Mold equipment

Abstract

To provide a mold apparatus that can reduce the occurrence of burrs. [Solution] A mold apparatus comprising: a plurality of sets of blown split molds arranged in an opening and closing direction, each set forming a female mold for blown molding when closed and allowing the molded product to be removed when opened; and an intervening member that interposes one set of blown split molds and another set of blown split molds when the blown split molds are closed.

Description

Technical Field

[0001] The present invention relates to a mold device.

Background Art

[0002] For example, the injection blow molding machine described in Patent Document 1 includes a fixed platen fixed to a support frame, a movable platen slidably attached to a guide member on the support frame, and an intermediate mold support frame slidably attached to the guide member between the fixed platen and the movable platen. The injection blow molding machine described in Patent Document 1 is a device that performs a process of molding a preform as an intermediate molded product in a test tube shape by injection molding and a process of molding the preform into a final molded product by blow molding, that is, blow molding. In the injection blow molding machine described in Patent Document 1, injection molding is performed at an injection station between the fixed platen and the intermediate mold support frame, and blow molding is performed at a blow station between the movable platen and the intermediate mold support frame. On the mold mounting surface of the movable platen in the injection blow molding machine described in Patent Document 1, there is attached a blow mold for blow molding, which is a movable split mold forming a female mold for blow molding. The movable split mold includes a drive-side movable part and a driven-side movable part, and the drive-side movable part and the driven-side movable part are moved in the lateral direction by a split mold drive cylinder device as a split mold drive device. In this case, the drive-side movable part is connected to the piston rod of the split mold drive cylinder device and is directly moved by the split mold drive cylinder device, and the driven-side movable part is connected to another set of drive-side movable parts and is moved in a direction facing the drive-side movable part of its own set. The split mold drive cylinder device is, for example, a pneumatic cylinder device that operates by compressed air.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0004] If the closing force of the split mold is weak, a large gap may form between the split molds when air is blown into the closed split mold for blow molding. For example, if the device that opens and closes the split mold is a pneumatic cylinder device, the closing force of the split mold will be weaker compared to, for example, a device that opens and closes the split mold using a ball screw. If the gap between the split molds is large enough for resin to overflow, burrs may form on the final molded product. The present invention aims to provide a mold apparatus that can reduce the occurrence of burrs. [Means for solving the problem]

[0005] The present invention, completed with this objective in mind, is a mold apparatus comprising: a plurality of sets of blown split molds arranged in an opening and closing direction, each set of which forms a female blown mold for blown molding when closed and allows the molded product to be removed when opened; and an intervening member which is interposed between one set of blown split molds and another set of blown split molds when the blown split molds are closed. Here, the blowing splitter may open when the intervening member is retracted in a direction intersecting the opening and closing direction. Furthermore, when the blowing mold is closed, the gap between the blowing mold and the intervening member may be 0.03 mm or more and less than 0.09 mm. Furthermore, when the blowing mold is closed, the gap between the blowing mold and the intervening member may be 0.03 mm or more and 0.05 mm or less. Furthermore, the blowing splitter may be opened and closed by a pneumatic cylinder device. Furthermore, there may be two sets of the blowing molds, and one intervening member may be interposed between the two sets of blowing molds. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a mold apparatus that can reduce the occurrence of burrs. [Brief explanation of the drawing]

[0007] [Figure 1] This is a view in the vertical direction of an example of a cross-section of an injection molding machine according to the first embodiment. [Figure 2] This is a view in a second direction of an example of a cross-section of an injection molding machine according to the first embodiment. [Figure 3] (a) is a diagram showing an example of a cross-section of the final molded product before molding. (b) is a diagram showing an example of a cross-section of the final molded product after molding. [Figure 4] This is an example of a view of an injection molding machine as seen in the direction of section IV in Figure 2. [Figure 5] This figure shows an example of a cross-section of section VV in Figure 4. [Figure 6] This figure shows an example of a cross-section of section VV in Figure 4. [Figure 7] This figure shows the relationship between the size of the gap D and the appearance defects, wear dust generation, and burr defects of the final molded product. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described in detail below with reference to the attached drawings. <First Embodiment> Figure 1 is a view in the vertical direction of an example of a cross-section of the injection blow molding machine 1 according to the first embodiment. Figure 2 is a view of an example of a cross-section of the injection blow molding machine 1 according to the first embodiment, as seen in the second direction. Figure 3(a) shows an example of a cross-section of the final molded product 600 before molding. Figure 3(b) shows an example of a cross-section of the final molded product 600 after molding. Figures 1 and 2 show the state in which the fixed mold 10 and the injection core mold 51 are opened. Also, Figures 1, 2 and 3(b) show the state in which the drive-side movable part 22a and the driven-side movable part 22b of the movable injection split mold 22 are opened, and the movable injection split mold 22 and the injection guide 52 are opened, resulting in a mold-open state.

