JP2016078400A - Press blow molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press blow molding apparatus which can adjust thickness deviation of a parison without moving an extrusion die.SOLUTION: An extrusion head 1 includes: a thickness deviation adjustment ring 8 and an extrusion die 7 housed in a recessed portion 6a; a holder 10 for restraining the ring 8 and the die 7; and a core 9 which is inserted into the thickness deviation adjustment ring 8 and the extrusion die 7 and forms a resin path 11. Four adjustment bolts 14a to 14d are provided at an angle phase of 90 degrees in the periphery of the thickness deviation adjustment ring 8. The respective adjustment bolts 14a to 14d come in contact with the outer peripheral surface of the thickness deviation adjustment ring 8. The thickness deviation adjustment ring 8 is displaced in a radial direction according to forward/backward movements based on the rotation operation of each of the adjustment bolts 14a to 14d, and accordingly the thickness of a parison is adjusted.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an apparatus for press blow molding, which is one of blow molding methods, and more particularly to an improvement in a mechanism for adjusting the uneven thickness of a parison in a press blow molding apparatus.

  Blow molding methods (hollow molding method or blow molding method) include direct blow molding method, injection blow molding method, sheet molding method, etc., and molding positioned between direct blow molding method and injection blow molding method. There is a press blow molding method.

  In this press blow molding method, as described in Patent Document 1, for example, when a bottle-shaped hollow molded product is molded, an injection mold in which a neck portion (mouth) of the hollow molded product is abutted with an extrusion head While the injection molding is performed and the neck part after molding is separated from the extrusion head together with the extrusion mold, the parison continuous to the neck part is extruded from the extrusion head into a tube shape, and then the parison is blow molded mold with a half structure The body part of the hollow molded product is formed in a form continuous with the neck part by sandwiching between and air blowing. According to this press blow molding method, there is an advantage that “burr” does not occur on the neck side compared to the direct blow molding method, and an injection mold as compared with an injection blow molding method for molding a preform as a preform. Is said to have the advantage of being extremely small.

  In such a press blow molding method, generally, the parison is basically extruded upward from the extrusion head, and the extrusion head has a mechanism for adjusting the uneven thickness of the parison as in the direct blow molding method. Is provided. As a typical example of this parison deviation adjusting mechanism, as described in Patent Documents 1 and 2, the four around the extrusion die that are extrapolated to the core to form the extrusion opening of the parison are described. Linear actuators are provided at equal positions, and the extrusion die is displaced in a plane perpendicular to the axis of the core according to the forward and backward movement of these actuators. It is designed to adjust the uneven thickness of the parison (thickness unevenness or unevenness in the circumferential direction of the parison).

Japanese Patent No. 2658292 JP 7-32459 A JP-A-9-99481

  As a special feature of the press blow molding method, the injection molding die for injection molding of the neck part of the hollow molded product, the extrusion head to be abutted against the injection molding die, and the blow molding die are placed on the same axis. Need to be placed. And when what was described in patent documents 2 and 3 is adopted as an uneven thickness adjustment mechanism, if an extrusion die is displaced at the time of uneven thickness adjustment, it will also adjust to the position of an injection mold or a blow molding die according to it There is a problem that the number of man-hours must be increased as the adjustment work becomes complicated.

  The present invention has been made paying attention to such a problem, and provides a structure of a press blow molding apparatus that can adjust the thickness deviation without moving an extrusion die.

  According to the present invention, an injection mold having a neck-shaped cavity of a hollow molded product to be molded and an extrusion head are arranged opposite to each other on the same axis, and blow molding with a halved structure on the axis is performed. A mold is disposed, and the injection molding die and the extrusion head are abutted with each other, and then the resin material plasticized from the extrusion port of the extrusion head to the cavity is filled with the neck portion of the molded product. The molded neck portion is separated from the extrusion head together with the injection mold, and the plasticized resin material is extruded into a tube shape from the extrusion port of the extrusion head to form a parison continuous with the neck portion. Molding and clamping the blow molding die against the injection molding die so that the parison is sandwiched in the injection molding die and in the parison By blowing compressed air is a press blow molding apparatus designed to mold the body portion of the molded article integrally with the neck portion.

  The extrusion head forms an annular resin passage by a cylindrical extrusion die and a core inserted therein, and forms an extrusion port at the tip of the resin passage. A ring-shaped thickness adjusting member that is extrapolated to the core and displaceable in the radial direction of the core is provided upstream of the outlet in the extrusion direction.

