JP2006035674A - Injection stretch blow molding machine and injection stretch blow molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To mold a final molded product uniform in its wall thickness even if the temperature distribution or wall thickness of a preform is not uniform by stretching the preform over many stages when the injection-molded preform is stretched in a blow station, and to dispense with a heating station. <P>SOLUTION: This injection blow molding machine 10 is equipped with an injection mold support device to which a fixed mold 13 is attached, a blow mold support device to which a movable mold is attached, an injection core mold and a blowing guide and has the intermediate mold support device arranged between the injection mold support device and the blow mold support device and is constituted so as to subject an intermediate molded product molded by injection molding to blow molding to mold a final molded product. A control device for stretching the intermediate molded product over many stages is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an injection stretch blow molding machine and method.

  Conventionally, there is provided an injection stretch blow molding machine capable of performing a process of molding a test tubular preform by injection molding and a process of subjecting the preform to stretch blow molding, that is, stretch blow molding, by a single molding machine. Has been. In this case, when injection molding is performed in a state where the mold is closed at the injection station and a test tubular preform is molded, the preform is loaded into a female mold for blow molding and the mold is closed. Stretch blow molding is performed. Therefore, injection molding and stretch blow molding can be performed simultaneously at an injection station and a blow station in a single molding machine, and the throughput of the molded product is improved. In addition, since the injection molding and the stretch blow molding are performed by a single molding machine, the entire molding machine becomes compact and installation space can be saved.

In stretch blow molding, a technique for adjusting the quality of the final molded product by controlling the timing of introducing blow air has also been proposed (see, for example, Patent Document 1).
JP-A-6-254955

  However, in the conventional injection stretch blow molding machine, the temperature distribution of the preform formed by injection molding is not suitable for stretch blow molding, so the heating station is between the injection station and the blow station. The preform is heated at the heating station and then moved to the blow station to perform stretch blow molding. Therefore, it is necessary to arrange a heating station, the structure of the injection stretch blow molding machine becomes complicated, the apparatus becomes large, and the cost increases. Moreover, it takes time to heat the preform at the heating station, and the time required for the molding cycle becomes long.

  As described above, it has also been proposed to control the timing of introducing blow air, but even if the timing of introducing blow air is controlled, it is possible to eliminate uneven thickness based on the temperature distribution of the preform. I couldn't.

  The present invention solves the problems of the conventional injection stretch blow molding machine, and when the injection molded preform is stretched at the blow station, the preform is stretched in multiple stages, To provide an injection stretch blow molding machine and method that can form a final molded product having a uniform thickness even if the temperature distribution and thickness of the preform are not uniform, and does not require a heating station. Objective.

  Therefore, the injection stretch blow molding machine of the present invention includes an injection mold support device to which a fixed mold is attached, a blow mold support device to which a movable mold is attached, an injection core mold, and a blow guide. An intermediate mold support device disposed between the injection mold support device and the blow mold support device, and subjecting the intermediate molded product formed by injection molding to stretch blow molding, to obtain a final molded product Is an injection stretch blow molding machine that molds the intermediate molded product in multiple stages.

  In another injection stretch blow molding machine of the present invention, the injection mold blow molding machine further includes a mold clamping device that moves the blow mold support device, and the intermediate molded product is stretched by the operation of the mold clamping device.

  In still another injection stretch blow molding machine of the present invention, the mold clamping device can be driven by an electric motor to control the stretching speed of the intermediate molded product.

  In still another injection stretch blow molding machine of the present invention, the intermediate molded product is further stretched by a stretching rod.

  Still another injection stretch blow molding machine of the present invention includes an injection mold support device to which a fixed mold is attached, a blow mold support device to which a movable mold is attached, an injection core mold, and a blow guide. An intermediate mold support device disposed between the injection mold support device and the blow mold support device, and subjecting the intermediate molded product formed by injection molding to stretch blow molding, to obtain a final molded product Is an injection stretch blow molding machine that molds the intermediate molded product.

  The injection stretch blow molding method of the present invention is an injection stretch blow molding method by a molding machine that performs stretch blow molding on an intermediate molded product molded by injection molding to form a final molded product, wherein the intermediate molded product is Stretch in multiple stages.

