JP6547437B2 - Blow molding apparatus and blow molding method - Google Patents

Description

  The present invention relates to a blow molding apparatus and a blow molding method for obtaining a molded article by blow molding from a hollow parison.

  In blow molding, a hollow parison continuously discharged from an extrusion die is held between a pair of molds and divided, and then a blow pin (or blow nozzle) is inserted into the parison in the mold to produce a parison. Blow air is blown into the inside to form a hollow molded article corresponding to the cavity in the mold (see Patent Document 1 below).

  Also, conventionally, a parison holding plate which protrudes in the mold clamping direction from the divided surface of the mold (split mold) at a position below the pinch-off of the bottom cavity in the mold and holds the parison earlier than the split surface of the split mold when clamping. There is known a blow molding mold in which the parison holding plate is provided slidably in the opening and closing direction of the split mold (see Patent Document 2 below).

Unexamined-Japanese-Patent No. 10-323887 JP 2001-150526 A

  In the prior art in which a blow pin or a blow nozzle is inserted into a parison in a mold after holding a hollow parison with a mold, the parison is blow molded after mold clamping, so a bottle or flat bottle with a large blow ratio is molded In this case, the expansion of the parison by blow molding is limited, and there is a problem that high molding quality can not be obtained. On the other hand, when the blow pressure is increased to improve the molding quality, blow molding or blowout occurs when blow molding a bottle or flat bottle having a large blow ratio, and molding defects may occur. is there.

  On the other hand, as in the prior art described above, when using a mold provided with a parison holding plate, the parison can be held in the pinch-off lower position before the mold is clamped, and the support sent from the extrusion die With air, the parison can be pre-blow molded before the mold is clamped.

  According to such a conventional technique, since the parison can be clamped in a slightly expanded state by preliminary blow molding using support air sent from the extrusion die, the blow ratio after clamping can be suppressed to a certain degree. However, since preliminary blow molding can not be performed unless the mold (split mold) is in the close state, there is also a problem that the expansion of the parison by the preliminary blow molding is limited, and the blow ratio after mold clamping is effective. There was a problem that could not be made smaller.

  Also, in this prior art, since the preliminary blow molding is performed with the support air sent from the extrusion die and the mold clamping blow molding performed after mold clamping is performed by the insertion of the blow pin, the preliminary blow molding and mold clamping blow molding are continuously performed. It can not be done, and the pressure in the parison will temporarily decrease after parison cutting, which has the problem of adversely affecting the molding quality.

  Furthermore, since this prior art basically has a structure in which the continuously discharged parison is directly gripped by the mold, it is difficult to grip the parison at the center of the mold with high accuracy. In addition, there is a problem that the handling of the molded product after molding and mold opening can not be freely controlled.

  The present invention takes an example of the problem to address such a problem. That is, by enhancing the molding quality of a bottle or flat bottle having a large blow ratio, expanding the parison without restriction by preliminary blow molding, effectively reducing the blow ratio after clamping, preliminary blow molding and mold The object of the present invention is to improve molding quality by continuously performing blow molding and to be able to freely control the supply of parison to a mold and the handling of a molded article after mold opening. It is.

In order to achieve such an object, the blow molding apparatus according to the present invention has the following configuration.
A pair of holding chucks provided with a parison cutter for holding the discharged parison, a pair of parison chucks for holding the parison at upper and lower two places inside the pair of holding chucks, and the parison cut by the parison cutter A mold for holding the pair of parison chucks; and a blow device for inserting a blow nozzle into the parison through one of the pair of parison chucks, the pair of parison chucks comprising It is disposed outside, one grips the parison in the open state, the other closes and grips the parison, and the blow device performs preliminary blow molding of the parison before the mold clamps the parison, A blow molding apparatus characterized by performing mold clamping blow molding of a parison after a mold clamps a parison.

Moreover, the blow molding method according to the present invention has the following configuration.
The discharged parison, and the parison holding step of holding a pair of holding chuck having a parison cutter and the parison gripping step of gripping at two vertical positions of the parison by a pair of parison chuck between said pair of holding chuck, said The parison is cut by a parison cutter, and then a blow nozzle is inserted into the parison through one of the pair of parison chucks, and the parison gripped by the pair of parison chucks is blow molded by the blow nozzle. a step, by arranging the pair of parison chuck on the outside of the mold, the parison said gripped by a pair of parison chuck sandwiched in the mold, the parison is sandwiched by the mold, by the blow nozzle And a blow-molding mold clamping blow molding process. Molding method.

  The present invention having such characteristics can improve the forming quality of bottles having a large blow ratio, such as flat bottles, etc., and prior to blow by a mold, preliminary blow of parison held by a pair of parison chucks is performed. Since the molding is performed, the parison can be expanded without limitation when performing the preliminary blow molding, and the blow ratio by the clamp blow molding can be effectively reduced.

  In addition, since mold-clamping blow molding can be performed by a blow nozzle inserted into the parison at the time of performing preliminary blow-molding, it is possible to continuously perform the preliminary blow-molding and the mold-clamping blow molding to improve the molding quality. Can.