[0009] The injection and blow molding machine 1 is a device that performs injection molding (in other words, injection molding) and blow molding (in other words, blow molding). The injection and blow molding machine 1 forms an intermediate molded product, such as a test tube-shaped preform 610, by injection molding, and then forms a final molded product 600, such as a container, by blow molding, which expands the inside of the preform 610 by blowing high-pressure air into it.

[0010] The injection molding machine 1 comprises a fixed mold 10, a movable mold 20 that is movable relative to the fixed mold 10, and an intermediate mold 30 positioned between the fixed mold 10 and the movable mold 20. The injection molding machine 1 performs injection molding at the injection station between the fixed mold 10 and the intermediate mold 30 by closing the molds of the fixed mold 10 and the intermediate mold 30. The injection molding machine 1 also performs blow molding at the blow station between the intermediate mold 30 and the movable mold 20 by closing the molds of the intermediate mold 30 and the movable mold 20. Hereafter, the direction of movement of the movable mold 20 relative to the fixed mold 10 (in other words, the left and right directions in Figures 1 and 2) may be referred to as the "first direction." In the first direction, the side on which the fixed mold 10 is positioned may be referred to as the "first side," and the side on which the movable mold 20 is positioned may be referred to as the "second side." The injection molding machine 1 is positioned such that the up and down direction in Figure 2 is the top and bottom direction. In the following, the vertical direction in Figure 2 may be simply referred to as the "vertical direction." Furthermore, the direction perpendicular to the first direction and the vertical direction (in other words, the vertical direction in Figure 1) may be referred to as the "second direction."

[0011] The injection blow molding machine 1 is fixed to a frame 500 fixed to the floor, and includes a fixed platen 11 that holds the fixed mold 10, and a movable platen 21 that is slidably attached to a guide member 510 on the frame 500 and holds the movable mold 20. Further, the injection blow molding machine 1 includes an intermediate mold support frame 31 that supports an intermediate mold 30 and is slidably attached to the guide member 510 between the fixed platen 11 and the movable platen 21.

[0012] Further, the injection blow molding machine 1 includes an injection device (not shown) that injects resin into the cavity formed between the fixed mold 10 and the intermediate mold 30 on the side opposite to the fixed mold 10 with respect to the fixed platen 11. Further, the injection blow molding machine 1 includes a mold clamping device (not shown) on the side opposite to the movable mold 20 with respect to the movable platen 21. The mold clamping device has a mold clamping cylinder device (not shown) for driving the movable platen 21 and a support plate (not shown) to which the mold clamping cylinder device is attached. The support plate and the fixed platen 11 are connected by a plurality (for example, four) of tie bars 520. The fixed platen 11 is fixed to the frame 500 by bolts or the like. The movable platen 21 and the intermediate mold support frame 31 are mainly supported from below by the guide member 510 and move in the first direction along the tie bars 520.

[0013] Further, the injection blow molding machine 1 includes a cavity plate 13 having a plurality of female mold parts 12. In the present embodiment, a total of 12 female mold parts 12 are provided so as to form two rows of six columns in the vertical direction, and a cavity plate 13 having the 12 female mold parts 12 is attached to the fixed mold 10.

