JP4283181B2 - Blow molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a final molded product from falling obliquely or in a turbulent posture without producing mold release resistance by slightly opening a blow split mold in the initial stage in a blow split mold opening process and subsequently completely opening the same and to prevent the damage of the final molded product or the occurrence of falling failure. <P>SOLUTION: In a blow molding method for molding the final molded product by blow molding in a state the mouth part of an intermediate molded product at least partially penetrated into the blow split mold is grasped, the blow split mold is opened over many stages to allow the final molded product to fall from the blow split mold. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a blow molding method.

  Conventionally, in an injection blow molding machine in which a step of molding a test tube preform by injection molding and a step of blow molding the preform, that is, a step of blow molding, can be performed by a single molding machine. The support for supporting the male mold for injection molding, the support member for the preform, etc. is rotated between the mold supporting apparatus for supporting the female mold for molding and the mold supporting apparatus for supporting the female mold for blow molding. It is arranged to be possible. One of the two mold support devices is a fixed platen fixed to the frame, and the other is a movable platen movable with respect to the fixed platen. Then, when injection molding is performed in a state where the mold is closed at the injection station and a test tubular preform is formed, the support is intermittently rotated 90 degrees after the mold is opened and heated at the heating station. Later, the preform is moved to a blow station, that is, a blow station, and the preform is loaded into a blow mold female mold and the mold is closed to perform blow molding. In addition, the molded product shape | molded by blow molding will be discharged | emitted outside the injection blow molding machine, if a female type | mold is divided | segmented (for example, refer patent document 1).

Therefore, injection molding and blow molding can be performed simultaneously at the injection station and the blow station in a single molding machine, and the throughput of the molded product is improved. Moreover, since injection molding and blow molding are performed by a single molding machine, the entire molding machine becomes compact and installation space can be saved.
JP-A-57-174219

  However, in the conventional injection blow molding machine, when the molded product is dropped and discharged to the outside at the blow station, the dropping operation is disturbed by being attached to one of the divided female molds, and the molded product is damaged. May end up. For example, if the mold release resistance of the left and right female molds is different on the left and right, or the mold opening speeds of the left and right female molds are different, the molded product has the larger mold release resistance. Attached to a female mold or a female mold with a slower mold opening speed, it does not fall or move laterally, so it does not fall straight down but falls diagonally or is in a distorted posture Or fall. Then, in the middle of dropping, the molded product may collide with a female mold or other member positioned below and be damaged.

  However, if the gap between the left and right female molds that have been opened is widened, or other members are not arranged around the female mold, and if a wide drop passage is provided for the molded product, damage to the molded product due to a collision will occur. Although it can be prevented to some extent, if the distance between the left and right female molds opened is widened, or if other members are placed in places other than the periphery of the female mold, the dimensions of the injection blow molding machine will increase and widen Installation space is required.

  In addition, if the drop direction of the molded product is slanted or the drop posture is disturbed, the molded product may interfere with each other and be damaged, or it may stop between the left and right female molds and cause a drop failure. End up. When a drop defect occurs, it is necessary to stop the operation of the injection blow molding machine and remove the molded product, resulting in a decrease in throughput.

  FIG. 2 is a first view showing the operation of opening a female mold in a conventional injection blow molding machine, and FIG. 3 is a second view showing the operation of opening a female mold in a conventional injection blow molding machine.

  FIG. 2 is a cross section of the female mold for blow molding in the blowing station, and shows an initial state in the mold opening process of the blowing station after the blow molding is finished. In this case, the movable split mold 101a and the movable split mold 101b constituting the blow mold female mold are in a closed state, and the final molded product 102 is a bottle-shaped or bottle-shaped bottomed container on the inner surface. Holding. However, the molded product gripping device releases the grip of the final molded product 102, and the screw split mold 103a and the screw split mold 103b attached to the slide plate 104a and the slide plate 104b of the molded product gripping device are illustrated. 2 respectively move in the vertical direction, and are located at a position away from the threaded portion of the final molded product 102. Moreover, the core part 106 provided with the extending | stretching rod 108 and the guide 107 for blowing is in the state of mold opening, moves relatively to the right direction in FIG. 2, and is from the female die for blow molding, and a molded product holding device. It is in a separated state.

  Subsequently, when the mold opening process of the blowing station further proceeds, the state shown in FIG. 3 is obtained. In this case, the blow molding female mold and the molded product gripping device are separated from each other, and the movable split mold 101a and the movable split mold 101b constituting the blow molding female mold are in the mold open state and separated from each other. ing. Here, in FIG. 3, since the mold release resistance in one movable split mold 101a is larger than that in the other movable split mold 101b, the final molded product 102 is attached to one movable split mold 101a. Therefore, in the state as shown in FIG. 3, when the final molded product 102 adheres from one of the movable split molds 101a and does not fall, or falls off the final molded product 102, the final molded product 102 is as described above. Since it falls diagonally or falls in a distorted posture, it may be damaged or a drop failure may occur.

  The present invention solves the above-mentioned conventional problems, slightly opens the blow split mold in the initial stage of the blow split mold opening process, and then completely opens the blow split mold, Release resistance does not occur, the final molded product can be prevented from falling diagonally or falling in a distorted posture, and the final molded product can be damaged or a drop failure can occur. It aims at providing the blow molding method which does not have.

Therefore, in the blow molding method of the present invention, in the blow molding method in which the final molded product is molded by performing blow molding in a state where the mouth of the intermediate molded product at least part of which has entered the blow split mold is held. The blow split mold is divided into multiple stages and the mold is opened in the first stage. The first stage of the blow split mold supports the mouth of the final molded product with a mouth split mold or / and a blow guide. The final molded product is dropped from the blow split mold.

  In another blow molding method of the present invention, after opening the first stage of the blow split mold, the mouth split mold for gripping the mouth is opened.

In still another blow molding method of the present invention, the mouth split mold is opened while the mouth of the final molded product is supported by a blow guide, and then the first stage of the blow split mold. Open the mold.

  In still another blow molding method of the present invention, the final molded product is separated from the inner surface of the blow split mold by opening the first stage of the blow split mold, and the edge of the blow split mold. Supported by

  In still another blow molding method according to the present invention, the distance between the blown blow molds that have been opened becomes larger than the diagonal dimension of the final molded product due to the final stage opening of the blow split mold.