  More specifically, as described in claim 2, the extrusion head has a head body, and the head body has a diameter of the thickness adjusting member while abutting on the outer peripheral surface of the thickness adjusting member. It is assumed that an operation member for adjusting the position in the direction is provided.

  Preferably, as described in claim 3, at least three positions in the circumferential direction on the outer peripheral surface of the thickness adjusting member are provided with advancing and retracting operation members capable of moving back and forth in the radial direction of the thickness adjusting member. It is assumed that the position of the thickness adjusting member is adjusted according to the movement of the operation member.

  Moreover, when the press blow molding apparatus as described in any one of Claims 1-3 is a premise, as shown in Claim 4, the said thickness adjustment member is provided in the inner peripheral side of the said thickness adjustment member. You may provide the aperture | diaphragm | squeeze part which narrows locally the resin channel formed between a core and a core.

  Therefore, in at least the invention according to claim 1, since the uneven thickness of the parison is adjusted according to the radial displacement of the thickness adjusting member independent of the extrusion die, the extrusion die is used for adjusting the uneven thickness. No need to move.

  According to the present invention, since the thickness adjustment can be performed without moving the extrusion die, it is not necessary to adjust the position of the injection mold or the blow molding die at the time of the thickness adjustment, and the thickness adjustment operation can be performed easily and quickly. Yes.

The figure which shows 1st Embodiment of the press blow molding apparatus which concerns on this invention, and is explanatory drawing which shows a basic shaping | molding procedure. Explanatory drawing of the molded article shape | molded through the process of FIG. The expanded sectional view of the extrusion head corresponded to (C) of FIG. Sectional drawing along the AA line of FIG. Sectional drawing of a parison with uneven thickness. Sectional drawing at the time of thickness adjustment based on the displacement of a thickness adjustment ring. Sectional drawing of the parison after thickness adjustment. It is a figure which shows 2nd Embodiment of the press blow molding apparatus which concerns on this invention, and is sectional drawing of a site | part equivalent to FIG. It is a figure which shows 3rd Embodiment of the press blow molding apparatus which concerns on this invention, and is sectional drawing of a site | part equivalent to FIG.

  1 to 7 show a more specific form for carrying out the press blow molding apparatus according to the present invention. In particular, FIGS. 1 and 2 show basic molding procedures in the press blow molding apparatus, and FIG. The detailed structure of each extrusion head 1 is shown.

  And here, the example in the case of shape | molding the bellows-shaped so-called boot components as shown in FIG. 3 as the hollow molded product W is shown, and this molded product W includes a small-diameter cylindrical neck portion P1 and A bellows part P2 as a large-diameter body part continuous with the neck part P1 is provided.

  As shown in FIG. 1, the press blow molding apparatus is roughly divided into an extrusion head 1 having an upward extrusion direction, and an injection mold that can be moved up and down and disposed above the extrusion head 1 so as to face the extrusion head 1. It comprises a mold 2 and a blow mold 3 disposed above the extrusion head 1 together with the injection mold 2. The extrusion head 1, the injection mold 2 and the blow mold 3 are all arranged on the same axis, and the injection mold 2 is placed in the horizontal direction with the mandrel 4 and the mandrel 4 in between. For example, it is configured by a pair of mold elements 2a and 2b having a halved structure capable of clamping / opening operation (approaching / separating operation). Similarly, the blow molding die 3 is constituted by a pair of mold elements 3a and 3b having a halved structure capable of clamping and opening operations (approaching and separating operations) in the horizontal direction. The injection mold 2 may be configured with three or more mold elements.

  FIG. 1A shows a state in which the blow molding die 3 has been opened, and the injection molding die 2 is lowered with respect to the extrusion head 1 and is brought into contact with the extrusion head 1. . In this state, a cavity corresponding to the neck portion P1 of the molded product W is formed as a molded product shape portion space on the injection mold 2 side constituted by the pair of mold elements 2a, 2b and the mandrel 4.

  As shown in FIG. 1A, when the plasticized resin material is extruded and filled from the extrusion head 1 side to the injection mold 2, the neck portion P1 of the molded product W is first injection molded. .

  Then, as shown in FIG. 1B, when the resin material is extruded from the extrusion head 1 while the neck P1 just molded is raised together with the injection mold 2, the neck P1 continues to the neck P1. Thus, a tube-shaped parison P having a predetermined thickness is integrally formed.