  According to the present invention, an injection stretch blow molding machine includes an injection mold support device to which a fixed mold is attached, a blow mold support device to which a movable mold is attached, an injection core mold and a blow guide, An intermediate mold support device disposed between the injection mold support device and the blow mold support device, and subjecting the intermediate molded product formed by injection molding to stretch blow molding to obtain a final molded product. An injection stretch blow molding machine for molding, comprising a control device for stretching the intermediate molded product in multiple stages.

  Therefore, even if the temperature distribution and thickness of the preform are not uniform, a final molded product having a uniform thickness can be formed, and a heating station is not required.

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

  FIG. 1 is an overall side view of an injection stretch blow molding machine according to an embodiment of the present invention, FIG. 2 is a plan sectional view of an essential part of the injection stretch blow molding machine according to the embodiment of the present invention, and FIG. It is a principal part longitudinal cross-sectional view of the injection stretch blow molding machine in a form.

  1 to 3, reference numeral 10 denotes an injection stretch blow molding machine, which is slidably attached to a fixed platen 11 as an injection mold support device fixed to a support frame 18 and a guide member 18 a on the support frame 18. A movable platen 12 as a blow mold support device, and an intermediate die as an intermediate mold support device slidably attached to a guide member 18a on the support frame 18 between the fixed platen 11 and the movable platen 12. A support frame 21 is provided. The injection stretch blow molding machine 10 forms a preform 61, which will be described later, as a test tubular intermediate molded product by injection molding, and the preform 61 is described later by stretch blow molding, that is, stretch blow molding. It is a device that performs the process of forming the final molded product 62. In the injection stretch 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 at the blow station between the movable platen 12 and the intermediate mold support frame 21. Stretch blow 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 narrow-diameter open mouth, A description will be given assuming that a male screw is formed on the outer periphery.

  A fixed mold 13 as an injection mold is attached to the mold mounting surface (the left surface in FIGS. 1 to 3) 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 shows a state in which the fixed mold 13 and the injection core mold 42 are closed and closed, and FIGS. 2 and 3 show a state in which the fixed mold 13 and the injection core mold 42 are opened and the mold is opened. Shows the state.

  In FIG. 1, an injection device is provided on the back surface (right side surface in FIG. 1) of the fixed platen 11, in which only a part of the heating cylinder 16 is illustrated and other parts are not illustrated. Here, the injection device includes the heating cylinder 16, and a raw material hopper for charging raw resin such as resin pellets into the heating cylinder 16 is attached to the heating cylinder 16. Further, a screw is disposed in the heating cylinder 16 so as to be able to rotate and to advance and retreat. An injection driving device for rotating the screw in the heating cylinder 16 and moving it forward or backward is disposed behind the heating cylinder 16.

  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 backward to a predetermined position (moves in the right direction in FIG. 1). ) At this time, the raw material resin supplied from the raw material hopper is heated and melted in the heating cylinder 16, and the screw is moved backward by the pressure of the resin stored in front of the screw (left side in FIG. 1). Subsequently, in the injection process, the nozzle 16a at the tip of the heating cylinder 16 is pressed against the fixed mold 13, and the injection driving device is driven to advance the screw (move to the left in FIG. 1). As a result, the resin stored in front of the screw is injected from the tip of the nozzle 16 a and filled in a cavity formed between the fixed mold 13 and the injection core mold 42.

  Further, 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 to 3) 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. 2). 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 another set of drives. It is connected to the side movable part 14a and is moved in a direction facing the drive side movable part 14a of its own set.

  Further, 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 closes and closes the inlet of a blow molding female die 58, which will be described later, which is formed in close contact with the driving side movable portion 14a and the driven side movable portion 14b. In the state, a blow molding space having the shape of the final molded product 62 is formed. 2 and 3 show a state in which 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 to open the mold. Is shown.

  As shown in FIG. 1, a mold clamping device 80 is disposed on the back surface (left surface in FIG. 1) of the movable platen 12. The mold clamping device 80 is an electric mold clamping device driven by an electric motor, and includes a drive source 81 formed of an electric servo motor as an electric motor for driving the movable platen 12, and a support plate 82 to which the drive source 81 is attached. And a toggle mechanism 83 disposed between the support plate 82 and the movable platen 12. Further, the fixed platen 11 and the support plate 82 are connected by a plurality of, for example, four tie bars 15, and the movable platen 12 and the intermediate mold support frame 21 move forward or backward along the tie bar 15 (right side in FIG. 1). (Moving in the direction or left direction). The fixed platen 11 is fixed to the support frame 18 by a fixing member such as a bolt. The movable platen 12 and the intermediate mold support frame 21 are supported and slid mainly by the guide member 18a from below.

