawing pump and a pressurizing pump are integrated may be connected to the drawing and discharging flow path <NUM>. The drawing and pressurizing pump may be configured to function as the fluid drawing source <NUM> and the pressurized gas supply source <NUM>.

A fourth opening and closing valve V4 is provided on the drawing and discharging flow path <NUM>. The fourth opening and closing valve V4 can open and close the drawing and discharging flow path <NUM>. The fourth opening and closing valve V4 is configured by, for example, a solenoid valve or an air valve, and it is controlled to open and close by a control means that is not illustrated.

The fluid drawing and flowing out mechanism <NUM> may be configured with a piston member <NUM> that is located closer to the fluid drawing source <NUM> or the pressurized gas supply source <NUM> than to the fourth opening and closing valve V4 on the drawing and discharging flow path <NUM>. As illustrated in <FIG>, the piston member <NUM> is provided integrally with a shaft body <NUM>, which is provided on an axis thereof with a through hole that communicates with the drawing and discharging flow path <NUM>. The piston member <NUM> can make advancing and retracting movements in a cylinder <NUM> along the drawing and discharging flow path <NUM>. The advancing and retracting movements of the piston member <NUM> are driven by a working fluid supplied to the cylinder <NUM>.

When the fluid drawing source <NUM> is operated, the piston member <NUM> performs a pull operation in a direction from the fourth opening and closing valve V4 toward the fluid drawing source <NUM> or the pressurized gas supply source <NUM>. Consequently, a majority of the shaft body <NUM> is moved out of the drawing and discharging flow path <NUM> into the cylinder <NUM>, so as to increase a storage space <NUM> formed inside the drawing and discharging flow path <NUM> for storing the liquid <NUM> (as in the state illustrated in <FIG>). Further, when the pressurized gas supply source <NUM> is operated, the piston member <NUM> performs a push operation in a direction from the fluid drawing source <NUM> or the pressurized gas supply source <NUM> toward the fourth opening and closing valve V4. Consequently, the shaft body <NUM> is moved to protrude out of the cylinder <NUM> along an inner peripheral surface of the drawing and discharging flow path <NUM>, so as to reduce the storage space <NUM> (as in the state illustrated in <FIG>). By moving the shaft body <NUM> to protrude out of the cylinder <NUM> along the inner peripheral surface of the drawing and discharging flow path <NUM>, the liquid <NUM> adhering to the inner peripheral surface of the storage space <NUM> can be pushed toward the drawing orifice <NUM> by the shaft body <NUM>.

As illustrated in <FIG>, an open flow path <NUM> that is open to the atmosphere is provided inside the blow nozzle <NUM> and the support block <NUM>. A fifth opening and closing valve V5 is provided on the open flow path <NUM>. The fifth opening and closing valve V5 can open and close the open flow path <NUM>. The fifth opening and closing valve V5 is configured by, for example, a solenoid valve or an air valve, and it is controlled to open and close by a control means that is not illustrated.

After blow molding is completed, the blow nozzle <NUM> is moved from the connected position to the standby position by the blow nozzle moving unit <NUM>, while the sealing body <NUM> is closed. After and/or during the movement, as illustrated in <FIG>, the fluid drawing and flowing out mechanism <NUM> operates the fluid drawing source <NUM> and also causes the piston member <NUM> to perform a pull operation, in a state in which the first opening and closing valve V1 and the third opening and closing valve V3 are closed, the second opening and closing valve V2 and the fourth opening and closing valve V4 are opened, and the fifth opening and closing valve V5 is opened or closed. Consequently, the liquid <NUM> adhering to the blow nozzle <NUM> can be drawn into the drawing and discharging flow path <NUM> through the drawing orifice <NUM> and stored in the storage space <NUM>.