  Subsequently, as shown in FIG. 1C, after the injection mold 3 is clamped so that the parison P is sandwiched between the mold elements 3a and 3b, the blow port (not shown) enters the parison P. When the compressed air is blown and the parison P is inflated and brought into close contact with the molding surface of the mold elements 3a and 3b, the shape of the molding surface of the mold elements 3a and 3b is transferred to form the neck that has been molded first. A bellows part P2 as a body part of the molded product W is formed integrally with the part P1.

  In this state, since the intermediate molded product W1 composed of the neck portion P1 and the bellows portion P2 is still connected to the resin material on the extrusion head 1 side, the injection mold 2 and the blow mold 3 are respectively While performing the mold opening operation, the intermediate molded product W1 is taken out from the injection mold 3 so as to be separated from the resin material on the extrusion head 1 side.

  Then, as shown in FIG. 2, a bellows-shaped molded product is obtained by cutting and removing the excess portion Q, which is a non-product portion region attached to the end of the bellows portion P <b> 2, of the intermediate molded product W <b> 1 with a cutter 5. W will be molded.

  3 is an enlarged cross-sectional view of the extrusion head 1 corresponding to FIG. 1C, and FIG. 4 is a cross-sectional view taken along line AA of FIG. The extrusion head 1 is roughly composed of a head body 6 that forms the main body of the extrusion head 1, an extrusion die 7, a deviation adjusting ring 8 as a thickness adjusting member, a core 9, and the like.

  A concave portion 6 a is formed at the tip of the cylindrical head body 6, and this concave portion 6 a serves as an accommodating space for the extrusion die 7 and the thickness adjusting ring 8. The extrusion die 7 is formed as a so-called stepped hollow cylindrical shape having a flange portion 7a at the base portion, and is formed as a tapered shape whose diameter gradually decreases upward at the upper end portion side of the inner peripheral surface thereof. Has been. Further, the thickness adjusting ring 8 as the thickness adjusting member is ring-shaped (annular) as the name suggests, but the inner peripheral surface 8a has a tapered surface whose diameter gradually decreases upward. ing.

  And after accommodating in the recessed part 6a so that the said thickness adjustment ring 8 and the extrusion die 7 may be piled up with the thickness adjustment ring 8 facing down, the ring-shaped holder 10 is extrapolated to the extrusion die 7, By tightening and fixing the holder 10 to the head body 6 with a bolt (not shown), the thickness adjusting ring 8 and the extrusion die 7 are fixed together in the recess 6a.

  In this case, the maximum diameter of the lower end of the inner peripheral surface 8 a of the thickness adjusting ring 8 is formed so as to coincide with the diameter of the inner peripheral surface of the head body 6, and the inner peripheral surface 8 a of the thickness adjusting ring 8. Is formed so that the minimum diameter at the upper end coincides with the maximum diameter at the lower end on the inner peripheral surface of the extrusion die 7, and therefore, the inner peripheral surface of the head body 6, the inner peripheral surface 8 a of the thickness adjusting ring 8, and the extrusion die. The inner peripheral surfaces of 7 are smoothly continuous with each other while gradually decreasing in diameter upward.

  In addition, a stepped shaft-like core 9 is inserted in the central portion of the extrusion die 7 and the uneven thickness adjusting ring 8 so as to penetrate both. As a result, a narrow resin passage 11 is formed between the inner peripheral surface of the extrusion die 7 and the large diameter portion 9 a of the core 9, and the small diameter of the core 9 is provided below the thickness adjusting ring 8. A wide accumulator chamber 12 is formed between the portion 9b and also serving as a part of the resin passage 11. In the accumulator chamber 12, a ring piston 13 that can be moved up and down in the form of being externally inserted into the small diameter portion 9 b of the core 9 is disposed. In addition, the upper end of the resin passage 11 is opened to the outside as the extrusion port 11a, and the deviation adjusting ring 8 is disposed upstream of the extrusion port 11a in the extrusion direction when the extrusion port 11a is used as a reference. Will be.

  As shown in FIG. 4 in addition to FIG. 3, the thickness adjusting ring 8 accommodated in the recess 6a of the head body 6 is pressed and fixed by the holder 10 together with the extrusion die 7, but the inner diameter of the recess 6a is not fixed. Since the outer diameter of the thickness adjusting ring 8 is set to be small, the position of the thickness adjusting ring 8 in the radial direction can be adjusted in the recess 6a.