[0014] The movable mold 20 has a movable blow split mold 22, a first bottom mold 23, a second bottom mold 24, and a suction device 25 that sucks the final molded product 600. The movable injection split mold 22 has a driving-side movable part 22a and a driven-side movable part 22b that are arranged opposite to each other. The driving-side movable part 22a and the driven-side movable part 22b are moved in the second direction by a split mold driving cylinder device 26 to come into contact with and separate from each other. And when the driving-side movable part 22a and the driven-side movable part 22b come into contact with each other, a female mold 27 for injection molding is formed. In the present embodiment, six female molds 27 for injection molding arranged in the vertical direction in a set of the driving-side movable part 22a and the driven-side movable part 22b are formed, and two sets of the driving-side movable parts 22a and the driven-side movable parts 22b are arranged side by side in the second direction. The driving-side movable part 22a is connected to the piston rod 26a of the split mold driving cylinder device 26 and is directly moved by the split mold driving cylinder device 26. The driven-side movable part 22b is connected to the driving-side movable part 22a of another set and is moved in the second direction so as to come into contact with and separate from the driving-side movable part 22a of its own set. The split mold driving cylinder device 26 can be exemplified as, for example, a pneumatic cylinder device. When the movable mold 20 according to the present embodiment forms the female mold 27 for injection molding by the driving-side movable part 22a and the driven-side movable part 22b coming into contact with each other and performs injection molding, it has an intervening member 28 (see FIGS. 4, 5, and 6) intervening between one set of the driven-side movable parts 22b and another set of the driven-side movable parts 22b. The intervening member 28 will be described in detail later.

[0015] The first bottom mold 23 is attached to the movable platen 21. A through hole 23a penetrating in the first direction is formed in the first bottom mold 23. The through hole 23a is arranged on the extension line of the center line of the final molded product 600 in a state where the driving-side movable part 22a and the driven-side movable part 22b are mold-closed, and forms a space where the second bottom mold 24 can be arranged. Around the through hole 23a in the first bottom mold 23, a recess 23b recessed from the contact surface with the movable injection split mold 22 is formed.

[0016] The second bottom mold 24 is a cylindrical member and is positioned in the through hole 23a of the first bottom mold 23. The second bottom mold 24 is positioned to protrude slightly from the recess 23b of the first bottom mold 23 toward the first side in the first direction. The diameter of the second bottom mold 24 is slightly smaller than the diameter of the through hole 23a of the first bottom mold 23. Therefore, when the second bottom mold 24 is positioned in the through hole 23a, a gap is formed between the first bottom mold 23 and the second bottom mold 24.

[0017] The suction device 25 consists of a vacuum pump and the like, and sucks up the final molded product 600. Specifically, the suction device 25 sucks up the final molded product 600 using the gap formed between the first bottom mold 23 and the second bottom mold 24 as an air passage during suction.

[0018] The intermediate mold 30 includes a rotating frame 35 that is rotatably attached to the intermediate mold support frame 31, and a core mold frame 50 that is not rotatably attached to the intermediate mold support frame 31. Here, the intermediate support frame 31 comprises rectangular parallelepiped-shaped legs 32, which are positioned at both ends in the second direction and are shaped such that the vertical direction is the longitudinal direction and the first direction is the short direction; a top plate 33u connecting the upper parts of both legs 32; and a bottom part 33b connecting the lower parts of both legs 32. A cylindrical support column 34 is fixed to the vertical center of each leg 32, and is attached so as to penetrate the leg 32 in the second direction. Furthermore, through holes (not shown) in the first direction for passing tie bars 520 are formed in the upper and lower parts of each leg 32.

[0019] The rotating frame 35 is attached to the outer circumference of the support column 34 via bearing members 36 such as ball bearings, and is rotatable relative to the intermediate support frame 31 with the centerline of the support column 34 as the center of rotation. In this embodiment, an annular driven gear 37 is attached to the side surface of the rotating frame 35, and a drive gear 38b attached to the rotating shaft 38a of the electric motor 38 meshes with the driven gear 37. As a result, the rotating frame 35 rotates around the support column 34 when the electric motor 38 is operated.

[0020] The intermediate mold 30 has a plurality of guide bars 39 attached to the rotating frame 35 so as to extend in a first direction, and a gripping frame 40 that is slidably attached to the guide bars 39 in the first direction. In this embodiment, in the open state shown in Figures 1 and 2, the intermediate mold 30 has one guide bar 39 at the first end of the rotating frame 35, and one at the upper and lower ends of each end in the second direction. In addition, the rotating frame 35 has one guide bar 39 at the second end, and one at the upper and lower ends of each end in the second direction. In other words, the intermediate mold 30 according to this embodiment has a total of eight guide bars 39. However, the intermediate mold 30 may also have four guide bars at the upper and lower ends of each end in the second direction, extending on both the fixed mold 10 side and the movable mold 20 side.

