Stretching rod sliding mechanism, intermediate die and die device
By designing a stretch rod sliding mechanism with preset gaps during injection molding and air blow molding, the problems of unevenness and offset of molded products caused by unstable tension rod movement are solved, and a more stable forming process and product quality are achieved.
Patent Information
- Application Number
- CN202411391308.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-12-07
- Filing Date
- 2024-10-08
- Publication Date
- 2025-06-10
AI Technical Summary
During the injection molding and air blow molding process, the movement of the stretching rod is unstable, resulting in uneven wall thickness of the molded product and channel offset.
A stretch rod sliding mechanism is designed to ensure stable movement of the stretch rod and the stretching plate by forming a preset first gap between the stretch rod and the blow molding core, a preset second gap between the guide rod and the stretching plate, and a third gap of the gap is formed at the joint portion between the stretching rod and the stretching plate.
Through this design, the movement of the stretching rod can be made more stable, avoid unevenness and offset problems of the molded product, and reduce friction between the blow-molded core and the stretching rod, preventing the grinding and mold biting.
Smart Images
Figure CN120116464A_ABST
Abstract
Description
[0001] This application claims priority based on Japanese Patent Application No. 2023-206699 filed on December 7, 2023. The entire content of this Japanese application is incorporated herein by reference. Technical Field
[0002] The present invention relates to a stretching rod sliding mechanism, an intermediate mold, and a mold device. Background Art
[0003] In an injection blow molding method, which is a molding method that performs injection molding and blow molding in two stages, a preform as an intermediate molded product is molded by injection molding, and air is blown into the inside of the preform and expanded by blow molding to mold a product such as a container. In the blow molding of injection blow molding, a stretching rod having one end joined to a stretching plate and the other end passing through a through hole of a blow mold core slides in the through hole of the blow mold core as the stretching plate moves, and the front end portion enters the preform and air is blown in (for example, Patent Document 1).
[0004] Patent Document 1: Japanese Patent No. 4425750
[0005] The through hole of the blow mold core guides the stretching rod that moves axially. However, if a certain force is applied to the stretching plate and the movement becomes unstable, the movement of the stretching rod joined to the stretching plate also becomes unstable, sometimes causing "eccentricity" such as unevenness in the wall thickness of the molded product or channel deviation. Moreover, sometimes powder is generated due to friction between the blow mold core and the stretching rod, or die biting of the mold occurs. Therefore, it is preferable that the movement of the stretching plate and the movement of the stretching rod are more stable. Summary of the Invention
[0006] An object of the present invention is to make the movement of a stretching rod sliding in a through hole formed in a blow mold core more stable.
[0007] The present invention completed based on this object is a stretching rod sliding mechanism, characterized by having: a stretching rod that outputs a fluid for stretching an intermediate molded product by blow molding from a front end portion; a stretching plate joined to the stretching rod and moving axially along the stretching rod; a blow mold core portion having a through hole that guides the stretching rod that moves axially as the stretching plate moves; and a guiding member that penetrates the stretching plate axially along the stretching rod and guides the stretching plate that moves axially along the stretching rod.
[0008] Here, the guiding member may be a cylindrical member fixed at both ends.
[0009] Moreover, a preset first gap may be formed between the stretching rod in the through hole and the blow molding core part. A preset second gap may be formed between the guiding member and the stretching plate at the part where the guiding member penetrates through the stretching plate. A third gap serving as a clearance may be formed at the joint between the stretching rod and the stretching plate.
[0010] Moreover, the first gap and the second gap may be smaller than the third gap respectively.
[0011] Moreover, the present invention relates to an intermediate mold having a stretching rod sliding mechanism. The intermediate mold is characterized in that the stretching rod sliding mechanism includes: a stretching rod that outputs a fluid for stretching an intermediate molded product through blow molding from a front end portion; a stretching plate that engages with the stretching rod and moves along the axial direction of the stretching rod; a blow molding core part that is formed with a through hole for guiding the stretching rod that moves axially along with the movement of the stretching plate; and a guiding member that penetrates through the stretching plate along the axial direction of the stretching rod and guides the stretching plate that moves along the axial direction of the stretching rod.