According to the present invention, the blow molding method is a blow molding method in which the final molded product is molded by performing blow molding in a state where the mouth of the intermediate molded product at least partially entering the blow split mold is held. The blow split mold is opened in multiple stages, and the first stage of the blow split mold is a state in which the mouth of the final molded product is supported by the mouth split mold or / and the guide for blow And the final molded product is dropped from the blow split mold.

  Therefore, in the mold opening process of the blow split mold, it is possible to prevent mold release resistance and prevent the final molded product from falling obliquely or falling in a distorted posture. There will be no damage or drop failures.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a partial plan sectional view of an injection blow molding machine according to an embodiment of the present invention, and FIG. 4 is a partial vertical sectional view of an injection blow molding machine according to an embodiment of the present invention.

  1 and 4, reference numeral 10 denotes an injection blow molding machine, a fixed platen 11 as an injection mold support device fixed to a support frame (not shown), and a blow metal slidably attached to a guide member on the support frame. A movable platen 12 as a mold support device and an intermediate mold support frame 21 as an intermediate mold support device slidably attached to the guide member between the fixed platen 11 and the movable platen 12 are provided. The injection blow molding machine 10 forms a preform 61, which will be described later, as a test tubular intermediate molded product by injection molding, and a final molded product, which will be described later by blow molding, that is, blow molding. The apparatus which performs the process shape | molded in 62. In the injection blow molding machine 10, injection molding is performed at the injection station between the fixed platen 11 and the intermediate mold support frame 21, and the blow is performed at the blow station between the movable platen 12 and the intermediate mold support frame 21. Molding is performed. It is also possible to use a blowing station between the fixed platen 11 and the intermediate mold support frame 21 and an injection station between the movable platen 12 and the intermediate mold support frame 21. The final molded product 62 may have any shape. Here, the final molded product 62 is a bottle-shaped or bottle-shaped bottomed container having a small-diameter open mouth, and a male screw is provided on the outer periphery of the mouth. It is assumed that is formed.

  A fixed mold 13 as an injection mold is attached to the mold mounting surface (the left surface in FIGS. 1 and 4) of the fixed platen 11. An injection core mold 42 is disposed on the surface of the core mold frame 41 as an intermediate mold that is non-rotatably attached to the intermediate mold support frame 21 on the fixed platen 11 side. The injection core mold 42 includes a root portion 42a and a male mold portion 42b. When the fixed mold 13 and the injection core mold 42 are in close contact with each other and the mold is closed, the injection core mold 42 is interposed between the fixed mold 13 and the fixed mold 13. A cavity having the shape of the preform 61 is formed. 1 and 4 show a state where the fixed mold 13 and the injection core mold 42 are opened and the mold is opened.

  An injection device (not shown) is disposed on the back surface (the right surface in FIGS. 1 and 4) of the fixed platen 11. Here, the injection apparatus includes a heating cylinder, and a raw material hopper for charging a raw material resin such as resin pellets into the heating cylinder is attached to the heating cylinder. Further, a screw is disposed in the heating cylinder so as to be able to rotate and to advance and retreat. An injection driving device for rotating the screw in the heating cylinder and moving it forward or backward is disposed behind the heating cylinder.

  In the metering step, the screw is driven to rotate and rotate the screw to accumulate resin in front of the screw, so that the screw moves back to a predetermined position (right direction in FIGS. 1 and 4). Move to). At this time, the raw material resin supplied from the raw material hopper is heated and melted in the heating cylinder, and the screw is retracted by the pressure of the resin stored in front of the screw (left side in FIGS. 1 and 4). Subsequently, in the injection process, the nozzle at the tip of the heating cylinder is pressed against the fixed mold 13 and the injection driving device is driven to advance the screw (move leftward in FIGS. 1 and 4). As a result, the resin stored in front of the screw is injected from the tip of the nozzle and filled into a cavity formed between the fixed mold 13 and the injection core mold 42.

  A blow molding female die 58, which is a blow mold for blow molding, which will be described later, is provided on the mold mounting surface (the right side surface in FIGS. 1 and 4) of the movable platen 12. A movable split mold 14 as a movable mold to be formed is attached. The movable split mold 14 includes a drive side movable part 14a and a driven side movable part 14b, and the drive side movable part 14a and the driven side movable part 14b are laterally moved by a split mold drive cylinder device 17 as a split type drive apparatus. (Vertical direction in FIG. 1). In this case, the drive-side movable portion 14a is connected to the piston rod 17a of the split-type drive cylinder device 17, and is directly moved by the split-type drive cylinder device 17, and the driven-side movable portion 14b is connected to another drive side. It is connected to the movable part 14a and is moved in a direction facing the drive-side movable part 14a of its own set.

  The split drive cylinder device 17 is a pneumatic cylinder device, for example, and is operated by compressed air. Further, the split mold drive cylinder device 17 includes a first stage cylinder device for performing a first stage mold opening for slightly dividing the blow molding female mold 58 at an initial stage in the mold opening process, and the blow mold It is composed of a second stage cylinder device for causing the second stage mold opening to largely divide the molding female mold 58.

  A blowing guide 43 is disposed on the surface of the core mold 41 attached to the intermediate mold support frame 21 on the movable platen 12 side. The blowing guide 43 includes a root portion 43a, and an inlet of a blow molding female die 58 (see FIG. 5) as a blow split die formed by closely contacting the driving side movable portion 14a and the driven side movable portion 14b. In the state of being in close contact with the mold and closed, a blow molding space having the shape of the final molded product 62 is formed. 1 and 4 show a state where the drive side movable portion 14a and the driven side movable portion 14b of the movable split mold 14 are opened, and the movable split mold 14 and the blowing guide 43 are opened and the mold is opened. Is shown.

  A mold clamping device (not shown) is disposed on the back surface (left surface in FIGS. 1 and 4) of the movable platen 12. The mold clamping device includes a mold clamping cylinder device for driving the movable platen 12 and a support plate to which the mold clamping cylinder device is attached. The fixed platen 11 and the support plate are connected by a plurality of, for example, four tie bars, and the movable platen 12 and the intermediate mold support frame 21 move forward or backward along the tie bars (in the right direction in FIGS. 1 and 4). (Or move leftward). The fixed platen 11 is fixed to the support frame by a fixing member such as a bolt. The movable platen 12 and the intermediate mold support frame 21 slide while being supported mainly from below by the guide member.