  In this case, the toggle mechanism 83 is operated by moving the crosshead 85 forward or backward by the drive source 81. As a result, the movable platen 12 is advanced to close the mold, and a mold clamping force obtained by multiplying the propulsive force of the drive source 81 by the toggle magnification is generated, and the mold clamping is performed by the mold clamping force. In addition, without using the toggle mechanism 83, the driving force from the driving source 81 can be directly connected to the movable platen 12 as a clamping force.

  The toggle mechanism 83 includes a toggle lever 86 that is swingably supported with respect to the cross head 85, a toggle lever 84 that is swingably supported with respect to the support plate 82, and the movable platen 12. And the toggle lever 84 and the toggle arm 87, and the toggle lever 86 and the toggle lever 84 are linked.

  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. As a result, the intermediate mold support frame 21 can be moved with respect to the fixed platen 11, and at the injection station and blowing station, mold closing, mold clamping and mold opening are performed at different timings, and injection molding and stretch blow molding are performed. It can be performed.

  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 18a, and the left and right leg portions extending in the vertical direction, and the leg portions. And a top plate portion extending in the lateral direction for 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. 2 and 3, columnar guide bars 33 extending forward and backward are attached to the front and rear sides (left and right sides in FIGS. 2 and 3) of the rotary frame 31. Yes. The number of the guide bars 33 can be arbitrarily set, but in the example shown in FIGS. 2 and 3, two guide bars 33 are attached to the left and right rotary 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. 2 and 3, the grip frame 32 is locked to the tip 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 engagement / disengagement member (not shown) attached to the movable platen 12, and is operated by a tip portion of the blow-side engagement / disengagement 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 the lower outer surface of the core mold 41, a grip release drive as a drive source for driving a grip release member for operating the molded product gripping device 52 to release the grip state. Devices 45 are each 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. Protruding.

  In the present embodiment, the movable platen 12 is advanced by the operation of the mold clamping device 80 in a state in which the extending rod 44 protrudes and the tip thereof enters the preform 61, and a screw split mold 52 a described later. However, the preform 61 is stretched so as to approach the blowing guide 43 while holding the mouth portion of the preform 61. In this case, the advance of the movable platen 12 is stopped in the middle of stretching, and the preform 61 is stretched in multiple stages. Thereafter, the final molded product 62 is formed from the preform 61 by blow molding by blowing high-pressure air. 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. 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 stretch blow molding machine 10 has a control device (not shown). The control device includes operations of the injection device, the drive source 81 of the mold clamping device 80, the intermediate drive cylinder device 22, the electric motor 34, the grip release drive device 45, the draw rod drive device 46, and the like. All operations of the blow molding machine 10 are controlled. 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 stretch blow molding machine 10 will be described in detail.

  As shown in FIGS. 2 and 3, 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 13 e. 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 portion 13a to which the tip of the nozzle 16a of the heating cylinder 16 is pressed, a sprue 13b as a resin flow path extending from the nozzle touch portion 13a, and a branch from the sprue 13b are branched. A runner 13 c serving as a resin flow path and a hot runner nozzle 13 d formed at the tip of the runner 13 c and communicating with the inside of each female mold 51 are formed. As a result, the resin injected from the tip of the nozzle 16a of the heating cylinder 16 passes through the sprue 13b, the runner 13c, and the hot runner nozzle 13d, and between each female mold portion 51 and the corresponding male mold portion 42b. The formed cavity is filled. 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 has a screw split mold 52a 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 horizontal direction (vertical direction in FIG. 2), 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 plates 52b extend in the vertical direction (perpendicular to FIG. 2) and are attached to the gripping frame 32. Each of the slide plates 52b 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 is mutually couple | bonded. 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.

  As shown in FIG. 2, the left and right rotary frames 31 that support the guide bar 33 to which the grip frame 32 is attached are supported by a support column 47 via a bearing member 47a composed of a ball bearing, a roller bearing, and the like. It is rotatably attached to the outer periphery of the. 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. 2). . 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.