Further, after blow molding is completed, and after the blow molded container <NUM> is removed from the mold <NUM> and the next preform <NUM> is placed into the mold <NUM> (specifically, after the next preform <NUM> is placed into the mold <NUM> and before a container <NUM> into which the preform <NUM> is to be blow molded is removed from the mold <NUM>), as illustrated in <FIG>, the fluid drawing and flowing out mechanism <NUM> operates the pressurized gas supply source <NUM> in a state in which the first opening and closing valve V1, the third opening and closing valve V3, and the fourth opening and closing valve V4 are opened, and the second opening and closing valve V2 and the fifth opening and closing valve V5 are closed. Consequently, the liquid <NUM> stored in the storage space <NUM> can be pushed out by a pressurized gas, so as to flow out through the drawing orifice <NUM> toward the inside of the preform <NUM> or toward the inside of the container <NUM> into which this preform <NUM> is to be blow molded. At this time, the piston member <NUM> is caused to perform a pull operation, so that the liquid <NUM> adhering to the inner peripheral surface of the storage space <NUM> can be pushed out toward the drawing orifice <NUM> by the shaft body <NUM>. Thus, it is ensured that the liquid <NUM> can flow out through the drawing orifice <NUM> without remaining in the storage space <NUM>.

As illustrated in <FIG>, the sealing body <NUM> includes a tubular wall <NUM> that is placed inside the blow nozzle <NUM> when the sealing body <NUM> is closed. The tubular wall <NUM> may be configured to be provided, on an inner peripheral surface thereof, with a communication groove <NUM> that extends upward from a lower end of the tubular wall <NUM> and that communicates with the drawing orifice <NUM> when the sealing body <NUM> is closed. In this case, the tubular wall <NUM> may also be configured to be provided, on the inner peripheral surface, with a plurality of communication grooves <NUM> arranged at intervals in the circumferential direction.

The tubular wall <NUM> may be configured to include an outer peripheral surface that faces the inner peripheral surface of the nozzle tip 23a of the blow nozzle <NUM> with a slight gap therebetween. The outer peripheral surface of the tubular wall <NUM> may also be configured to be in sliding contact with the inner peripheral surface of the nozzle tip 23a of the blow nozzle <NUM>. Additionally, the outer peripheral surface of the discharge rod <NUM> is in sliding contact with the inner peripheral surface of the tubular wall <NUM>.

The blow molding apparatus <NUM> is configured to blow mold a synthetic resin preform <NUM> into a container <NUM> having a predetermined shape (liquidcontaining container <NUM> in which a liquid <NUM> is contained), by performing the following operations.

First, the blow molding apparatus <NUM> performs a standby step. In the standby step, as illustrated in <FIG>, the blow nozzle <NUM> is in a standby position in which it is located above and away from the mouth 2a of the preform <NUM> which has been placed into the mold <NUM>, the sealing body <NUM> closes the blow nozzle <NUM>, and the discharge orifice 29a of the discharge rod <NUM> is in a state of being closed by the opening and closing body 29b.

In the standby step, the preform <NUM> has been heated to a predetermined temperature around which stretchability can be achieved using a heating means (not illustrated), such as a heater, in advance. The preform <NUM> is placed into the mold <NUM>, and the mold <NUM> is closed. At this time, because the mouth 2a of the preform <NUM> is open, the preform <NUM> is in a state of being filled with air.

Secondly, an air discharge step is performed in the present embodiment. In the air discharging step, as illustrated in <FIG>, the nozzle unit <NUM> is lowered, the blow nozzle <NUM> is set to the connected position in which it is connected to the mouth 2a of the preform <NUM>, and the fifth opening and closing valve V5 is opened to thereby set the open flow path <NUM> to an exposed-to-atmosphere state. Then, the discharge rod <NUM> is lowered so that the discharge orifice 29a is open at the bottom 2c of the preform <NUM>, while the blow nozzle <NUM> remains closed by the sealing body <NUM>. Further, the first opening and closing valve V1 is set to the open state. In this state, the pressurized fluid supply unit <NUM> is operated in the pressurizing direction, so as to supply the liquid <NUM> into the preform <NUM> through the discharge orifice 29a. The pressure of the liquid <NUM> that is supplied into the preform <NUM> by the pressurized fluid supply unit <NUM> in the air discharge step is preferably set to a level that does not substantially stretch (expand) the preform <NUM>. Additionally, a discharge path for air can also be achieved by not engaging the blow nozzle <NUM> with the mouth 2a of the preform <NUM>, instead of discharging air inside the preform <NUM> through the open flow path <NUM>.