  In the present embodiment, the mold clamping device and the drive source of the mold clamping device may be of any type, and instead of the mold clamping cylinder device, a toggle mechanism type using a toggle link is used. Alternatively, a composite system in which a link mechanism and a cylinder device are combined may be used. Also, the drive source may be a hydraulic cylinder device, or a combination of an electric motor and a ball screw.

  Further, an intermediate drive cylinder device 22 as an intermediate drive device is attached to the fixed platen 11, and an intermediate support frame 21 is attached to a connecting rod 23 connected to the piston rod of the intermediate drive cylinder device 22. ing. Then, by operating the intermediate drive cylinder device 22, the intermediate support frame 21 can be moved forward or backward with respect to the fixed platen 11. Thereby, the intermediate mold support frame 21 can be moved with respect to the stationary platen 11, and the injection molding and blow molding are performed by performing mold closing, mold clamping, and mold opening at separate timings at the injection station and the blowing station. It can be carried out.

  In the present embodiment, the intermediate support frame 21 has a substantially gate shape, and a lower end portion is slidably attached to the guide member, and the left and right leg portions extending in the vertical direction, and the leg portions A top plate portion extending in the lateral direction connecting the upper end portions. The core mold 41 is disposed between the left and right legs. Here, the core mold 41 is fixed to a cylindrical support column 47 attached through the left and right legs. That is, the core mold 41 is non-rotatably attached to the intermediate mold support frame 21.

  A rotating frame 31 as a gripping frame is rotatably attached to the left and right outer sides of the intermediate support frame 21 in the support column 47. In the state shown in FIGS. 1 and 4, columnar guide bars 33 extending forward and rearward are attached to the front and rear sides (right and left sides in FIGS. 1 and 4) of the rotating frame 31. Yes. The number of the guide bars 33 can be arbitrarily set. In the example shown in FIGS. 1 and 4, two guide bars 33 are attached to the left and right rotating frames 31 in the front-rear direction. The guide bar 33 has a gripping frame 32 that supports a molded product gripping device 52 to be described later for gripping the outer periphery of the mouth of the preform 61 as an intermediate molded product in the axial direction of the guide bar 33. The guide bar 33 is slidably attached to the distal end portion 33a of the guide bar 33 so that it can be locked and released. In the state shown in FIGS. 1 and 4, the grip frame 32 is locked to the distal end portion 33a of the guide bar 33 by the grip frame engaging portion 32a, and does not slide in the axial direction of the guide bar 33. Yes. Note that when the engagement between the gripping frame engaging portion 32 a and the tip end portion 33 a is released, the gripping frame 32 is released and can slide in the axial direction of the guide bar 33.

  The gripping frame engaging portion 32a is releasably engaged with a distal end portion of an ejection side engaging / disengaging member (not shown) attached to the fixed platen 11, and is operated by the distal end portion of the ejection side engaging / disengaging member, The tip 33a of the guide bar 33 is engaged or disengaged. Further, the grip frame engaging portion 32a is releasably engaged with a tip portion of a blow side engaging / disengaging member (not shown) attached to the movable platen 12, and is operated by a tip portion of the blow side engaging / disengaging member. Thus, the distal end portion 33a of the guide bar 33 is engaged or disengaged.

  An electric motor 34 is attached to one leg portion of the intermediate support frame 21 as a drive source for rotating the rotary frame 31. Then, by operating the electric motor 34, the rotary frame 31 rotates around the support column 47.

  On the upper outer surface and lower outer surface of the core mold 41, grip release as a drive source for driving a grip release member (not shown) for operating the molded product gripping device 52 to release the grip state Each drive device 45 is attached. The grip release driving device 45 may be a hydraulic cylinder device or a combination of an electric motor and a ball screw. Here, it is a pneumatic cylinder device, and the pneumatic cylinder A description will be given assuming that the grip release member is attached to the piston rod of the apparatus. When the grip release driving device 45 is actuated, the grip release member is advanced and retracted.

  By the way, the extending rod 44 is attached to the blowing guide 43 so as to protrude from the root portion 43a. And on the outer surface on the upper side and the lower outer surface of the core mold 41, there are respectively a stretching rod driving device 46 as a driving source for operating the stretching rod 44 to protrude from the root portion 43a. Is attached. The drawing rod drive device 46 may be a hydraulic cylinder device or a combination of an electric motor and a ball screw, but here, it will be described as a pneumatic cylinder device. When the drawing rod driving device 46 is operated, the connecting plate 46a connected to the piston rod of the drawing rod driving device 46 moves, and the drawing rod 44 having the root portion attached to the connecting plate 46a is moved. It protrudes and the said preform 61 is extended. That is, in the present embodiment, the stretch rod 44 protrudes into the preform 61, and the preform 61 is finally blown by stretch blow molding in which high pressure air is blown while the preform 61 is stretched. The molded product 62 is molded. In this case, a blowing guide 43, an extending rod 44, or an air flow path (not shown) for supplying high pressure air for blow molding, an air ejection hole (cutting), and the like are formed between them.

  If necessary, the preform 61 can be formed into the final molded product 62 by blow molding in which high-pressure air is blown without projecting the stretching rod 44. In this case, the stretching rod 44, the stretching rod driving device 46, etc. can be omitted. It should be noted that power is supplied to piping for supplying high-pressure air as working fluid to the grip-release driving device 45 and the stretching rod driving device 46, piping for supplying high-pressure air for blow molding, and various devices. A signal line or the like for transmitting a signal from an electric wire, a sensor, or the like can be disposed so as to pass through the hollow support column 47.

  The injection blow molding machine 10 has a control device (not shown). The control device includes all operations of the injection blow molding machine 10 including the operations of the injection device, mold clamping device, intermediate mold drive cylinder device 22, electric motor 34, grip release drive device 45, draw rod drive device 46, and the like. To control the operation. In addition, the control device may be configured integrally with another control device such as a control device of a molded product take-out device, or among a plurality of control systems constructed in a large computer. There may be one.