  In addition, since the parison discharged from the extrusion die can be held by the pair of parison chucks and supplied to the mold, and the molded product after mold opening can be held by the pair of parison chucks and taken out, the parison mold It is possible to freely control the feeding of the mold and the handling of the molded article after mold opening.

The parison chuck of the blow molding apparatus which concerns on embodiment of this invention, and explanatory drawing which shows the parison holding process of the blow molding method which concerns on embodiment of this invention, (a) is the state which held the parison with a pair of parison chuck Sectional drawing shown, (b) is a top view which shows one parison chuck (1st chuck), (c) is a top view which shows the other parison chuck (2nd chuck). It is explanatory drawing which shows the pre-blow molding process of the parison chuck | zipper of the blow molding apparatus which concerns on embodiment of this invention, a metal mold | die, and a blow device (blow nozzle), and the blow molding method which concerns on embodiment of this invention. It is an explanatory view showing a parison chuck, a die and a blow device (blow nozzle) of a blow molding device according to an embodiment of the present invention and a mold clamping blow molding step of a blow molding method according to an embodiment of the present invention. It is an explanatory view showing a series of operations of a blow molding device and a blow molding method concerning an embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, the blow molding apparatus according to the embodiment of the present invention includes a pair of parison chucks 10, a mold 20, and a blow apparatus 30. In the figure, the discharge direction (vertical direction) of the parison is the Z direction, the open / close direction of the parison chuck 10 is the X direction, and the direction orthogonal to them is the Y direction.

  As shown in FIG. 1A, the pair of parison chucks 10 is provided with a first chuck 11 and a second chuck 12 that hold a hollow parison P discharged from an extrusion die (not shown) at two upper and lower positions. ing. The first chuck 11 holds the upper side (one side) of the parison P, whereby the parison P is held in the open state. On the other hand, the second chuck 12 grips the lower side (the other side) of the parison P, whereby the parison P is gripped in the closed state.

  The second chuck 12 holds the vicinity of the lower end of the parison P discharged from the extrusion die, and an interval H equal to or more than the height of the mold 20 described later from the holding position of the second chuck 12 The grip position of is set. The pair of parison chucks 10 is provided with drive means (not shown). The driving means performs an opening / closing operation mechanism for opening and closing the parison P, and before or after gripping the parison P, the pair of parison chucks 10 in the discharge direction (vertical direction) of the parison P or a direction crossing it The movement movement mechanism which moves to

  FIG. 1B shows an example of the configuration of the first chuck 11. As illustrated, the first chuck 11 includes a pair of left and right chuck pieces 11A and 11B. Recesses 11t1 and 11t2 for gripping the parison P in an open state respectively face the chuck pieces 11A and 11B. The opening 11s is formed by combining the concave portions 11t1 and 11t2. The opening 11s is an insertion port of a blow nozzle described later.

  FIG. 1C shows a configuration example of the second chuck 12. As illustrated, the second chuck 12 includes a pair of left and right chuck pieces 12A and 12B. The chuck pieces 12A and 12B are provided with sandwiching pieces 12t1 and 12t2 for sandwiching and closing the parison P, respectively.

  As shown in FIG. 2, the blowing device 30 includes a blow nozzle 31 which is inserted into the parison P via one of the pair of parison chucks 10 (the first chuck 11 in the illustrated example). The blow nozzle 31 is inserted into the parison P held by the first chuck 11 in an open state by being inserted into the opening 11 s of the first chuck 11.

  The blow device 30 inserts the blow nozzle 31 into the parison P through the first chuck 11 and performs preliminary blow molding (pre-blowing step). In this preliminary blow molding step, the mold 20 having the nozzle insertion port 21 is in a state in which the left and right molds 20A and 20B are opened, and the parison P gripped by the pair of parison chucks 10 is a mold There is no restraint from 20 at all.

  The preliminary blow molding is a preliminary blow molding, in which the parison P is inflated to a certain extent, and the parison shape is controlled to correspond to the cavity shape of the mold 20. When the cavity shape is a bottle shape having a large blow ratio with respect to the parison P before blow molding, a blow ratio of a certain degree can be obtained by this preliminary blow molding. Further, in the case where the shape of the cavity is a flat bottle, the blowing air flow is adjusted so as to obtain a swelling matched to the shape by preliminary blow molding.

  As shown in FIG. 3, the mold 20 (the molds 20A and 20B) sandwiches the parison P subjected to the preliminary blow molding. That is, in a state in which the blow nozzle 31 is inserted through the first chuck 11 into the parison P held by the pair of parison chucks 10, the mold 20 holds the parison P. Since the height of the mold 20 is set within the interval (H) of the pair of parison chucks 10, when clamping the mold 20, the pair of parison chucks 10 is disposed on the upper and lower sides of the mold 20 .