When the air discharge step is completed, as illustrated in <FIG>, air inside the preform <NUM> has been discharged to the atmosphere (outside) through the open flow path <NUM>, so that the air inside the preform <NUM> is replaced by the liquid <NUM>. When the air discharge step is completed, the discharge orifice 29a, the first opening and closing valve V1, and the fifth opening and closing valve V5 are closed.

Thus, in the air discharging step, the liquid <NUM> is supplied through the discharge orifice 29a of the discharge rod <NUM>, rather than being supplied into the preform <NUM> by opening the blow nozzle <NUM> by the sealing body <NUM>. Consequently, the liquid <NUM> is prevented from entering the inner peripheral surface of the blow nozzle <NUM>, and air can be smoothly discharged out of the preform <NUM> through the open flow path <NUM>. Further, in the air discharge step, the liquid <NUM> is supplied in a state in which the discharge orifice 29a is positioned at the bottom 2c of the preform <NUM>. This allows the discharge orifice 29a to be immersed in the liquid <NUM> immediately after it is supplied, and further liquid <NUM> can be supplied inside the liquid <NUM>. This can effectively prevent entrainment of air that causes bubbles or the like to be formed in the liquid <NUM> filled into the preform <NUM>. The prevention of entrainment can in turn prevent air entrainment into the liquid <NUM> inside a container <NUM> that is to be formed by a later-described blow molding step. Accordingly, a headspace having a desired size can be reliably formed in a later-described suck-back step. Further, the prevention of entrainment can also reduce the number of bubbles contained in the liquid <NUM> that will be returned into the nozzle unit <NUM> in the suck-back step. Accordingly, air entrainment into the supply flow path <NUM> can also be prevented, and stability of molding conditions, moldability of the container <NUM>, or the like can be improved.

Additionally, the air discharging step can be performed by supplying the liquid <NUM> by opening the blow nozzle <NUM> by the sealing body <NUM>, instead of thus supplying the liquid <NUM> through the discharge orifice 29a of the discharge rod <NUM>. Further, the air discharge step may also be omitted.

Upon completion of the air discharge step, the blow molding step is subsequently performed. In the blow molding step, as illustrated in <FIG>, the blow nozzle <NUM> is in a state of engaging with the mouth 2a of the preform <NUM>. In this state, the pressurized fluid supply unit <NUM> is operated, and the sealing body <NUM> is opened so as to release the blow nozzle <NUM>, so that the pressurized liquid <NUM> is supplied into the preform <NUM> through the blow nozzle <NUM>. Thus, the preform <NUM> is stretched by the pressure of the liquid <NUM>, and as illustrated in <FIG>, it is blow molded into a container <NUM> containing the liquid <NUM> and having a shape corresponding to the cavity <NUM> of the mold <NUM>.

Additionally, in the present embodiment, the discharge orifice 29a is in a state of being closed in the blow molding step. The discharge orifice 29a may, however, be configured to be in an open state, so as to supply the liquid <NUM> into the preform <NUM> further through it.

Further, in the blow molding step, the body 2b of the preform <NUM> may be stretched in the axial direction (longitudinal direction) by the discharge rod <NUM>, by moving the discharge rod <NUM> downward. In this case, biaxially stretch blow molding can be performed in which the preform <NUM> is blow molded while being stretched in the axial direction by the discharge rod <NUM>. Consequently, the preform <NUM> can be molded into a container <NUM> having a predetermined shape with even higher accuracy.

The blow molding step is performed in a state in which a majority of air in the preform <NUM> has been discharged to the outside by the air discharge step. Accordingly, when the pressurized liquid <NUM> is supplied into the preform <NUM>, the liquid <NUM> does not entrain air, and therefore, entrainment of air into the liquid <NUM> inside the container <NUM> is prevented.