  More specifically, adjustment bolts 14a to 14d as pressing advance / retreat operation members are respectively arranged at the front end portion of the head body 6 in the circumferentially divided positions. Each of the adjusting bolts 14a to 14d is oriented in the diameter direction of the head body 6 while being screwed into a screw hole (female thread portion) formed in the head body 6, and the tip portion protrudes into the recess 6a. The thickness adjustment ring 8 is in contact with the outer peripheral surface. In the normal state, the thickness adjustment ring 8 is centered by evenly tightening the adjusting bolts 14a to 14d, and the head body 6, the extrusion die 7, the thickness adjustment ring 8 as shown in FIGS. And the four members of the core 9 are arranged concentrically. That is, the tightening forces of the four adjusting bolts 14a to 14d that are arranged around the unevenness adjusting ring 8 at a phase of 90 degrees and are in contact with the outer peripheral surface of the unevenness adjusting ring 8 are mutually antagonized. Thus, the uneven thickness adjusting ring 8 is positioned at a predetermined position. Here, it is assumed that each of the adjustment bolts 14a to 14d shown in FIGS.

  Therefore, according to the press blow molding apparatus configured as described above, the resin material extruded and plasticized from an unshown extruder is stored in advance so as to fill the accumulator chamber 12 including the resin passage 11.

  When the molded product W shown in FIG. 2 is blow-molded, the ring piston 13 shown in FIG. 3 is raised at a predetermined speed to extrude the resin material from the extrusion port 11a of the extrusion die 7 (A), After performing the process of (B), air blow is performed in FIG. 3C, so that the molded product W of FIG. 2 is finally molded through the intermediate molded product W1.

  In this case, as shown in FIG. 4, if the thickness adjusting ring 8 and the core 9 are concentric, the flow passage width a1 and the flow passage width b1 of the resin passage 11 formed therebetween are both equal. It becomes. On the other hand, even when the flow path width a1 and the flow path width b1 of the resin passage 11 are both equal, when the parison P shown in FIG. Depending on conditions, uneven thickness may occur in the thickness of the parison P. For example, in the cross-sectional view of the parison P shown in FIG. 4, the thickness a11 corresponding to the flow path width a1 of the resin passage 11 may be larger than the thickness b11 corresponding to the flow path width b1 (a11> b11).

  In such a case, as shown in FIG. 6, the adjusting bolt 14b is rotated in the pull-back direction, while the adjusting bolt 14d facing the adjusting bolt 14b is rotated in the pushing direction so that the thickness adjustment ring 8 is adjusted in diameter. The thickness adjustment ring 8 is positively eccentric with respect to the core 9 by being displaced in the direction. In this case, the extrusion die 7 adjacent to the thickness adjustment ring 8 is restrained by the outer peripheral surface of the flange portion 7a being in contact with the inner peripheral surface of the recess 6a as shown in FIG. The extrusion die 7 does not move following the movement of the ring 8. By thus displacing the uneven thickness adjusting ring 8 in the radial direction, the flow path width b2 is larger than the flow path width a2 of the resin passage 11 as shown in FIG. 7 (a2 <b2).

  When the parison P is pushed out in the eccentric state of the thickness adjusting ring 8 as shown in FIG. 6, the passage resistance is increased by narrowing the passage width in the portion corresponding to the passage width a <b> 2 of the resin passage 11. In the portion corresponding to the flow path width B2 of the resin passage 11, the flow path resistance is lowered by increasing the passage width. This means that the resin flow rate increases in the portion corresponding to the flow passage width a2 of the resin passage 11, while the resin flow rate decreases in the portion corresponding to the flow passage width b2 of the resin passage 11, as a result. As shown in FIG. 7, the wall thicknesses a12 and b12 of the extruded parison P approach an equivalent one (a12 = b12).

  Note that the procedure is the same as that described above even when the thickness adjustment operation is performed in the direction in which the other pair of adjusting bolts 14a and 14c is directed. In addition, it is desirable to reconfirm the tightening force of the other pair of adjustment bolts 14a, 14c or 14b, 14d as necessary when rotating the pair of opposing adjustment bolts 14b, 14d or 14a, 14c.