  Next, the configuration of each part of the injection blow molding machine 10 will be described in detail.

  As shown in FIGS. 1 and 4, a female mold portion 51 as an injection mold is attached to a mold mating surface of the fixed mold 13, that is, a parting surface, by a cavity plate 13e. There may be a single female mold part 51 or a plurality of female mold parts 51, but in this embodiment, two rows of six rows in the vertical direction are formed, and twelve female mold parts 51 are formed. Is attached to the fixed mold 13. In this case, six blow molding female molds 58 formed by the movable split mold 14 attached to the mold mounting surface of the movable platen 12 at the blowing station are also arranged in the vertical direction, like the female mold part 51. Two rows are formed.

  In the fixed mold 13, a nozzle touch part 13a to which the tip of the nozzle of the heating cylinder is pressed, a sprue 13b as a resin flow path extending from the nozzle touch part 13a, and a resin flow branched from the sprue 13b A runner 13 c as a path and a hot runner nozzle 13 d formed at the tip of the runner 13 c and communicating with the interior of each female mold 51 are formed. Thereby, the resin injected from the tip of the nozzle of the heating cylinder passes through the sprue 13b, the runner 13c, and the hot runner nozzle 13d, and is formed between each female mold part 51 and the corresponding male mold part 42b. Filled in the cavity. The injection core molds 42 are formed in two rows at positions corresponding to the respective rows of the female mold portions 51, and the root portion 42a and the male mold portion 42b are formed at positions corresponding to the respective female mold portions 51 of the respective injection core dies 42. Is arranged. That is, there are twelve root portions 42a and twelve male portions 42b.

  A molded product gripping device 52 is attached to the gripping frame 32. The molded product gripping device 52 includes a screw split mold 52a as a mouth split mold, and a slide plate 52b to which the screw split mold 52a is attached. In the screw split mold 52a, two rows of six rows in the vertical direction are formed at positions corresponding to the female mold portions 51, and twelve screw split molds 52a are attached to the grip frame 32. ing. Then, the screw split mold 52a is formed with a spiral groove for forming a male screw on the inner peripheral surface, and is fitted into the vicinity of the inlet of the female mold portion 51. A cavity corresponding to the mouth of the preform 61 is formed between the portion 42b. Thereby, a male screw is formed on the outer periphery of the mouth of the preform 61.

  The screw split mold 52a has a configuration that can be divided in the lateral direction (vertical direction in FIG. 1), and the split part of each screw split mold 52a is attached to the split part of the slide plate 52b. It has been. The slide plate 52b extends in the vertical direction (perpendicular to FIG. 1) and is attached to the gripping frame 32. Each of the slide plates 52b has a configuration that can be divided in the horizontal direction. The split portion is attached to the grip frame 32 so as to be slidable in the lateral direction. And the half part of each slide plate 52b is urged | biased by the urging members, such as a spring member, in the center direction, and couple | bonds together. Thereby, the half part of each screw split mold 52a is also urged in the center direction so as to be coupled to each other.

  A grip release driven member 52c is attached to the vicinity of the upper and lower ends of each slide plate 52b. The grip release driven member 52c has a configuration that can be divided in the lateral direction, and a half portion of each grip release follower member 52c is attached to a half portion of the slide plate 52b. When the halved portions of the slide plate 52b are urged in the central direction and coupled to each other, the halved portions of the grip release follower member 52c are also coupled to each other, and a wedge (as shown in FIG. A wedge-shaped notch is formed. The notch is at a position corresponding to the protrusion member of the grip release member. When the grip release member moves forward, the protrusion member enters the notch and the grip release follower member 52c is pushed and spread in the lateral direction. Yes. As a result, the halved portion of each slide plate 52b and the halved portion of each screw split mold 52a are also spread and divided in the lateral direction, so that after the blow molding is completed at the blowing station, the final molded product The 62 mouths can be released.

  The left and right rotating frames 31 that support the guide bar 33 to which the gripping frame 32 is attached are connected to the support column 47 via a bearing member 47a composed of a ball bearing, a roller bearing, and the like as shown in FIG. It is rotatably attached to the outer periphery. An annular driven gear 31a is attached to the side surface of one rotating frame 31, and a drive gear 34b attached to the rotating shaft 34a of the electric motor 34 meshes with the driven gear 31a. Accordingly, the rotary frame 31 can be rotated around the support column 47 by operating the electric motor 34.

  The core mold 41 has a substantially rectangular parallelepiped shape with a part of the wall surface opened, and a connecting plate 46a is disposed inside the core mold frame 41 so as to be able to advance and retract toward the movable split mold 14 side. The connection plate 46 a is attached to the extending rod driving device 46, with a part near the upper and lower ends projecting from the upper outer surface and the lower outer surface of the core mold 41. Moreover, the base part of each extending | stretching rod 44 is attached to the connection board 46a, and each extending | stretching rod 44 can be protruded simultaneously. The extending rods 44 are disposed at positions corresponding to the respective blow molding female molds 58 formed by the movable split mold 14 and form two rows of six rows in the vertical direction.

  In the present embodiment, the drive side movable portion 14a and the driven side movable portion 14b of the movable split mold 14 are attached to the mold attachment surface of the movable platen 12 so as to be slidable in the lateral direction (vertical direction in FIG. 1). . In this case, the left and right sets of drive-side movable parts 14 a are connected to the piston rod 17 a of the split-type drive cylinder device 17, and are moved directly in the lateral direction by the split-type drive cylinder device 17. The left and right sets of driven side movable parts 14b are connected to the other set of drive side movable parts 14a by a connecting member 14d, and are moved in a direction opposite to the own set of drive side movable parts 14a. Then, by operating the left and right split mold drive cylinder devices 17 in synchronism, the drive-side movable part 14a and the driven-side movable part 14b in each set are moved and coupled in opposite directions, and the blow mold female mold 58 can be formed.

  When the injection blow molding machine 10 is closed at the injection station and the blow station, the intermediate mold support frame 21 comes into contact with the fixed platen 11 and the movable platen 12 comes into contact with the intermediate mold support frame 21. In this case, the engagement between the gripping frame engaging portion 32a and the tip end portion 33a of the guide bar 33 is released, and the gripping frame 32 in the injection station and the blowing station slides in the axial direction of the guide bar 33, and the core Contact the formwork 41.