Upon completion of the blow molding step, the suck-back step is subsequently performed. In the present embodiment, the suck-back step is configured to include a first suck-back step and a second suck-back step performed after the first suck-back step. In the first suck-back step, as illustrated in <FIG>, in a state in which the discharge rod <NUM> extends to the bottom of the container <NUM>, the sealing body <NUM>, the discharge orifice 29a, and the first opening and closing valve V1 are set to open states. In this state, the pressurized fluid supply unit <NUM> is caused to perform a drawing operation, so that a predetermined amount of the liquid <NUM> is sucked back from the inside of the container <NUM> toward the supply flow path <NUM> and the intratubular flow path 29d (discharge path). In the second suck-back step, as illustrated in <FIG>, the sealing body <NUM> is closed, while the discharge orifice 29a and the first opening and closing valve V1 remain in the open states, and the pressurized fluid supply unit <NUM> is caused to perform a drawing operation, so that a predetermined amount of the liquid <NUM> is sucked back from the inside of the container <NUM> toward the intratubular flow path 29d (discharge path). Due to the sack-back step, a predetermined amount of the liquid <NUM> is discharged out of the container <NUM>, whereby a headspace H having a desired size is formed in the container <NUM>. For example, the first suck-back step may be performed to the extent where the pressurized state in the container <NUM> is released, and the second suck-back step may be set so as to substantially form the headspace H.

Further, in the present embodiment, in the second suck-back step, the pressurized gas supply source <NUM> is operated in a state in which the third opening and closing valve V3 and the fourth opening and closing valve V4 are opened. Accordingly, when the pressurized gas supply source <NUM> is operated, a pressurized gas is supplied into the container <NUM> via the drawing orifice <NUM> and the communication grooves <NUM> through the drawing and discharging flow path <NUM>. The pressure of the gas pushes the liquid <NUM> to be effectively discharged out of the container <NUM> through the intratubular flow path 29d (discharge path). In this way, in the second suck-back step, the pressurized gas supply source <NUM> is configured to supply a pressurized gas into the container <NUM>. Consequently, suck-back is assisted, and the time required for the second suck-back step can be reduced.

Further, in the second suck-back step, when the pressurized gas supply source <NUM> is operated, the piston member <NUM> performs a push operation in a direction from the fluid drawing source <NUM> or the pressurized gas supply source <NUM> toward the fourth opening and closing valve V4. When the piston member <NUM> performs the push operation, the shaft body <NUM> moves and protrudes out of the cylinder <NUM> along the inner peripheral surface of the drawing and discharging flow path <NUM>, so as to reduce the storage space <NUM> (as in the state illustrated in <FIG>). By thus causing the shaft body <NUM> to move and protrude out of the cylinder <NUM> along the inner peripheral surface of the drawing and discharging flow path <NUM>, the liquid <NUM> adhering to the inner peripheral surface of the storage space <NUM> can be pushed toward the drawing orifice <NUM> by the shaft body <NUM>.

Additionally, the blow molding apparatus <NUM> may be configured to perform only one of the first suck-back step and the second suck-back step as the suck-back step, or it may be configured not to perform the suck-back step.

Upon completion of the second suck-back step, as illustrated in <FIG>, the discharge orifice 29a and the first opening and closing valve V1 are closed, the discharge rod <NUM> is raised and returned to the original position, and the nozzle unit <NUM> is raised to the standby position.

When the nozzle unit <NUM> has moved to the standby position, the liquid <NUM> adhering to the surface of the blow nozzle <NUM> can drip down. In the blow molding apparatus <NUM> according to the present embodiment, however, when the nozzle unit <NUM> has moved to the standby position, the fluid drawing source <NUM> is operated in a state as illustrated in <FIG> in which the first opening and closing valve V1 and the third opening and closing valve V3 are closed, the second opening and closing valve V2 and the fourth opening and closing valve V4 are opened, and the fifth opening and closing valve V5 is opened or closed. Accordingly, the liquid <NUM> adhering to the blow nozzle <NUM> can be drawn into the drawing and discharging flow path <NUM> through the drawing orifice <NUM>, thus being prevented from dripping down. After blow molding, the liquid <NUM> is therefore prevented from dripping from the blow nozzle <NUM> and adhering to the molded container <NUM> or the mold <NUM>.