  As described above, according to the present embodiment, when adjusting the thickness deviation of the parison P to be extruded, the intended purpose can be achieved simply by displacing the thickness adjustment ring 8 in the radial direction. There is no need to readjust the positions of the injection mold 2 and blow mold 3. Therefore, the thickness adjustment operation can be performed very easily and in a short time.

  Here, the number of adjusting bolts 14a to 14d for adjusting the position of the thickness adjusting ring 8 shown in FIG. 4 is merely an example, and is not limited to four. In short, any mechanism may be used as long as the position of the thickness adjusting ring 8 can be adjusted by mutually competing the pushing forces of the plurality of adjusting bolts and the position adjusting thickness adjusting ring 8 can be restrained to a predetermined position. For example, one of the two adjustment bolts 14a, 14c or 14b, 14d facing each other in the diametrical direction of the thickness adjusting ring 8 may be replaced with a compression coil spring or other elastic body. it can. Further, for example, three adjustment bolts may be arranged around the uneven thickness adjusting ring 8 at a pitch of 120 degrees to adjust the position of the uneven thickness adjusting ring 8.

  FIG. 8 is a view showing a second embodiment of the blow molding apparatus according to the present invention, and shows a cross-sectional view of the same portion as FIG.

  In the second embodiment, the two adjusting bolts 24 a and 24 b as pressing and retreating operation members are directed in the radial direction of the head body 6 within a half circumference of the head body 6. A single adjustment bolt 15 as a pulling / retracting operation member is disposed between the two adjustment bolts 24a and 24b, with a 90 degree phase. The two adjusting bolts 24a and 24b as pressing and retreating operation members are screwed into screw holes (female screw portions) formed in the head body 6 as in the case of FIG. It protrudes into 6a and abuts on the outer peripheral surface of the thickness adjustment ring 8. On the other hand, a single adjustment bolt 15 as a pulling advance / retreat operation member is loosely inserted into a bolt insertion hole 17 formed in the head body 6 via a washer 16, and the tip portion is unevenly thickened. It is screwed into a screw hole (female thread portion) formed in the adjustment ring 8.

  Therefore, in the second embodiment, the single adjustment bolt 15 as the pulling advance / retreat operation member is directly screwed to the thickness adjusting ring 8, so that the advance / retreat based on the rotation operation of the adjustment bolt 15 is performed. According to the movement, the position of the thickness adjusting ring 8 is adjusted, and finally, another pair of adjusting bolts as pressing and advancing operation members so as to antagonize the pulling force of the thickness adjusting ring 8 by the adjusting bolt 15 By adjusting the pressing force of 24a, 24b, the thickness adjusting ring 8 can be positioned at a predetermined position.

  Further, the displacement direction of the thickness adjusting ring 8 according to the forward / backward movement of the adjusting bolt 15 that is rotated is basically the direction of the adjusting bolt 15, but the adjusting bolt 15 is a bolt formed on the head body 6. Since it is inserted loosely into the insertion hole 17 and has a predetermined play, the thickness adjustment is also performed in the direction orthogonal to the directing direction of the adjusting bolt 15 according to the advance and retreat of the two adjusting bolts 24a and 24b. The position of the ring 8 can be adjusted.

  In the second embodiment, the same effect as that of the first embodiment can be obtained.

  FIG. 9 is a view showing a third embodiment of the blow molding apparatus according to the present invention, and shows a cross-sectional view of the same portion as FIG. Therefore, in FIG. 9, the same reference numerals are given to the portions common to FIG. 3, and the detailed description of the common portions is omitted.

  In the third embodiment shown in FIG. 9, as is clear from comparison with FIG. 3, the inside of the thickness adjusting ring 8 that forms the resin passage 11 that also serves as the accumulator chamber 12 together with the small diameter portion 9 b of the core 9. An annular protrusion 8b is formed on the peripheral surface, and a throttle portion 18 is formed to locally narrow the resin passage 11 between the core 9 and the small diameter portion 9b.

  When the throttle portion 18 is provided inside the thickness adjustment ring 8 in this way, the degree of change in flow rate with respect to the amount of movement of the thickness adjustment ring 8 increases. Here, referring to FIG. 4, the case where the flow path widths a1 and b1 of the resin passage 11 are 3 mm and the case where it is 9 mm will be compared.