  Further, when the injection stretch blow molding machine 10 is closed at the injection station and the blow station, the intermediate mold support frame 21 contacts the fixed platen 11 and the movable platen 12 contacts 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. In this case, the flange portion of the preform 61 is pressed against the outer surface of the opening portion of the blow-molding female die 58, and the portion ahead of the flange portion can enter the blow-molding female die 58. Then, when the movable platen 12 is advanced by the operation of the mold clamping device 80 with the extending rod 44 projecting and the tip thereof entering the preform 61, the extending rod 44 is relatively blow-molded female 58. The preform 61 is extended toward the back side of the blow mold female mold 58. In this case, the advance of the movable platen 12 is stopped in the middle of stretching, and the preform 61 is stretched in multiple stages. Thereafter, high pressure air is blown into the preform 61 through an air channel (not shown) to expand the preform 61 and press it against the inner surface of the blow mold female mold 58. Thereby, the bottle-shaped or bottle-shaped bottomed container which has the shape of the female mold 58 for blow molding can be shape | molded.

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

  FIG. 4 is an enlarged plan sectional view of a main part of a blowing station of an injection stretch blow molding machine according to an embodiment of the present invention, and FIG. 5 is a diagram showing the operation thereof, and FIG. 5 is an injection stretch blow molding according to the embodiment of the present invention. FIG. 6 is an enlarged plan sectional view of the main part of the blowing station of the machine, and FIG. 6 is an enlarged plan sectional view of the principal part of the blowing station of the injection stretch blow molding machine in the embodiment of the present invention. FIG. 7 is an enlarged plan sectional view of an essential part of the blowing station of the injection stretch blow molding machine in the embodiment of the present invention, and FIG. 8 is a fourth diagram illustrating the operation. FIG. FIG. 9 is an enlarged plan sectional view of a main part of the injection station of the injection stretch blow molding machine in the embodiment, and FIG. 9 shows the operation of the injection station of the injection stretch blow molding machine in the embodiment of the present invention. Is an enlarged plan sectional view FIG. 10 is an enlarged plan sectional view of an essential part of a blowing station of an injection stretch blow molding machine according to an embodiment of the present invention, and FIG. It is a figure which shows the change of the preform extended | stretched by the injection stretch blow molding machine in the form of.

  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. Then, 12 preforms 61 molded at the injection station are blow-molded, and 12 final molded products 62 as shown in FIG. 4 are molded simultaneously. In FIG. 4, the blow molding female mold 58 is opened, and the final molded product 62 falls off the driving side movable part 14 a and the driven side movable part 14 b (perpendicular to the plane of FIG. 4). Move in any direction.)

  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, as shown in FIGS. 2 and 3, the mold clamping device 80 is operated and the mold closing is started from the mold opened state at the injection station and the blowing station. . 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, before the lock between the gripping frame 32 and the guide bar 33 is released, the stretching rod driving device 46 operates, the connecting plate 46a moves forward, and the stretching rod 44 projects. As a result, as shown in FIG. 5, the distal end portion of the stretching rod 44 enters a state where the mouth portion is held by the split mold 52a for the screw. In addition, although the front-end | tip part of the said extending | stretching rod 44 may be what kind of shape, as FIG. 5 shows, it is desirable that it is a hemispherical large diameter part. The diameter of the large-diameter portion is approximately equal to the inner diameter of the substantially test tube preform 61. In addition, the split drive cylinder device 17 has already been operated, and the drive side movable portion 14a and the driven side movable portion 14b are joined and closed to form a blow molding female die 58. Yes.

  Subsequently, when the movable platen 12 further moves so as to approach the fixed platen 11 by the operation of the mold clamping device 80, the preform 61 relatively moves toward the back of the female mold 58 for blow molding, and the blow molding is performed. The inside of the female mold 58 enters the inside. When the movable platen 12 further moves so as to approach the fixed platen 11, as shown in FIG. 6, for the screw in a state where the opening of the blow molding female mold 58 holds the mouth of the preform 61. It will be in the state pressed against the split mold 52a. In this state, the flange portion of the preform 61 is pressed against the outer surface of the opening of the blow-molding female die 58, and the portion ahead of the flange portion enters the blow-molding female die 58.