  In the injection station, each male part 42 b enters each female part 51 attached to the fixed mold 13. Further, the screw split mold 52a in which the half parts are coupled to each other is sandwiched between the female mold part 51 and the injection core mold 42 in a state of being fitted in the vicinity of the inlet of the female mold part 51. ing. Thereby, a cavity is formed between the inner surface of the female mold part 51 and the split part for screw 52a and the outer surface of the male mold part 42b, and the preform is formed by filling the cavity with the resin. In the present embodiment, the preform 61 is a substantially test tube elongated bottomed container, and a male screw is formed on the outer periphery of the opening mouth by the inner surface of the split mold 52a for screwing, and at the boundary of the mouth. The flange portion is formed by a gap between the screw split mold 52 a and the female mold portion 51.

  In the blowing station, the drive side movable portion 14a and the driven side movable portion 14b are combined to form the blow molding female die 58. In this case, the drive-side movable portion 14a and the driven-side movable portion 14b are coupled from the left and right, and the inner surface of the blow molding female mold 58 has the shape of a bottle-shaped or bottle-shaped bottomed container.

  The screw split mold 52a in a state of gripping the preform 61 is pressed against the opening of the blow molding female mold 58 formed by the driving side movable section 14a and the driven side movable section 14b. Therefore, the collar portion of the preform 61 is pressed against the outer surface of the opening of the blow molding female mold 58, and the portion ahead of the collar portion enters the blow molding female mold 58. When the stretching rod driving device 46 is operated in this state, the stretching rod 44 protrudes toward the inner side of the blow molding female mold 58 and enters the inside of the preform 61 to blow the preform 61. It extends toward the back side of the female die 58 for molding. At the same time, high pressure air is blown into the preform 61 through an air flow path (not shown), whereby the preform 61 is expanded and pressed against the inner surface of the blow molding female mold 58. Thereby, the bottle-shaped or bottle-shaped bottomed container which has the shape of the inner surface of this female mold 58 for blow molding can be shape | molded.

  Next, the operation of the injection blow molding machine 10 having the above configuration will be described.

  FIG. 5 is an enlarged plan view of an essential part of a blow station of an injection blow molding machine according to an embodiment of the present invention, and is a first view showing the operation. FIG. 6 is a diagram of the injection blow molding machine according to the embodiment of the present invention. FIG. 7 is an enlarged plan sectional view of the main part of the blowing station and shows the operation; FIG. 7 is an enlarged plan sectional view of the main part of the blowing station of the injection blow molding machine in the embodiment of the present invention. 3 and FIG. 8 are cross-sectional views taken along the line AA of FIG. 7 in the embodiment of the present invention, and FIG. 9 is an enlarged plan cross-sectional view of the main part of the injection station of the injection blow molding machine in the embodiment of the present invention. FIG. 10 is an enlarged plan sectional view of the main part of the blow station of the injection blow molding machine in the embodiment of the present invention, and FIG. Blow step of injection blow molding machine in an embodiment of the invention FIG. 6 is an enlarged plan sectional view of the main part of the operation, and FIG. 12 is an enlarged vertical sectional view of the main part of the injection station of the injection blow molding machine in the embodiment of the present invention. It is a figure which shows an example.

  In this case, in one molding cycle, the number of preforms 61 equal to the number of female mold parts 51, for example, 12 preforms 61 are molded by injection molding at the injection station, and the previous molding cycle is performed at the blowing station. The 12 preforms 61 molded at the injection station are blow-molded, and 12 final molded products 62 are molded.

  First, as shown in FIGS. 1 and 4, from a state where the mold is opened at the injection station and the blowing station, a mold clamping device (not shown) is operated to start the mold closing. Thus, the movable platen 12 moves from the mold open state toward the mold closed state, that is, moves closer to the fixed platen 11. Then, while the movable platen 12 moves from the mold open state toward the mold close state, the intermediate mold drive cylinder device 22 is operated, and the intermediate mold support frame 21 is moved from the mold open state to the mold closed state. Toward the stationary platen 11.

  Further, when the movable platen 12 moves from the mold open state toward the mold closed state, the intermediate mold support frame 21 approaches the fixed platen 11, so that it is attached to the side surface of the rotating frame 31 on the fixed platen 11 side. The holding frame engaging portion 32 a of the holding frame 32 engaged with the leading end portion 33 a of the guide bar 33 is in contact with the leading end portion of the ejection side engaging / disengaging member attached to the fixed platen 11. Thereby, the engagement between the grip frame engaging portion 32a and the tip end portion 33a of the guide bar 33 is released, and the lock between the grip frame 32 and the guide bar 33 is released.

  Similarly, while the movable platen 12 moves from the mold open state toward the mold closed state, the intermediate mold support frame 21 approaches the movable platen 12, so that the side surface of the rotary frame 31 on the movable platen 12 side. The grip frame engaging portion 32 a of the grip frame 32 engaged with the tip portion 33 a of the attached guide bar 33 comes into contact with the tip portion of the blowing side engaging / disengaging member attached to the movable platen 12. Thereby, the engagement between the grip frame engaging portion 32a and the tip end portion 33a of the guide bar 33 is released, and the lock between the grip frame 32 and the guide bar 33 is released. The screw split mold 52a in the gripping frame 32 grips twelve preforms 61 molded at the injection station in the previous molding cycle.

  Further, while the movable platen 12 moves from the mold open state to the mold closed state, the split mold drive cylinder device 17 is operated, and the drive side movable portion 14a and the driven side movable portion 14b are moved in the lateral direction ( The blow mold female mold 58 is formed by moving in the vertical direction in FIG. Thus, as shown in FIG. 5, the mouth of the preform 61 is held in the opening of the blow molding female mold 58 formed by the driving side movable portion 14a and the driven side movable portion 14b. The split mold 52a for screw is pressed. Further, the tip end portion 43 b of the base portion 43 a of the blowing guide 43 is fitted into the mouth portion of the preform 61. Therefore, the flange part of the preform 61 is pressed against the outer surface of the opening part of the blow-molding female mold 58, and the part ahead of the collar part enters the blow-molding female mold 58. The state shown in FIG. 5 is a state in the middle of the extension rod 44 protruding toward the back side of the blow molding female mold 58, as will be described later.