[0012] Moreover, the present invention relates to a mold device including a fixed-side mold, a movable-side mold, and an intermediate mold having a stretching rod sliding mechanism. The mold device is characterized in that the stretching rod sliding mechanism of the intermediate mold includes: a stretching rod that outputs a fluid for stretching an intermediate molded product through blow molding from a front end portion; a stretching plate that engages with the stretching rod and moves along the axial direction of the stretching rod; a blow molding core part that is formed with a through hole for guiding the stretching rod that moves axially along with the movement of the stretching plate; and a guiding member that penetrates through the stretching plate along the axial direction of the stretching rod and guides the stretching plate that moves along the axial direction of the stretching rod.
[0013] Advantages of the Invention
[0014] According to the present invention, it is possible to make the movement of the stretching rod sliding in the through hole formed in the blow molding core more stable. Description of the Drawings
[0015] Figure 1 FIG. is an example showing a partial structure of a mold device including an intermediate mold having a stretching rod sliding mechanism according to the present embodiment.
[0016] Figure 2 FIG. is an example showing a partial structure of the stretching rod sliding mechanism.
[0017] Figure 3 FIG. is a diagram showing the position of the gaps formed in the stretching rod sliding mechanism.
[0018] In the figure: 10 - Mold device, 11 - Fixed-side mold, 12 - Intermediate mold, 13 - Movable-side mold, 21 - Fixed pressure plate, 22 - Fixed mold, 23 - Driving device, 31 - Rotating frame, 32 - Support frame, 33 - Injection core frame, 34 - Blow molding core frame, 35 - Gripping mechanism, 36 - Sliding frame, 37 - Guide rod, 38 - Shaft body, 39 - Driving device, 41 - Movable pressure plate, 42 - Movable split mold, 43 - Driving device, 51 - First gap, 52 - Second gap, 53 - Third gap, 61, 62, 63 - Through holes, 100 - Tensile rod sliding mechanism, 221 - Injection cavity, 341 - Blow molding core, 342 - Tensile plate, 343 - Tensile rod, 344 - Guide rod, 421 - Blow molding cavity. Detailed implementation mode
[0019] Hereinafter, with reference to the accompanying drawings, the implementation modes of the present invention will be described in detail.
[0020] <Structure of the mold device>
[0021] Figure 1 It is a diagram showing an example of a partial structure of a mold device 10 of an intermediate mold 12 equipped with a tensile rod sliding mechanism 100 according to the present implementation mode.
[0022] Figure 2 It is a diagram showing an example of a partial structure of the tensile rod sliding mechanism 100. In addition, Figure 2 It is the above-mentioned Figure 1 An enlarged view of the area 500 surrounded by a dotted line.
[0023] Figure 1 The mold device 10 shown constitutes a mold device of an injection molding machine for injection blow molding. Injection blow molding is a molding method that performs injection molding (hereinafter referred to as "injection molding") and blow molding (hereinafter referred to as "blow molding") in two stages. In injection blow molding, a preform (not shown) as an intermediate molded product is molded by injection molding, and high-pressure air is blown into the preform and expanded by blow molding, thereby molding a container or the like as the final molded product.
[0024] In the present implementation mode, as a method of blowing high-pressure air into the preform in blow molding during injection blow molding, a tensile rod 343 capable of outputting high-pressure air described later protrudes into the preform. The direction in which the tensile rod 343 protrudes into the preform is Figure 1 The direction from the left side to the right side of the drawing in Figure 1 , the axial direction of the tensile rod 343, and the opening and closing direction of the mold device. Hereinafter, the direction in which the tensile rod 343 protrudes into the preform ( Figure 1The left side of the attached drawing in Figure 1 is referred to as the "first side in the opening and closing direction", and
[0025] The mold device 10 is configured to include a fixed-side mold 11, an intermediate mold 12, and a movable-side mold 13. The mold device 10 performs injection molding by closing the intermediate mold 12 and the fixed-side mold 11. Further, the mold device 10 performs blow molding by closing the intermediate mold 12 and the movable-side mold 13.
[0026] The fixed-side mold 11 constituting the mold device 10 has a fixed platen 21, a fixed mold 22, and a drive device 23. The fixed platen 21 is a metal component that supports the fixed mold 22. The fixed mold 22 is a mold for performing injection molding and has an injection cavity 221. The drive device 23 is provided on the second side in the opening and closing direction with respect to the fixed platen 21, which is a device for moving the intermediate mold 12 relative to the fixed platen 21 in the opening and closing direction, and an unillustrated injection device for injecting a molten resin, which is a material for the preform produced by injection molding.