  If the flow path widths a1 and b1 are 3 mm, if the thickness adjusting ring 8 is moved 1 mm in the right direction in FIG. 4, the flow path width a2 is 2 mm and the flow path width b2 is 4 mm as shown in FIG. The ratio between the road widths a2 and b2 is 1: 2, and there is a double difference between the two.

  On the other hand, when the channel widths a1 and b1 in FIG. 4 are 9 mm, if the thickness adjustment ring 8 is moved 1 mm in the right direction in FIG. 4, the channel width a2 is 8 mm and the channel width b2 as shown in FIG. Is 10 mm, and the ratio between the channel widths a2 and b2 is 4: 5, and the difference between them is only about 25%. Therefore, the channel width a2 is 6 mm and the channel width b2 is 12 mm in order to make the difference between the channel widths a2 and b2 twice as in the case where the channel widths a1 and b1 are 3 mm. Thus, it is necessary to move the uneven thickness adjusting ring 8 by 3 mm.

  Therefore, according to the third embodiment, the same effect as that of the first embodiment can be obtained, and the throttle portion 18 is provided inside the uneven thickness adjusting ring 8 to provide a resin passage. Since the flow path width of 11 is locally narrowed, the stroke of the thickness adjusting ring 8 required for thickness adjustment can be reduced, and the operability at the time of thickness adjustment can be improved.

  Here, the molded product W shown in FIG. 2 is merely an example, and the present invention can be applied to blow molding of, for example, a bottle-shaped hollow container. In addition, depending on the particularity of the molded product, the parison may be required to have a positively uneven shape rather than a uniform thickness, and the present invention can be applied to such a case.

  Furthermore, when focusing on the automation of the position adjustment of the uneven thickness adjusting ring 8, instead of the adjustment bolts 14, 15, 24 which are operation members for the position adjustment, for example, a hydraulic type, a pneumatic type, Regardless of whether it is an electromagnetic type, an electric type or the like, it is also possible to use a direct acting actuator.

DESCRIPTION OF SYMBOLS 1 ... Extrusion head 2 ... Injection mold 2a, 2b ... Mold element 3 ... Blow mold 3a, 3b ... Mold element 6 ... Head body 7 ... Extrusion die 8 ... Uneven thickness adjustment ring (thickness adjustment member)
9 ... Core 11a ... Extrusion port 14a-14d ... Adjust bolt (advance / retreat operation member for pressing)
15 ... Adjust bolt (advance / retract operation member for tension)
18 ... Drawing parts 24a, 24b ... Adjust bolts (advancing / retracting operation members)
P1 ... Neck part P2 ... Bellows part (torso)
W ... Molded product

Claims (4)

An injection mold having a neck-shaped cavity of a hollow molded product to be molded and an extrusion head are arranged opposite to each other on the same axis, and a blow mold having a halved structure is arranged on the axis. Have been
The neck part of the molded product is injection-molded by filling the resin material plasticized from the extrusion port of the extrusion head to the cavity after abutting the injection mold and the extrusion head,
Forming a continuous parison on the neck by extruding the plastic material from the extrusion port of the extrusion head into a tube shape while separating the molded neck from the extrusion head together with the injection mold,
The blow mold is clamped against the injection mold so that the parison is sandwiched in the injection mold and compressed air is blown into the parison to integrally form the neck portion. In the press blow molding device designed to mold the body part,
The extrusion head forms an annular resin passage by a cylindrical extrusion die and a core inserted therein and forms an extrusion port at the tip of the resin passage,
A press blow characterized in that a ring-shaped thickness adjusting member that is extrapolated to the core and displaceable in the radial direction of the core is provided upstream of the extrusion port in the extrusion direction in the resin passage. Molding equipment.   The extrusion head has a head body, and the head body is provided with an operation member that adjusts the radial position of the thickness adjusting member while contacting the outer peripheral surface of the thickness adjusting member. The press blow molding apparatus according to claim 1, wherein the apparatus is a press blow molding apparatus.   An advance / retreat operation member capable of advancing / retreating in the radial direction of the thickness adjusting member is provided at at least three locations in the circumferential direction on the outer peripheral surface of the thickness adjusting member, and the thickness adjusting member according to the advance / retreat movement of each advance / retreat operation member The press blow molding apparatus according to claim 2, wherein the position is adjusted.   4. A throttle part for locally narrowing a resin passage formed between the thickness adjusting member and the core is provided on the inner peripheral side of the thickness adjusting member. The press blow molding apparatus as described in any one.

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