[0021] In the state shown in Figures 1 and 2, one gripping frame 40 is provided at each end of the rotating frame 35 in the first direction. The gripping frames 40 are slidably mounted on four guide bars 39, which are located on the same side with respect to the centerline of the support column 34. The gripping frame 40 has a gripping device 41 for forming and gripping the mouth portion 620 of the final molded product 600. The gripping device 41 includes a screw split mold 42 for forming and gripping the mouth portion 620, a slide plate 43 to which the screw split mold 42 is attached, and a gripping release member 44 for releasing the grip of the mouth portion 620. The gripping release member 44 is driven by a gripping release drive device (not shown). The screw split mold 42 forms the mouth portion 620 in a closed state during injection molding and grips the mouth portion 620 in a closed state during blow molding. The screw split mold 42 also releases the mouth portion 620 by opening the mold after the completion of blow molding.

[0022] More specifically, the screw mold 42 is configured to be separable in a second direction, with each half of the screw mold 42 attached to the half of the slide plate 43. The half of the slide plate 43 is also attached to the gripping frame 40 so as to be slidable in the second direction. The gripping release member 44 is configured to be separable in a second direction, with each half of the gripping release member 44 attached to the half of the slide plate 43. When the gripping release member 44 is pushed open in the second direction, the half of each slide plate 43 and the half of each screw mold 42 are also pushed open and separated in the second direction. This releases the grip of the mouth 620 of the final molded product 600 after the blow molding is completed at the blow station. In this embodiment, the screw split mold 42 is provided at positions corresponding to the female mold portion 12 attached to the fixed mold 10 and the female mold 27 for blow molding of the movable blow split mold 22. In other words, in the state shown in Figures 1 and 2, the screw split mold 42 forms two rows of six pieces arranged vertically.

[0023] The core formwork 50 is fixed to the support column 34, thereby being non-rotatably attached to the intermediate support frame 31. An injection core mold 51 is attached to the side of the core mold 50 facing the fixed platen 11, and a blowing guide 52 is attached to the side of the core mold 50 facing the movable platen 21. The injection core mold 51 has a base portion 51a and a male mold portion 51b, and in the closed state, it forms a cavity with the shape of the preform 610 between itself and the female mold portion 12. The blowing guide 52 has a base portion 52a and, when in a closed state, is in close contact with the entrance of the female mold 27 for blow molding, which is formed by the close contact of the drive-side movable portion 22a and the driven-side movable portion 22b, and forms a space for blow molding that has the shape of the final molded product 600.

[0024] The intermediate mold 30 also includes a stretch rod 53 that can protrude from the base portion 52a of the blowing guide 52, a connecting plate 54 to which the base portions of the multiple stretch rods 53 are attached, and a stretch rod drive device 55 for protruding the stretch rods 53. The stretch rod drive device 55 can be exemplified as, for example, a pneumatic cylinder device. The stretch rod drive device 55 can be exemplified as being attached to the upper and lower outer surfaces of the core mold 50. The connecting plate 54 is connected to the piston rod of the stretch rod drive device 55. When the stretch rod drive device 55 is operated, the connecting plate 54 connected to the piston rod moves, and the stretch rod 53 protrudes into the preform 610. In this embodiment, the final molded product 600 is formed from the preform 610 by stretch-blow molding, in which the stretch rod 53 is made to protrude into the preform 610, and high-pressure air is blown into the preform 610 while stretching it.

[0025] Furthermore, the injection molding machine 1 includes an intermediate mold drive cylinder device 15 that moves the intermediate mold support frame 31 in a first direction relative to the fixed platen 11, and a connecting rod 16 connected to the piston rod of the intermediate mold drive cylinder device 15. The intermediate mold drive cylinder device 15 is fixed to the fixed platen 11, and the connecting rod 16 is attached to the intermediate mold support frame 31. By operating the intermediate mold drive cylinder device 15, the intermediate mold support frame 31 can be moved relative to the fixed platen 11. As a result, the injection molding machine 1 can perform injection molding and blow molding by closing, clamping, and opening the mold at separate timings in the injection station and the blowing station.

[0026] Furthermore, the injection molding machine 1 has a control device 70 that controls the injection molding machine 1. The control device 70 has a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) (not shown) which is a memory area for storing programs, and a RAM (Random Access Memory) (not shown) which is a program execution area. The control device 70 realizes various functions by having the CPU execute programs stored in the ROM or a storage device such as an HDD (Hard Disk Drive) or semiconductor memory. The control device 70 controls the operation of the injection device (not shown), the clamping device (not shown), the split mold drive cylinder device 26, the intervening member drive cylinder device (not shown) which will be described later, the electric motor 38, the grip release drive device (not shown), the stretch rod drive device 55, etc. The operation of the injection molding machine 1, which is performed based on the control by the control device 70, will be described below.