[0027] The intermediate mold 12 constituting the mold device 10 is a so-called rotary mold disposed between the fixed-side mold 11 and the movable-side mold 13. The intermediate mold 12 closes and opens at positions facing the fixed-side mold 11 and the movable-side mold 13, respectively. The intermediate mold 12 has: a rotary frame 31 that rotates about an axis orthogonal to the opening and closing direction and rotates circumferentially along the outer side of the shaft body 38; and a support frame 32 that supports the shaft body 38. Further, the intermediate mold 12 has: an injection core 331 that serves as a core in injection molding; an injection core frame 33 that supports the injection core 331; a blow molding core 341 that serves as a core in blow molding; and a blow molding core frame 34 that supports the blow molding core 341.
[0028] Further, the intermediate mold 12 has: a stretching plate 342 that moves in the opening and closing direction; a stretching rod 343 that moves in the opening and closing direction as the stretching plate 342 moves; and a guide rod 344 that guides the movement of the stretching plate 342. The intermediate mold 12 also has a gripping mechanism 35, a sliding frame 36, and a guide rod 37 that rotate together with the rotary frame 31. Further, the intermediate mold 12 has: a shaft body 38 that has a central axis in a direction orthogonal to the axial direction of the stretching rod 343; and a drive device 39 that rotates the rotary frame 31.
[0029] The blow molding core frame 34 that constitutes the intermediate mold 12 is a metal component that supports the blow molding core 341 by welding or the like as a part of the blow molding core portion. Inside the blow molding core frame 34, a stretching plate 342, stretching rods 343, and guide rods 344 are arranged. The blow molding core frame 34, the blow molding core 341, the stretching plate 342, the stretching rods 343, and the guide rods 344 function as elements constituting the stretching rod sliding mechanism 100 according to the present embodiment.
[0030] The blow molding core 341 that constitutes the intermediate mold 12 is a mold component that serves as the core in blow molding. When the mold device 10 is closed, it abuts against the blow molding cavity 421 of the movable split mold 42 that can open and close in a direction orthogonal to the opening and closing direction of the mold device 10, forming a space for injection molding. And when the mold device 10 is opened, the blow molding core 341 separates from the blow molding cavity 421 of the movable split mold 42. Additionally, Figure 1 shows the state where the mold device 10 is opened. Therefore, the blow molding core 341 separates from the blow molding cavity 421, and the movable split mold 42 also opens.
[0031] The stretching plate 342 that constitutes the intermediate mold 12 is a metal plate arranged to be movable in the opening and closing direction (the axial direction of the stretching rod 343) inside the blow molding core frame 34. The first-side end 352 in the opening and closing direction (axial direction) of the stretching rod 343 is joined to the stretching plate 342. Therefore, when the stretching plate 342 moves in the opening and closing direction (axial direction), accordingly, the stretching rod 343 also moves in the opening and closing direction (the axial direction of the stretching rod 343). Since the end portions 352 of the plurality of stretching rods 343 are joined to the stretching plate 342, by moving the stretching plate 342 in the opening and closing direction (the axial direction of the stretching rod 343), the plurality of stretching rods 343 can be moved simultaneously in the opening and closing direction (axial direction). The stretching plate 342 operates using a drive device (not shown) composed of a pneumatic cylinder device or the like as a drive source and moves in the opening and closing direction (the axial direction of the stretching rod 343).
[0032] The stretching rod 343 that constitutes the intermediate mold 12 is a metal component capable of outputting high-pressure air for stretching a preform through blow molding from the front end portion 351. As Figure 2 shown, the end portion 352 of the stretching rod 343 on the side opposite to the front end portion 351 is joined to the stretching plate 342. Therefore, when the stretching plate 342 moves toward the second side in the opening and closing direction (the axial direction of the stretching rod 343), accordingly, the stretching rod 343 also moves toward the second side in the opening and closing direction (axial direction), causing the front end portion 351 to protrude into the preform. A part of the stretching rod 343 including the front end side (the second side in the opening and closing direction (axial direction)) of the front end portion 351 slidably penetrates through a through hole 61 formed in the blow molding core 341 and the blow molding core frame 34 and extending in the opening and closing direction (the axial direction of the stretching rod 343).