  When the movable platen 12 is in the mold closed state, the mold closing is completed at the injection station and the blowing station. In this case, since the holding frame 32 at the injection station and the blowing station is unlocked from the guide bar 33, the gripping frame 32 is pushed by the injection side engaging / disengaging member and the tip of the blowing side engaging / disengaging member, and the shaft of the guide bar 33 It slides in the direction and is in contact with the core formwork 41.

  In this case, at the injection station, each male part 42 b enters each female part 51 attached to the fixed mold 13. Further, the screw split mold 52a in which the half parts are coupled to each other is sandwiched between the female mold part 51 and the injection core mold 42 in a state of being fitted in the vicinity of the inlet of the female mold part 51. ing. Thereby, a cavity is formed between the inner surface of the female mold part 51 and the split mold 52a for screw and the outer surface of the male mold part 42b. Further, in the blowing station, the flange portion of the preform 61 is pressed against the outer surface of the opening portion of the blow molding female mold 58, and the portion ahead of the flange portion enters the blow molding female mold 58.

  Subsequently, an injection process is performed at the injection station, the nozzle at the tip of the heating cylinder is pressed against the nozzle touch portion 13a of the fixed mold 13, and the resin is injected from the tip of the nozzle. Then, the injected resin passes through the sprue 13b, the runner 13c, and the hot runner nozzle 13d, and is filled into a cavity formed between the female mold part 51 and the corresponding male mold part 42b. In addition, even after the filling of the resin is completed, the closed state is continued and the resin in the cavity is cooled.

  Further, blow molding is performed at the blowing station, the stretching rod driving device 46 is operated, and the stretching rod 44 projects toward the back side of the blow molding female mold 58. Thus, the preform 61 enters the inside of the preform 61 and is stretched toward the back side of the blow molding female mold 58. At the same time, the preform 61 is expanded by blowing high-pressure air into the preform 61 from the blowing guide 43, the extending rod 44, or an air flow path, an air blowing hole (not shown) formed therebetween. Then, it is pressed against the inner surface of the female mold 58 for blow molding. Thereby, as shown in FIG. 6, a bottle-shaped or bottle-shaped bottomed container having the shape of the inner surface of the blow-molding female mold 58 can be molded as the final molded product 62. In addition, when extending | stretching is complete | finished, the extending | stretching rod 44 will be returned to the original position from the protruded state.

  When blow molding is completed, the mold clamping force (force to press the movable platen 12 in the right direction in FIGS. 1 and 4) applied to the movable platen 12 by the mold clamping device is released. Note that the time from the start to the end of blow molding varies depending on the material, size, thickness, etc. of the preform 61 and the final molded product 62, but here it is assumed to be about 0.2 seconds. explain. At this time, since the intermediate mold support frame 21 is kept in the mold closed state with the fixed mold 13 by the intermediate mold drive cylinder device 22, the mold closed state is maintained in the injection station, and the resin in the cavity is cooled. Is continuing. The force generated by the intermediate mold drive cylinder device 22 is weaker than the mold clamping force generated by the mold clamping device, but is sufficient to maintain the mold closed state when the resin in the cavity is cooled. It has become.

  Here, since the mold clamping force applied to the movable platen 12 is released, the movable platen 12 moves slightly away from the core mold frame 41. 43 and the split part 52a for screws of the molded product gripping device 52 are slightly separated from each other, and a slight gap α is generated between the blowing guide 43 and the split part 52a for screws as shown in FIG. Α is a dimension of about 1 to 2 [mm].

  Also, the first stage cylinder device of the split mold drive cylinder device 17 is operated to perform the first stage mold opening that slightly divides the blow molding female mold 58, and the drive side movable portion 14a and the driven side movable section are moved. The portion 14b slightly moves in the lateral direction (vertical direction in FIG. 1), and as shown in FIG. 7, a slight gap β is generated between the driving side movable portion 14a and the driven side movable portion 14b. In addition, (beta) is a dimension about 1-2 [mm]. In this case, the mold clamping force applied to the movable platen 12 is released, so that the split mold 52a and the slide plate 52b of the molded product gripping device 52, the drive side movable portion 14a, and the driven side movable portion 14b. Since the adhesion force decreases, the driving side movable portion 14a and the driven side movable portion 14b can be moved in the lateral direction.

  At this time, since the screw split mold 52a holds the mouth of the final molded product 62, that is, the final molded product 62 is supported by the screw split mold 52a, the driving side movable portion 14a and the driven side movable portion are movable. Even if the portion 14b moves, the final molded product 62 does not move. Therefore, as shown in FIG. 7, a gap is generated between the inner surface of the blow molding female mold 58 formed by the driving side movable portion 14 a and the driven side movable portion 14 b and the final molded product 62. That is, the final molded product 62 is released from the drive side movable portion 14a and the driven side movable portion 14b. However, since the gap β generated between the drive-side movable portion 14a and the driven-side movable portion 14b is small, the drive-side movable portion 14a and the driven-side movable portion 14b have an edge portion as shown in FIG. B is in a state of slightly contacting the outer surface of the final molded product 62. As shown in FIG. 8, the cross-sectional shape of the blow molding female mold 58 in the driving side movable portion 14a and the driven side movable portion 14b is a semicircle, and the semicircle, the driving side movable portion 14a, and the driven side movable portion Four edge portions B which are boundaries with the mating surface of 14b are in contact with the outer surface of the final molded product 62 having a circular cross-sectional shape.

  Subsequently, while the movable platen 12 further moves away from the core mold 41, the grip release driving device 45 is operated, and a grip release member (not shown) moves forward, that is, moves toward the movable platen 12, The protruding member of the grip release member enters the notch of the grip release driven member 52c of the molded product gripping device 52 attached to the grip frame 32, and pushes the halved portion of the grip release driven member 52c laterally. As a result, the halved portion of each slide plate 52b of the molded product gripping device 52 and the halved portion of each screw split mold 52a are also spread laterally and divided to open the mold, as shown in FIG. As described above, the grip of the mouth of the final molded product 62 is released. At this time, since the distal end portion 43b of the base portion 43a of the blowing guide 43 is maintained in the state where it has entered the mouth portion of the final molded product 62, the final molded product 62 is connected to the distal end portion 43b and the drive side. It is supported by the movable portion 14a and the edge portion B of the driven-side movable portion 14b so as not to move.