[0027] (operation) In this embodiment, the injection blow molding machine 1, in one molding cycle, forms 12 preforms 610 equal to the number of female molds 12 by injection molding at the injection station. In addition, at the blow station, the injection blow molding machine 1 uses the same number of preforms 610 formed at the injection station in the previous molding cycle to perform blow molding and form 12 final molded products 600.

[0028] First, as shown in Figures 1 and 2, the mold opens at the injection station and blowing station, and a mold clamping device (not shown) activates to begin closing the mold. This causes the movable platen 21 to move from the open state to the closed state, that is, closer to the fixed platen 11. While the movable platen 21 is moving from the open state to the closed state, the intermediate mold drive cylinder device 15 activates, causing the intermediate mold support frame 31 to move from the open state to the closed state, that is, closer to the fixed platen 11. Before the movable platen 21 moves from the open state to the closed state, the split mold drive cylinder device 26 is activated, causing the drive-side movable part 22a and the driven-side movable part 22b to move in the second direction and close, forming the female mold 27 for blow molding.

[0029] Then, when the movable platen 21 is in the closed position, the mold closing is completed at the injection station and the blowing station. In this case, the gripping frame 40 at the injection station and the blowing station is in contact with the core mold 50.

[0030] In this case, at the injection station, each male mold portion 51b is inserted into each female mold portion 12 attached to the fixed mold 10. A cavity is formed between the inner surface of the female mold portion 12 and the screw split mold 42 and the outer surface of the male mold portion 51b. The resin injected by the injection device is then filled into the cavity. Even after the resin filling is complete, the mold remains closed to cool the resin inside the cavity.

[0031] Furthermore, in the blowing station, as shown in Figure 3(a), the screw split mold 42, which is gripping the mouth 620 of the preform 610, is pressed against the opening of the blow-molding female mold 27 formed by the drive-side movable part 22a and the driven-side movable part 22b. As a result, the flange of the preform 610 is pressed against the outer surface of the opening of the blow-molding female mold 27, and the part beyond the flange enters the inside of the blow-molding female mold 27. Also, the tip 52b of the base 52a of the blowing guide 52 enters the mouth 620 of the preform 610. Then, the stretch rod drive device 55 is activated, and the stretch rod 53 protrudes toward the back of the blow-molding female mold 27, and at the same time, high-pressure air is blown into the inside of the preform 610, causing the preform 610 to expand and press against the inner surface of the blow-molding female mold 27. As a result, as shown in Figure 3(b), a bottle-shaped or bottle-shaped bottomed container having the shape of the inner surface of the female mold 27 for blow molding is formed as the final molded product 600. When the stretching is complete, the stretching rod 53 is returned to its original position from its protruding state. Then, when the blow molding is complete, the clamping force applied to the movable platen 21 by the mold clamping device is released.

[0032] Subsequently, while maintaining the positional relationship between the drive-side movable part 22a and the driven-side movable part 22b and the gripping device 41, the movable platen 21 moves away from the core mold 50. Then, when a predetermined gap is formed between the screw split mold 42 and the blowing guide 52, the drive-side movable part 22a and the driven-side movable part 22b move in a second direction. The screw split mold 42 is also pushed open in the second direction, opening the mouth 620. Then, when the distance between the drive-side movable part 22a and the driven-side movable part 22b becomes at least greater than the outer diameter of the final molded product 600, the final molded product 600 falls downward from between the drive-side movable part 22a and the driven-side movable part 22b. The final molded product 600 is discharged below the injection blowing molding machine 1 and stored in a storage device (not shown).

[0033] Subsequently, the intermediate mold drive cylinder device 15 operates, causing the intermediate mold support frame 31 to move from the mold closed state to the mold open state, that is, away from the fixed platen 11. As the core mold frame 50 moves along with the intermediate mold support frame 31, the male mold portion 51b is pulled out from the female mold portion 12 attached to the fixed mold 10. Subsequently, as the intermediate mold support frame 31 moves further away from the fixed platen 11, the gripping frame 40 also moves along with it, and the screw split mold 42 is pulled out from the female mold portion 12. In this case, the split portion of the screw split mold 42 is biased toward the center by the biasing member and is connected to each other, so it grips the mouth portion 620 of the preform 610.