  After the mold 20 is clamped, the blow device 30 performs mold-clamping blow molding in order to obtain a molded article having a shape corresponding to the cavity 22 of the mold 20 (mold-clamping blow-molding process). Here, after performing the above-described preliminary blow molding, the blow nozzle 31 holds the mold 20 inserted into the opening 11 s of the first chuck 11 and clamps the mold 20. The pre-blow molding and the mold-clamping blow molding may be performed continuously without interruption, or after the pre-blow molding, the blow molding may be temporarily stopped and then the mold-clamping blow molding may be performed.

  FIG. 4 shows a series of operations of the blow molding apparatus and the blow molding method according to an embodiment of the present invention. FIG. 4A shows a parison gripping step. In this process, the parison P discharged from the extrusion die 40 is gripped by the pair of parison chucks 10 (the first chuck 11 and the second chuck 12) at upper and lower two places. In the illustrated example, before the discharged parison P is gripped by the pair of parison chucks 10, the parison P is held and stabilized by the pair of holding chucks 50 provided with the parison cutters 51.

  FIG. 4 (b) shows a preliminary blow molding process. After the pair of parison chucks 10 grips the parison P, the parison cutter 51 provided in the holding chuck 50 operates to separate the parison P from being continuously discharged from the extrusion die 40. Then, the blow nozzle 31 is inserted into the parison P held by the pair of parison chucks 10 via one of the pair of parison chucks 10 (first chuck 11).

  Here, the pair of parison chucks 10 moves in a direction intersecting the discharge direction (vertical direction) of the parison P while holding the parison P after the parison cutter 51 is operated to separate the parison P. By this, the opening 11s of the first chuck 11 is opened, and the blow nozzle 31 is inserted therein. Thereafter, preliminary blow molding of the parison P is performed by the blow nozzle 31.

  FIG. 4C shows a mold clamping blow molding process. In this process, the mold 20 holds the parison P between the pair of parison chucks 10, and the parison P held by the mold 20 is subjected to mold clamping blow molding by the blow nozzle 31. During the period from FIG. 4 (b) to FIG. 4 (c), the blow nozzle 31 remains inserted into the parison P via the first chuck 11, and mold clamping blow molding ends from the start of preliminary blow molding. Until then, the pressure in the parison P is not released to the atmosphere.

  According to such a blow molding apparatus and blow molding method, preliminary blow molding can be performed in a state where the parison P is gripped by the pair of parison chucks 10 and without being restrained by the mold 20. As a result, preliminary blow molding with a high degree of freedom can be performed, and the molding quality can be improved not only for the bottle shape having a large blow ratio but also for various shapes such as flat bottles.

  Further, since the mold-clamping blow molding can be performed as it is with the blow nozzle 31 inserted in the parison P in order to perform the preliminary blow-molding, the preliminary blow-molding and the mold-clamping blow molding can be performed continuously. This makes it possible to obtain high forming quality compared to the prior art in which the parison is divided after pre-blowing and the blow pins are inserted.

  Further, the parison P discharged from the extrusion die 40 can be gripped by the pair of parison chucks 10 and supplied to the mold 20, and the molded product after mold opening can be gripped by the pair of parison chucks 10 and taken out. Therefore, the supply of the parison P to the mold 20 and the handling of the molded article after mold opening can be freely controlled.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and changes in design etc. within the scope of the present invention are not limited. Are included in the present invention.

10: parison chuck, 11: first chuck, 12: second chuck,
11A, 11B, 12A, 12B: chuck pieces,
11t1, 11t2: Recess, 11s: Opening, 12t1, 12t2: Clamping piece,
20: Mold, 20A, 20B: Model body, 21: Nozzle insertion port, 22: Cavity,
30: blow device, 31: blow nozzle, 40: extrusion die,
50: Holding chuck, 51: parison cutter, P: parison,

Claims (2)

A pair of holding chucks provided with a parison cutter and holding the discharged parison,
A pair of parison chucks that hold a parison at two upper and lower positions inside the pair of holding chucks ;
A mold for holding the parison cut by the parison cutter between the pair of parison chucks;
A blow device for inserting a blow nozzle into the parison through one of the pair of parison chucks;
The pair of parison chucks are disposed outside the mold, and one grips the parison in an open state, and the other occludes and grips the parison,
The blow molding apparatus performs preliminary blow molding of a parison before the mold clamps a parison, and performs mold clamping blow molding of the parison after the mold clamps a parison. A parison holding step of holding the discharged parison by a pair of holding chucks equipped with the parison cutter;
A parison holding step of holding a parison between the pair of holding chucks by the pair of parison chucks at upper and lower two places;
After the parison is cut by the parison cutter, a blow nozzle is inserted into the parison through one of the pair of parison chucks, and the parison gripped by the pair of parison chucks is blow molded by the blow nozzle. Forming process,
By placing the pair of parison chuck on the outside of the mold, to hold the said gripped by a pair of parison chuck parison by the mold, the parison is sandwiched by the molds, blow molding by the blow nozzle And a mold-clamping blow molding process.

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