  Subsequently, when the movable platen 12 further moves in the direction away from the core mold 41, the root portion 43 a of the blowing guide 43 retreats from the mouth portion of the final molded product 62 as shown in FIG. 10. Therefore, the final molded product 62 is supported by the edge portion B of the driving side movable portion 14a and the driven side movable portion 14b.

  Subsequently, when the movable platen 12 further moves in the direction away from the core mold 41 and a sufficient space is formed between the drive side movable unit 14a and the driven side movable unit 14b and the molded product gripping device 52, the split platen 12 is split. The second-stage cylinder device of the mold drive cylinder device 17 is operated, and the second-stage mold opening is performed to divide the blow-molding female mold 58 largely. As a result, the drive side movable portion 14a and the driven side movable portion 14b further move in the lateral direction, and as shown in FIG. 11, the distance between the drive side movable portion 14a and the driven side movable portion 14b is at least the final molded product. It becomes larger than the outer diameter of 62. Therefore, the final molded product 62 falls off the driving side movable portion 14a and the driven side movable portion 14b (moves in a direction perpendicular to FIG. 11).

  In this case, since the first stage operation for slightly dividing the female mold 58 for blow molding has already been performed, the final molded product 62 adheres to both the driving side movable portion 14a and the driven side movable portion 14b. Not. In addition, after the first stage operation is performed until the second stage operation is performed in which the blow molding female mold 58 is largely divided, the final molded product 62 includes the driving side movable portion 14a and the driven side movable portion. Since it is supported by the edge B etc. of 14b, the position and attitude | position of the final molded product 62 are stable. Therefore, when the final molded product 62 is detached from the driving side movable portion 14a and the driven side movable portion 14b, the final molded product 62 falls straight downward while maintaining a stable posture. And the final molded product 62 is discharged | emitted below the injection blow molding machine 10, and is accommodated in the accommodating apparatus which is not shown in figure.

  Then, when the removal of the final molded product 62 is completed, the intermediate mold drive cylinder device 22 is operated, and the intermediate mold support frame 21 moves away from the mold closed state to the mold open state, that is, away from the fixed platen 11. Move to. At this time, the resin in the cavity is sufficiently cooled, and the preform 61 is molded. The time from the start of injection molding until the resin is sufficiently cooled varies depending on the material, size, thickness, etc. of the preform 61, but here it is assumed to be about 6.0 seconds. explain. Since the core mold 41 moves together with the intermediate mold support frame 21, the male mold part 42 b is pulled out from the female mold part 51 attached to the fixed mold 13. In addition, since the gripping frame engaging portion 32a of the gripping frame 32 at the injection station is engaged with the tip of the injection side engaging / disengaging member, even if the intermediate mold support frame 21 moves toward the mold open state, The gripping frame 32 slides in the axial direction of the guide bar 33, and the screw split mold 52 a maintains a state where it is fitted in the vicinity of the inlet of the female mold part 51. When the grip frame 32 reaches the distal end portion 33a of the guide bar 33, the grip frame engaging portion 32a releases the engagement with the distal end portion of the ejection side engaging / disengaging member, and engages with the distal end portion 33a of the guide bar 33. As a result, the grip frame 32 and the guide bar 33 are locked.

  Subsequently, when the intermediate mold support frame 21 further moves away from the fixed platen 11, the gripping frame 32 also moves, so that the screw split mold 52 a is pulled out from the female mold part 51. In this case, the half portion of the screw split mold 52a is urged in the central direction by the urging member and is coupled to each other, so that the mouth portion of the preform 61 is gripped. In this case, the screw split mold 52a includes a spiral groove for forming a male screw on the inner peripheral surface, and a male screw is formed in the mouth portion of the preform 61 by the spiral groove, and the spiral groove and the male screw are associated with each other. Match. Further, even when a force is applied in the axial direction of the preform 61, the grip of the split portion 52a for the screw on the mouth portion of the preform 61 does not come off. Therefore, even if the preform 61 is attached to the inner surface of the female mold part 51, the preform 61 is reliably pulled out from the female mold part 51 by the screw split mold 52a.

  As a result, the gripping frame 32 at the injection station reaches a position away from the fixed mold 13 with the screw split mold 52 a gripping all twelve preforms 61. In this case, the distance from the center of the support column 47 to the fixed mold 13 and the distance from the center of the support column 47 to the movable split mold 14 are substantially equal to each other, and the rotary frame 31 rotates around the support column 47. However, the distance is such that the gripping frame 32 is not in contact with either the fixed mold 13 or the movable split mold 14.

  Subsequently, the electric motor 34 is operated to rotate the rotating frame 31 around the support column 47. As a result, the gripping frame 32 with the screw split mold 52a gripping the preform 61 moves from the injection station to the blowing station, and the other gripping frame 32 moves from the blowing station to the injection station.

  When the rotation of the rotary frame 31 is completed, the mold is opened at the injection station and the blowing station as in the beginning. Thereby, one molding cycle is completed. Thereafter, the above-described operation is repeatedly executed, and a predetermined number of molding cycles are repeated.

  As described above, in this embodiment, the blow molding female mold 58 is divided into two stages and opened. That is, the blow molding female mold 58 is slightly divided at the initial stage in the mold opening process of the blowing station, and then the blow molding female mold 58 is completely divided. In this case, when blow molding is completed and the mold clamping force applied to the movable platen 12 is released, the first-stage cylinder device of the split mold drive cylinder device 17 is operated, and the blow molding female die 58 is operated. The first stage mold opening is performed to slightly divide. Then, after the split part for screw 52a is divided and the grip of the mouth part of the final molded product 62 is released, and the root part 43a of the blowing guide 43 is withdrawn from the mouth part of the final molded product 62, the split part drive cylinder device The second stage cylinder device 17 is operated to perform the second stage mold opening that divides the blow molding female mold 58 into a large part, and the distance between the drive side movable part 14a and the driven side movable part 14b is at least final. It becomes larger than the outer diameter of the molded product 62, and the final molded product 62 is dropped. In this case, since the first stage operation is performed before the second stage operation is performed, the final molded product 62 is not attached to either the driving side movable part 14a or the driven side movable part 14b. Also, during the period from the first stage operation to the second stage operation, the final molded product 62 is supported by the edge B of the driving side movable part 14a and the driven side movable part 14b. Therefore, the position and posture of the final molded product 62 are stable. Therefore, when the final molded product 62 is detached from the driving side movable portion 14a and the driven side movable portion 14b, the final molded product 62 falls straight downward while maintaining a stable posture.