[0034] As a result, the gripping frame 40 in the injection station reaches a position away from the fixed mold 10 with the screw split mold 42 gripping all 12 preforms 610. Next, the electric motor 38 is activated, causing the rotating frame 35 to rotate around the centerline of the support column 34. As a result, the gripping frame 40 in which the screw mold 42 grips the preform 610 moves from the injection station to the blowing station, and the other gripping frame 40 moves from the blowing station to the injection station.

[0035] Then, when the rotation of the rotating frame 35 is complete, the mold opens at the injection station and the blowing station. This completes one molding cycle. Thereafter, the above operation is repeated, and a predetermined number of molding cycles are repeated.

[0036] (Regarding the intervening member 28 of the movable mold 20) Figure 4 is an example of a view of the injection molding machine 1 as seen in the direction of section IV in Figure 2. Figures 5 and 6 show an example of a cross-section of section VV in Figure 4. Figures 4 and 5 show an example of the intervening state described later, and Figure 6 shows an example of the retracted state described later. In the movable blow-molding split mold 22 of the movable mold 20 according to this embodiment, the drive-side movable part 22a and the driven-side movable part 22b are moved in a second direction by the split mold drive cylinder device 26 (see Figure 1), causing them to come into contact or separate. When the drive-side movable part 22a and the driven-side movable part 22b come into contact, in other words, when the drive-side movable part 22a and the driven-side movable part 22b close together, a blow-molding female mold 27 for blow molding is formed. When the drive-side movable part 22a and the driven-side movable part 22b separate, in other words, when the drive-side movable part 22a and the driven-side movable part 22b open together, the final molded product 600 can fall downward from between the drive-side movable part 22a and the driven-side movable part 22b.

[0037] As shown in Figures 4 and 5, the external shape of the movable blowing splitter 22 is a rectangular parallelepiped, and when viewed in the first direction, the shape of the movable blowing splitter 22 is a rectangle with the vertical direction being the longitudinal direction and the second direction being the short direction. The two end faces of the movable blowing splitter 22 in the second direction are each perpendicular to the second direction.

[0038] As shown in Figures 4 and 5, when the movable blowing splitter 22 is closed, the intervening member 28 is interposed between the driven movable part 22b of one set of the two sets of movable blowing splitters 22 and the driven movable part 22b of the other set of movable blowing splitters 22. Also, as shown in Figure 6, when the movable blowing splitter 22 is open, the intervening member 28 retracts from between the driven movable part 22b of one set of the two sets of movable blowing splitters 22 and the driven movable part 22b of the other set of movable blowing splitters 22. By moving in the first direction, the intervening member 28 transitions between a state in which it is interposed between the two driven movable parts 22b (hereinafter sometimes referred to as the "intervening state") and a state in which it has retracted from between the two driven movable parts 22b (hereinafter sometimes referred to as the "retracted state").

[0039] The intervening member 28 is connected to a piston rod (not shown) of an intervening member drive cylinder device (not shown), and is moved in a first direction by the intervening member drive cylinder device. The intervening member drive cylinder device is attached to the first bottom mold 23 or the movable platen 21, and the piston rod is connected to the intervening member 28 through a through hole formed in the first bottom mold 23. Furthermore, when the intervening member 28 is in the retracted state, it is positioned in a through hole or recess formed in the first bottom mold 23. The intervening member drive cylinder device may be a pneumatic cylinder device, a hydraulic cylinder device, or a device using a ball screw or toggle mechanism.

[0040] The intervening member 28 has surfaces perpendicular to the second direction at each end in the second direction. Hereinafter, in the intervening state, the surface of the driven movable part 22b of the movable blowing split mold 22 that faces the intervening member 28 may be referred to as the "first surface 201," and the surface of the intervening member 28 that faces the first surface 201 may be referred to as the "second surface 202." For example, the external shape of the intervening member 28 is a rectangular parallelepiped, and as shown in Figure 4, the shape of the intervening member 28 when viewed in the first direction can be exemplified as a rectangle with the vertical direction being the longitudinal direction and the second direction being the short direction. However, although not shown, the intervening member 28 may have holes or recesses extending in the first direction to allow for the placement of rails that support the movement of the intervening member 28 in the first direction. For example, the holes or recesses extending in the first direction can be exemplified as being formed in the center in the vertical direction. The second surface 202 may consist of a single continuous surface in the vertical direction, or it may consist of multiple surfaces intermittently arranged in the vertical direction. If the second surface 202 consists of multiple surfaces, it is desirable that it has at least two surfaces: one at the top and one at the bottom.