  Subsequently, when the movable platen 12 further moves so as to approach the fixed platen 11 by the operation of the mold clamping device 80, the stretching rod 44 relatively moves toward the back of the preform 61, as shown in FIG. In addition, the distal end portion of the stretching rod 44 comes into contact with the bottom portion of the substantially test-form preform 61. When the movable platen 12 further moves so as to approach the fixed platen 11, the stretching rod 44 relatively moves toward the back of the blow mold female mold 58. In this case, since the mouth of the preform 61 is immovable, the bottom of the preform 61 is pulled toward the back of the blow molding female mold 58 by the tip of the stretching rod 44, and the preform 61 is stretched. Is done.

  Subsequently, as shown in FIG. 8, when the distal end of the stretching rod 44 moves a predetermined distance toward the back of the blow molding female mold 58 and stretches until the preform 61 reaches a predetermined length, the mold clamping device Since 80 temporarily stops the operation, the movable platen 12 stops. Thereby, the stretching of the preform 61 is temporarily stopped. Then, when the predetermined time has elapsed, the mold clamping device 80 resumes its operation, so that the movable platen 12 moves again so as to approach the fixed platen 11, and the stretching of the preform 61 is resumed.

  Subsequently, 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.

  Here, when the mold closing at the blowing station is completed, the driving side movable portion 14a and the driven side movable portion 14b attached to the movable platen 12 and the gripping frame 32 come into contact with each other, and the gripping frame 32 and the core mold frame 41 Are brought into contact with each other, resulting in a state as shown in FIG. In this case, the screw split mold 52a in a state of gripping the mouth of 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. The base portion 43 a of the blowing guide 43 is fitted into the mouth portion of the preform 61. Thereby, the stretching of the preform 61 by the stretching rod 44 is completed. As described above, when the stretching of the preform 61 is completed, the distal end portion of the stretching rod 44 has moved toward the back of the blow-molding female mold 58 more than when the stretching of the preform 61 is temporarily stopped. The preform 61 is stopped at the position, and the preform 61 is further stretched than when the stretching is temporarily stopped.

  In the present embodiment, as shown in FIG. 11, the thickness of the preform 61 is controlled by temporarily stopping the stretching of the preform 61 and performing it in two stages. It has become. Here, as shown in FIG. 11 (a), when the tip of the stretching rod 44 comes into contact with the bottom of the substantially test tube preform 61 and the preform 61 starts to be stretched, the preform 61 is started. It is assumed that the thickness and temperature of the reform 61 are uniform.

  Then, when the stretching rod 44 is moved relative to the preform 61 by a distance A, the preform 61 is stretched until it reaches a predetermined length, and the stretching is temporarily stopped, FIG. As shown in FIG. 4, the thickness of the portion of the preform 61, which is the bottom of the preform 61, the portion of the wedge adjacent to the portion of the preform 61, and the portion of A, which is adjacent to the mouth, is increased. The wall thickness is thin at the part of A between the part of と and the part of C. This is because when the preform 61 is stretched by the stretching rod 44, the portion of the contact with the tip of the stretching rod 44 is hardly stretched because the stretching resistance is large, whereas the bottom of the preform 61 This is because the portion of A corresponding to the body portion in the middle of the mouth portion is stretched greatly because the stretch resistance is small. In addition, since the part a is intermediate between the mouth part that is not stretched and the part i that is largely stretched, the whole part is not stretched so much and the thickness is increased. Further, since the portion of U is intermediate between the portion of D that is not stretched and the portion of B that is largely stretched, the whole portion is not stretched so much and the thickness is increased.

  Here, while the stretching is temporarily stopped, the temperature of the preform 61 decreases due to heat radiation. In this case, the thicker parts A, C, and D cool down slowly because of their large heat capacity, so the temperature rises relatively. The target temperature is lowered. As a result, at the time when the stretching of the preform 61 is resumed, the parts A, U and D are at a high temperature and the part A is at a low temperature.