  Accordingly, when the blow molded female die 58 is divided and the final molded product 62 is dropped, the mold release resistance does not occur, and the final molded product 62 falls diagonally or falls in a distorted posture. Can be reliably prevented. In addition, since the final molded product 62 falls straight down while maintaining a stable posture, it collides with the driving side movable portion 14a and the driven side movable portion 14b and other members located below and is damaged. There is no end. Furthermore, the final molded products 62 do not interfere with each other and are not damaged, and the final molded product 62 does not stop between the drive-side movable portion 14a and the driven-side movable portion 14b that have been opened, so that a drop defect does not occur. Therefore, the operation of the injection blow molding machine 10 is not stopped. In the present embodiment, the case where the blow-molding female mold 58 is opened in two stages has been described, but the mold may be opened in three or more stages.

  In addition, since the final molded product 62 falls straight downward while maintaining a stable posture, the distance between the drive side movable portion 14a and the driven side movable portion 14b need not be widened. That is, in a conventional injection blow molding machine as described in the section of “Background Art”, the final molded product falls obliquely or in a distorted posture, so that the driving side movable part and the driven side movable part It is necessary to prevent the final molded product from colliding with the drive-side movable unit and the driven-side movable unit by making the interval with the part larger than the diagonal dimension of the final molded product. On the other hand, in the present embodiment, the distance between the driving side movable portion 14a and the driven side movable portion 14b is slightly larger than the outer diameter of the maximum diameter portion of the final molded product 62, for example, 20 from the outer diameter. [Mm] It only needs to be increased. Therefore, the size of the injection blow molding machine 10 can be reduced, and a large installation space is not required.

  In the present embodiment, only the case where the blow molding female die 58 is formed by the drive side movable portion 14a and the driven side movable portion 14b has been described. In addition to the movable part 14a and the driven-side movable part 14b, as shown in FIG. 12, it may be formed by a fixed bottom member 14c and a movable bottom member 14e. Further, if the distance between the drive side movable portion 14a and the driven side movable portion 14b is set larger than the diagonal dimension of the final molded product, the final molded product does not contact the movable portion.

  Further, in the present embodiment, the blow mold female mold 58 is caused to generate a slight gap β, and then the screw split molds 52a of the molded product gripping device 52 are pushed and expanded. Thus, after each of the screw split molds 52a of the molded product gripping device 52 is expanded, the blow molding female mold 58 may generate a slight gap β. At this time, since the distal end portion 43b of the base portion 43a of the blowing guide 43 is maintained in the state of entering the mouth portion of the final molded product 62, the final molded product 62 includes the driving side movable portion 14a and the driven portion. It does not adhere to the inner peripheral surface of the side movable portion 14b.

  Moreover, in this Embodiment, when performing blow molding, although the operation | movement in the case of extending | stretching the preform 61 with the extending | stretching rod 44 was demonstrated, extending | stretching of the preform 61 by the extending | stretching rod 44 can also be abbreviate | omitted.

  Furthermore, the present invention is not limited to the above-described embodiment, and various modifications can be made based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

It is a partial plane sectional view of the injection blow molding machine in an embodiment of the invention. It is a 1st figure which shows the operation | movement of mold opening of the female type | mold in the conventional injection blow molding machine. It is the 2nd figure showing operation of mold opening of a female type in the conventional injection blow molding machine. It is a fragmentary longitudinal cross-sectional view of the injection blow molding machine in embodiment of this invention. It is a principal part expansion plane sectional view of the blowing station of the injection blow molding machine in embodiment of this invention, and is a 1st figure which shows operation | movement. It is a 2nd figure which is a principal part expansion plane sectional view of the blowing station of the injection blow molding machine in embodiment of this invention, and shows operation | movement. It is a principal part expansion plane sectional view of the blowing station of the injection blow molding machine in embodiment of this invention, and is a 3rd figure which shows operation | movement. It is AA arrow sectional drawing of FIG. 7 in embodiment of this invention. It is a principal part expansion plane sectional view of the blowing station of the injection blow molding machine in embodiment of this invention, and is a 4th figure which shows operation | movement. It is a principal part expansion plane sectional view of the blowing station of the injection blow molding machine in embodiment of this invention, and is a 5th figure which shows operation | movement. It is a principal part expansion plane sectional view of the blowing station of the injection blow molding machine in embodiment of this invention, and is a 6th figure which shows operation | movement. It is a principal part expansion longitudinal cross-sectional view of the blowing station of the injection blow molding machine in embodiment of this invention, and is a figure which shows the modification of a female type | mold.

Explanation of symbols

43 Blow guide 52a Screw split mold 58 Blow molding female mold 61 Preform 62 Final molded product

Claims (5)

(A) A blow molding method for forming a final molded product by performing blow molding in a state where the mouth of an intermediate molded product at least part of which has entered the blow split mold,
(B) The blow split mold is divided into multiple stages, and the first stage of the blow split mold is supported by the mouth split mold and / or the guide for blowing in the final molded product. The blow molding method is characterized in that the final molded product is dropped from the blow split mold. The blow molding method according to claim 1, wherein after the first stage of the blow split mold is opened, the mouth split mold for gripping the mouth is opened. 2. The blow molding method according to claim 1, wherein the mouth split mold is opened while the mouth of the final molded product is supported by a blow guide, and then the first stage of the blow split mold is opened. . 4. The final mold product is separated from the inner surface of the blow split mold by the first stage opening of the blow split mold and is supported by an edge of the blow split mold. The blow molding method described in 1. The blow molding method according to any one of claims 1 to 4, wherein an interval between the blow split molds opened by the final stage of the blow split mold is larger than a diagonal dimension of the final molded product. .

Images