[0041] In this embodiment, the gap between the first surface 201 and the second surface 202 in the interposed state is as follows. That is, the gap D between the first surface 201 and the second surface 202 is set to be a value of 0.03 (mm) or more and less than 0.09 (mm). This will be explained below.

[0042] In the movable blow-molding split mold 22 of the movable mold 20 according to this embodiment, the drive-side movable part 22a and the driven-side movable part 22b are kept in a closed state (in other words, tightly sealed state) by a split mold drive cylinder device 26 (see Figure 1), which is a pneumatic cylinder device. Since pneumatic cylinder devices have less force than hydraulic cylinder devices and devices using ball screws or toggle mechanisms, the force that maintains the closed state of the movable blow-molding split mold 22 is also weak. Therefore, when high-pressure air is blown into the interior of the preform 610 during blow molding via an air passage or air ejection hole (not shown) formed between the stretching rod 53 and the gripping device 41, a gap is created between the drive-side movable part 22a and the driven-side movable part 22b. Hereinafter, the gap between the drive-side movable part 22a and the driven-side movable part 22b may be referred to as "gap M". If gap M is large, burrs will be generated on the final molded product 600. Therefore, if the split mold drive cylinder device 26 is a pneumatic cylinder device, there is a high risk that the gap M will become large enough to generate burrs on the final molded product 600. In this embodiment, in order to prevent the gap M from becoming large enough to generate burrs on the final molded product 600, an intervening member 28 is interposed between the two sets of movable blown split molds 22 during blow molding to suppress the opening of the movable blown split molds 22.

[0043] On the other hand, in blow molding, if the air that was present in the blow molding female mold 27 before high-pressure air was blown into the preform 610 is not discharged to the outside of the blow molding female mold 27, it may cause defects in the appearance of the final molded product 600. Therefore, in this embodiment, in order to prevent defects in the appearance of the final molded product 600, a gap M is used to release the air to the outside of the blow molding female mold 27 when high-pressure air is blown in.

[0044] From the viewpoint of preventing the gap M from becoming so large as to generate burrs on the final molded product 600, it is preferable for the gap D to be small in order to reduce the gap M. This is to make it difficult to open the drive-side movable part 22a and the driven-side movable part 22b. On the other hand, from the viewpoint of using the gap M to release air in order to prevent surface defects in the final molded product 600, it is preferable for the gap D to be large in order to increase the gap M. This is to make it easier to open the drive-side movable part 22a and the driven-side movable part 22b.

[0045] Furthermore, if the gap D is small, when the intervening member 28 transitions from the retracted state to the intervening state, the second surface 202 of the intervening member 28 may come into contact with the first surface 201 of the movable blowing mold 22, potentially generating wear particles. In this embodiment, since the final molded product 600 falls downward by its own weight from between the driving-side movable part 22a and the driven-side movable part 22b, there is a risk that wear particles will adhere to the final molded product 600 located below. Therefore, a larger gap D is preferable to suppress the generation of wear particles.

[0046] Figure 7 shows the relationship between the size of the gap D and the appearance defects, wear dust generation, and burr defects of the final molded product 600. The inventors investigated how the appearance defects, wear particle generation, and burr defects of the final molded product 600 change depending on the size of the gap D. The final molded product 600 is a 110 ml beverage bottle container molded using PET (Polyethylene Terephthalate). It is believed that the same changes as shown in Figure 7 will occur even if the final molded product 600 is a bottle container between 65 ml and 200 ml.

[0047] As shown in Figure 7, when the gap D was 0.005 mm and 0.01 mm, the final molded product 600 had appearance defects. On the other hand, when the gap D was 0.03 mm or more, the final molded product 600 did not have appearance defects. Furthermore, when the gap D was 0.02 mm, some final molded products 600 did not have appearance defects, while others did. From the above, from the viewpoint of using the gap M to release air in order to prevent appearance defects in the final molded product 600, it is preferable that the gap D is 0.03 mm or more. This is because when the gap D is less than 0.03 mm, it is unlikely that the gap M will be large enough to release air.

[0048] As shown in Figure 7, wear particles were generated when the gap D was 0.005 mm and 0.01 mm. On the other hand, no wear particles were generated when the gap D was 0.03 mm or larger. Furthermore, when the gap D was 0.02 mm, there were cases where no wear particles were generated, and cases where they were generated. From the above, from the viewpoint of preventing the generation of wear particles, it is preferable that the gap D be 0.03 mm or larger. This is because it is thought that wear particles may be generated when the gap D is less than 0.03 mm.