Further, in the present embodiment, after the liquid <NUM> adhering to the blow nozzle <NUM> has been drawn into the drawing and discharging flow path <NUM> through the drawing orifice <NUM> by operating the fluid drawing source <NUM>, another second suck-back step is performed in a process in which the next preform <NUM> placed into the mold <NUM> is molded into a container <NUM>. During this time, the pressurized gas supply source <NUM> is operated in a state in which the first opening and closing valve V1, the third opening and closing valve V3, and the fourth opening and closing valve V4 are open, and the second opening and closing valve V2 and the fifth opening and closing valve V5 are closed. By doing so, the liquid <NUM> which has been drawn into the drawing and discharging flow path <NUM> is pushed out by a pressurized gas and flows out toward the inside of the container <NUM> through the drawing orifice <NUM>, so as to return into the container <NUM>. Loss of the liquid <NUM> can therefore be prevented, by not discharging the liquid <NUM> to the outside after it has been drawn into the drawing and discharging flow path <NUM>.

Thus, in the blow molding apparatus <NUM> according to the present embodiment, after blow molding is completed and when the blow nozzle <NUM> is moved from the connected position to the standby position, the fluid drawing source <NUM> is operated so as to apply drawing force to the drawing and discharging flow path <NUM>. By doing so, the liquid (incompressibility fluid) <NUM> that adheres to the blow nozzle <NUM> during blow molding can be drawn into the drawing and discharging flow path <NUM>. Consequently, the liquid (incompressible fluid) <NUM> adhering to the blow nozzle <NUM> is prevented from dripping down and adhering to the molded container <NUM> or the mold <NUM>.

Further, in the blow molding apparatus <NUM> according to the present embodiment, after blow molding is completed and the next preform <NUM> is placed into the mold <NUM>, the pressurized gas supply source <NUM> is operated. By doing so, the liquid (incompressible fluid) <NUM> that has been drawn into the drawing and discharging flow path <NUM> by the fluid drawing source <NUM> is pushed out by a pressurized gas, so as to be returned through the drawing orifice <NUM> into the preform <NUM> or a container <NUM> that is to be formed by blow molding the preform <NUM>. Thus, even with a configuration in which the liquid adhering to the blow nozzle <NUM> is drawn into the drawing and discharging flow path <NUM> and therefore prevented from dripping down, loss of the liquid <NUM> can be prevented by not discharging the liquid <NUM> to the outside after it has been drawn into the drawing and discharging flow path <NUM>.

In the blow molding apparatus <NUM> according to the present embodiment, the drawing orifice <NUM> is configured to open to the blow nozzle <NUM>. For this reason, when the fluid drawing source <NUM> is operated, the liquid (incompressible fluid) <NUM> adhering to the blow nozzle <NUM> can be more efficiently drawn into the drawing and discharging flow path <NUM>.

Further, in the blow molding apparatus <NUM> according to the present embodiment, the sealing body <NUM> includes the tubular wall <NUM> that is placed inside the blow nozzle <NUM> when the sealing body <NUM> is closed. Further, the tubular wall <NUM> is provided, on the inner peripheral surface thereof, with the communication grooves <NUM> that extend upward from the lower end of the tubular wall <NUM> and that communicate with the drawing orifice <NUM> when the sealing body <NUM> is closed. For this reason, in addition to the liquid (incompressibility fluid) <NUM> that adheres to the blow nozzle <NUM>, the liquid (incompressible fluid) <NUM> that adheres to the outer peripheral surface of the discharge rod <NUM> during blow molding and then adheres to the lower end of the sealing body <NUM> by being drawn through the inner peripheral surface of the sealing body <NUM> when the discharge rod <NUM> is raised can be effectively drawn into the drawing and discharging flow path <NUM>. Thus, the liquid (incompressible fluid) <NUM> can be more reliably prevented from dripping down and adhering to the molded container <NUM> and the mold <NUM> after blow molding.