  Then, the stretching is resumed, the stretching rod 44 is moved relative to the preform 61 by a distance B, the preform 61 is further stretched, and when the stretching is completed, it is shown in FIG. As described above, the thicknesses of the parts A, U and D are reduced, and the thickness is increased at the part A. This is because when the stretching is resumed and the preform 61 is stretched by the stretching rod 44, the portions a, u and e are stretched greatly because the temperature is high and the stretching resistance is small, whereas the portion a is temperature. This is because the stretching resistance is low and the stretching resistance is large, so that it does not stretch much.

  As described above, the stretching of the preform 61 is temporarily stopped in the middle, and is performed in two stages, whereby the thickness of each part of the preform 61 at the time when the stretching is completed can be controlled. Thereby, the thickness distribution of the preform 61 at the time when the stretching is completed can be made suitable for blow molding. In this case, the length for which the preform 61 is stretched in the first stretching, the length of time for which the preform 61 is temporarily stopped, and the like can be appropriately set based on the temperature distribution and the wall thickness distribution of the preform 61. In addition, the stretching of the preform 61 can be made to be in a state where the stretching speed is lowered without stopping completely in the middle. In this case, the stretching speed may be reduced to such an extent that a difference in temperature occurs between the thick part and the thin part generated in the first stretching.

  In addition, the position of the front-end | tip part of the extending | stretching rod 44 at the time of extending | stretching of the preform 61 adjusts the protrusion amount of the extending | stretching rod 44 by the drive apparatus 46 for extending | stretching rods, or makes the extending | stretching rod 44 into a different length. It can be adjusted by changing. Thereby, the extending | stretching amount of the preform 61 can be adjusted arbitrarily. Further, the speed at which the preform 61 is stretched can be controlled by controlling the driving speed of the driving source 81 to control the operating speed of the mold clamping device 80. Further, here, the case where the stretching of the preform 61 is temporarily stopped and stretched in two stages has been described, but the number of times the stretching of the preform 61 is temporarily stopped is two times or more. The stretching of the preform 61 can be divided into three or more stages.

  In the injection station, each male mold part 42 b enters each female mold 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 16a at the tip of the heating cylinder 16 is pressed against the nozzle touch portion 13a of the fixed mold 13, and the resin is injected from the tip of the nozzle 16a. 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, and high pressure air is blown into the preform 61 from the blowing guide 43, the stretching rod 44, or an air passage, an air blowing hole (not shown) formed therebetween. Thus, the preform 61 is expanded and pressed against the inner surface of the blow molding female mold 58. As a result, as shown in FIG. 10, a bottle-shaped or bottle-shaped bottomed container having the shape of the inner surface of the blow-molding female mold 58 can be formed as the final molded product 62. In this case, since the thickness distribution of the preform 61 is suitable for blow molding, a high-quality final molded product 62 having a uniform thickness at each part can be molded. In addition, when extending | stretching is complete | finished, the extending | stretching rod 44 will be returned to the original position from the protruded state.

  Thus, in the present embodiment, when the preform 61 injection-molded at the injection station is stretched at the blowing station, the preform 61 is stretched in multiple stages. Thereby, the thickness of the preform 61 at the time when the stretching is completed can be controlled. Therefore, even if the thickness and temperature distribution of the injection-molded preform 61 are inappropriate, the thickness distribution of the preform 61 at the time when the stretching is completed can be made suitable for blow molding. . Therefore, a high-quality final molded product 62 having a uniform thickness at each part can be formed by blow molding.

  That is, in stretch molding, when the preform 61 has a high temperature portion and a low temperature portion, the stretch resistance at the high temperature portion is smaller than the stretch resistance at the low temperature portion, and therefore the higher temperature portion has a higher temperature. It stretches more than the lower part. And the site | part extended greatly becomes thin, and the site | part which is not extended | stretched becomes thick. In addition, since the heat capacity is small in the thin part, the temperature is lowered by heat radiation, and the temperature is lowered in the thick part because the heat capacity is large. Therefore, by performing the stretching of the preform 61 in multiple stages, if the temperature distribution and thickness of the preform 61 are not uniform, the relatively high temperature portion is thinned in the first stage stretching, and temporarily Uniform drawing can be performed by stopping the portion or reducing the drawing speed so that the thinned portion has a relatively low temperature and the other portion is thinned in the next drawing.