[0049] As shown in Figure 7, burrs were generated when the gap D was 0.09 mm or larger. On the other hand, no burrs were generated when the gap D was 0.05 mm or smaller. Furthermore, when the gap D was between 0.06 mm and less than 0.09 mm, some final molded products 600 did not have burrs, while others did. However, when the gap D was between 0.06 mm and less than 0.09 mm, the size of the burrs generated on the final molded product 600 was smaller than the size of the burrs generated on the final molded product 600 when the gap D was 0.09 mm or larger. Therefore, from the viewpoint of preventing burr generation, it is preferable for the gap D to be less than 0.09 mm, and more preferable for it to be less than 0.06 mm.

[0050] As described above, the movable mold 20 comprises multiple sets of movable blowing split molds 22, each set of which forms a female blowing mold 27 for blowing when closed, arranged in a second direction (an example of an opening and closing direction). The movable blowing split molds 22 can be opened to remove the final molded product 600. The movable mold 20 also comprises an intervening member 28 which is interposed between one set of movable blowing split molds 22 and the other sets of movable blowing split molds 22 when the movable blowing split molds 22 are closed.

[0051] In the movable mold 20 configured as described above, the intervening member 28 suppresses the movement of the movable injection mold 22, so even if high-pressure air is blown into the female mold 27 for injection molding during injection molding, a gap M is unlikely to form between the driving movable part 22a and the driven movable part 22b. Therefore, the generation of burrs on the final molded product 600 can be suppressed. Even if the movable injection mold 22 is opened and closed by a pneumatic cylinder device, the intervening member 28 prevents the movable injection mold 22 from opening.

[0052] The movable injection mold 22 opens when the intervening member 28 is retracted in a direction that intersects the second direction (for example, the first direction). This makes it possible to open the movable injection mold 22 when the intervening member 28 is retracted when dropping the final molded product 600.

[0053] Furthermore, when the movable injection mold 22 is closed, the gap D between the movable injection mold 22 and the intervening member 28 is preferably 0.03 mm or more and less than 0.09 mm. By having a gap D of 0.03 mm or more and less than 0.09 mm, it is possible to suppress the generation of burrs while suppressing defects in the appearance of the final molded product 600 and the generation of wear particles. Furthermore, it is more preferable that the gap D is between 0.03 mm and 0.05 mm. This allows for a high degree of reliability in suppressing the generation of burrs.

[0054] Furthermore, in the movable mold 20 according to this embodiment, there are two sets of movable injection molds 22, and one intervening member 28 is interposed between the two sets of movable injection molds 22. In other words, one intervening member 28 can prevent the two sets of movable injection molds 22 from opening. If there are four or more even sets of movable injection molds 22, similarly, one intervening member 28 can be placed between two sets of movable injection molds 22, and it is not necessary to place one movable injection mold 22 for each set. [Explanation of symbols]

[0055] 1…Injection blow molding machine, 10…Fixed mold, 11…Fixed platen, 20…Movable mold (example of mold device), 21…Movable platen, 22…Movable blow-in split mold, 22a…Driver-side movable part, 22b…Driven-side movable part, 27…Female mold for blow molding, 28…Intervening member, 600…Final molded product

Claims

1. Multiple sets of blown molds are arranged in an open / close direction, with each set forming a female mold for blown molding when closed and allowing the molded product to be removed when opened. When the blowing mold is closed, an intervening member is interposed between one set of blowing molds and another set of blowing molds among the multiple sets of blowing molds, A mold apparatus equipped with the following features.

2. The blowing splitter opens when the intervening member is retracted in a direction intersecting the opening and closing direction. The mold apparatus according to claim 1.

3. When the blowing mold is closed, the gap between the blowing mold and the intervening member is 0.03 mm or more and less than 0.09 mm. The mold apparatus according to claim 1.

4. When the blowing mold is closed, the gap between the blowing mold and the intervening member is 0.03 mm or more and 0.05 mm or less. The mold apparatus according to claim 3.

5. The aforementioned blowing splitter is opened and closed by a pneumatic cylinder device. The mold apparatus according to claim 1.

6. There are two sets of the aforementioned blowing molds. The intervening member is interposed between the two sets of blowing molds. The mold apparatus according to claim 1.

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