Moreover, in the blow molding apparatus <NUM> according to the present embodiment, the piston member <NUM> is configured to perform a push operation when the liquid <NUM> that has been drawn into the drawing and discharging flow path <NUM> is pushed out by a pressurized gas. For this reason, by pushing the liquid <NUM> adhering to the inner peripheral surface of the storage space <NUM> toward the drawing orifice <NUM> by the shaft body <NUM>, it is further ensured that the liquid <NUM> is returned into the container <NUM> without remaining in the storage space <NUM>.

Needless to say, the present disclosure is not limited to the above embodiment, and various changes may be made without departing from the gist of the present disclosure.

For example, although in the above embodiment the liquid <NUM> that has been drawn into the drawing and discharging flow path <NUM> by operating the fluid drawing source <NUM> is returned into the container <NUM> in the second suck-back step, the present disclosure is not limited to this example. For example, the pressurized gas supply source <NUM> may be configured to operate during the air discharge step illustrated in <FIG>, in a state in which the second opening and closing valve V2 is closed and the third opening and closing valve V3 and the fourth opening and closing valve V4 are opened, so that the liquid <NUM> that has been drawn into the drawing and discharging flow path <NUM> (storage space <NUM>) is pushed out by a pressurized gas and/or the shaft body <NUM> and flow out toward the inside of the preform <NUM> through the drawing orifice <NUM>, so as to return into the preform <NUM>. The timing of returning the liquid <NUM> that has been drawn into the drawing and discharging flow path <NUM> into the preform <NUM> or the container <NUM> may be changed in various ways.

Claim 1:
A blow molding apparatus (<NUM>) that includes:
a mold (<NUM>) for blow molding;
a blow nozzle (<NUM>) placed above the mold (<NUM>);
a sealing body (<NUM>) configured to open and close the blow nozzle (<NUM>); and
a pressurized fluid supply unit (<NUM>) configured to supply a pressurized incompressible fluid (<NUM>) to the blow nozzle (<NUM>); and
a blow nozzle moving unit (<NUM>) configured to move the blow nozzle (<NUM>) relative to the mold (<NUM>) between a connected position, in which the blow nozzle (<NUM>) is connected to a mouth (2a) of a preform (<NUM>) placed into the mold (<NUM>), and a standby position, in which the blow nozzle (<NUM>) is above and away from the mouth (2a), wherein
the pressurized incompressible fluid (<NUM>) is supplied into the preform (<NUM>) from the pressurized fluid supply unit (<NUM>) through the blow nozzle (<NUM>) that is in the connected position, so as to blow mold the preform (<NUM>) into a container (<NUM>) having a shape corresponding to a cavity (<NUM>) of the mold (<NUM>),
the blow molding apparatus (<NUM>) comprising:
a drawing and discharging flow path (<NUM>) connected to a drawing orifice (<NUM>); and
a fluid drawing source (<NUM>) connected to the drawing and discharging flow path (<NUM>), the fluid drawing source (<NUM>) being configured to apply drawing force to the drawing and discharging flow path (<NUM>), after blow molding is completed and after and/or while the blow nozzle (<NUM>) is moved from the connected position to the standby position while the sealing body (<NUM>) is closed, so as to draw the incompressible fluid (<NUM>) adhering to the blow nozzle (<NUM>) into the drawing and discharging flow path (<NUM>);
characterized by the blow molding apparatus (<NUM>) further comprising
a pressurized gas supply source (<NUM>) connected to the drawing and discharging flow path (<NUM>), the pressurized gas supply source (<NUM>) being configured to supply a pressurized gas to the drawing and discharging flow path (<NUM>), after blow molding is completed and after a next preform (<NUM>) is placed into the mold (<NUM>), so as to cause the incompressible fluid (<NUM>) that has been drawn into the drawing and discharging flow path (<NUM>) by the fluid drawing source (<NUM>) to flow out through the drawing orifice (<NUM>) toward the inside of the preform (<NUM>) or toward the inside of a container (<NUM>) into which the preform (<NUM>) is to be blow molded.