  Therefore, the injection stretch blow molding machine 10 in the present embodiment does not require a heating station, and is suitable for the material and shape of the preform 61, the shape of the final molded product 62 molded by blow molding, and the like. The preform 61 having a thickness distribution can be stretched. Therefore, it is possible to obtain the injection stretch blow molding machine 10 which is small and has a simple configuration. Further, the time for heating the preform 61 is not required, and the time required for the molding cycle can be shortened. The preform 61 is made of, for example, PET (polyethylene terephthalate), but may be any material.

  Further, the injection stretch blow molding machine 10 in the present embodiment is configured to stretch the preform 61 by moving the movable platen 12 so as to approach the fixed platen 11 by the operation of the mold clamping device 80. The drive source 81 of the mold clamping device 80 is composed of an electric servo motor. That is, the injection stretch blow molding machine 10 has an electric mold clamping device, and the preform 61 is stretched by moving the stretching rod 44 relative to the preform 61 by the electric mold clamping device. Therefore, the position and speed of the stretching rod 44 relative to the preform 61 can be easily and precisely controlled. Accordingly, the stretching of the preform 61 can be precisely controlled, and the preform has an appropriate thickness distribution corresponding to the material and shape of the preform 61 and the shape of the final molded product 62 formed by blow molding. It can be stretched to be 61.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

1 is an overall side view of an injection stretch blow molding machine in an embodiment of the present invention. It is an important section plane sectional view of an injection stretch blow molding machine in an embodiment of the invention. It is a principal part longitudinal cross-sectional view of the injection stretch blow molding machine in embodiment of this invention. It is a principal part expansion plane sectional view of the blow station of the injection stretch blow molding machine in an embodiment of the invention, and is the 1st figure showing operation. It is a 2nd figure which is a principal part expansion plane sectional view of the blowing station of the injection stretch blow molding machine in embodiment of this invention, and shows operation | movement. It is a 3rd figure which is a principal part expansion plane sectional view of the blowing station of the injection stretch blow molding machine in embodiment of this invention, and shows operation | movement. It is a 4th figure which is a principal part expansion plane sectional view of the blowing station of the injection stretch 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 stretch 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 stretch blow molding machine in embodiment of this invention, and is a 6th figure which shows operation | movement. It is a principal part expansion plane sectional view of the blowing station of the injection stretch blow molding machine in embodiment of this invention, It is a 7th figure which shows operation | movement. It is a figure which shows the change of the preform extended | stretched by the injection stretch blow molding machine in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Injection stretch blow molding machine 11 Fixed platen 12 Movable platen 13 Fixed mold 14 Movable split mold 21 Intermediate mold support frame 42 Injection core mold 43 Injection guide 61 Preform 62 Final molded product 80 Clamping device

Claims (6)

(A) an injection mold support device to which a fixed mold is attached;
(B) a blow mold support device to which a movable mold is attached;
(C) comprising an injection core mold and a blowing guide, and having an intermediate mold supporting apparatus disposed between the injection mold supporting apparatus and the blowing mold supporting apparatus;
(D) An injection stretch blow molding machine that performs stretch blow molding on an intermediate molded product formed by injection molding to form a final molded product,
(E) An injection stretch blow molding machine comprising a control device for stretching the intermediate molded product in multiple stages. The injection stretch blow molding machine according to claim 1, further comprising a mold clamping device that moves the blow mold support device, and extending the intermediate molded product by an operation of the mold clamping device. 3. The injection stretch blow molding machine according to claim 2, wherein the mold clamping device is driven by an electric motor and can control a stretching speed of the intermediate molded product. The injection stretch blow molding machine according to any one of claims 1 to 3, wherein the intermediate molded product is stretched by a stretching rod. (A) an injection mold support device to which a fixed mold is attached;
(B) a blow mold support device to which a movable mold is attached;
(C) comprising an injection core mold and a blowing guide, and having an intermediate mold supporting apparatus disposed between the injection mold supporting apparatus and the blowing mold supporting apparatus;
(D) An injection stretch blow molding machine that performs stretch blow molding on an intermediate molded product formed by injection molding to form a final molded product,
(E) An injection stretch blow molding machine having an electric mold clamping device for stretching the intermediate molded product. (A) An injection stretch blow molding method by a molding machine that performs stretch blow molding to an intermediate molded product molded by injection molding to form a final molded product,
(B) An injection stretch blow molding method, wherein the intermediate molded product is stretched in multiple stages.

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