[0033] Here, a method of joining the tension rod 343 and the tension plate 342 will be described. As Figure 2 shown, a through hole 62 including a small-diameter portion 354, a medium-diameter portion 355, and a large-diameter portion 356 is formed in the tension plate 342 in stages from the second side in the opening / closing direction (axial direction of the tension rod 343) toward the first side. In contrast, the diameter of the main body portion 350 of the tension rod 343 is smaller than the diameter of the small-diameter portion 354. Also, the end portion 352 of the tension rod 343 has a flange shape. Therefore, the diameter of the flange portion of the end portion 352 is larger than the diameter of the small-diameter portion 354, but smaller than the diameters of the medium-diameter portion 355 and the large-diameter portion 356, respectively.
[0034] If the tension rod 343 is inserted through the through hole 62 from the first side in the opening / closing direction (axial direction of the tension rod 343) toward the second side, the flange portion of the end portion 352 cannot pass through the small-diameter portion 354 and stays in the medium-diameter portion 355. At this time, the tension rod 343 is in a free state on the first side in the opening / closing direction (axial direction), so the metal block member 353 is filled in the space formed in the large-diameter portion 356. Thus, the tension rod 343 is fixed in the opening / closing direction (axial direction). In this way, the tension rod 343 and the tension plate 342 are joined.
[0035] As Figure 2 shown, the guide rod 344 constituting the intermediate die 12 is a cylindrical metal member whose both ends are fixed in a state of passing through the through hole 63 formed in the tension plate 342 along the opening / closing direction (axial direction of the tension rod 343). Specifically, in the guide rod 344, as Figure 1 shown, the end portion on the first side in the opening / closing direction (axial direction) is fixed to the injection core frame 33, and the end portion on the second side in the opening / closing direction (axial direction) is fixed to the blow molding core frame 34. The guide rod 344 functions as a guide member for guiding the tension plate 342 that moves in the opening / closing direction (axial direction of the tension rod 343).
[0036] The method of fixing both ends of the guide rod 344 is not particularly limited. As long as the guide rod 344 can be firmly fixed so as not to loosen, for example, bolts can be used for fixing, or welding can be used for fixing. In addition, in the present embodiment, bolts 361 (refer to Figure 2 ) that penetrate the guide rod 344 in the length direction (opening / closing direction) are used to fix both ends of the guide rod 344 to the injection core frame 33 and the blow molding core frame 34 (refer to Figure 1 ). Specifically, although not shown, the end portion on the first side in the opening / closing direction of the guide rod 344 is fixed to the injection core frame 33 by the combination of the external thread formed on the end portion on the first side in the opening / closing direction of the bolt 361 and the internal thread formed on the surface on the second side in the opening / closing direction of the injection core frame 33.
[0037] The gripping mechanism 35 that forms the intermediate mold 12 is a mechanism that grips the outer periphery of the mouth portion of the preform and the final molded product. The sliding frame 36 that forms the intermediate mold 12 is a member that is mounted so as to be slidable in the axial direction of the guide rod 37 and supports the gripping mechanism 35. When the sliding frame 36 slides on the guide rod 37, the gripping mechanism 35 also moves accordingly. The guide rod 37 that forms the intermediate mold 12 is a cylindrical member with one end fixed to the rotary frame 31, and the sliding frame 36 is slidably mounted on the other end side. The guide rod 37 guides the sliding of the sliding frame 36.
[0038] The shaft body 38 that forms the intermediate mold 12 is a cylindrical metal member that is joined to the support frame 32, the injection core frame 33, and the blow molding core frame 34. The drive device 39 that forms the intermediate mold 12 is a device that serves as a drive source for rotating the rotary frame 31 and is constituted by, for example, a motor or the like. When the rotary frame 31 rotates, the guide rod 37, the sliding frame 36, and the gripping mechanism 35 also rotate and alternately move between the position for injection molding and the position for blow molding.
[0039] The movable mold 13 that forms the mold device 10 has a movable platen 41, a movable split mold 42, and a drive device 43. The movable platen 41 is a metal member that supports the movable split mold 42. A mold closing and opening device (not shown) for closing and opening the mold device 10 is provided on the second side in the opening and closing direction with respect to the movable platen 41. The movable split mold 42 is a split mold for performing blow molding and has a blow molding cavity 421. The drive device 43 is a device that serves as a drive source for opening and closing the movable split mold 42 in the opening and closing direction.
[0040] In the mold device 10, for blow molding of the preform injection-molded, the stretching rod 343 protrudes into the preform, and high-pressure air is blown in, thereby stretching the preform to mold a final molded product such as a container. At this time, when the stretching rod 343 protrudes into the preform, the above-described stretching rod sliding mechanism 100 comes into play. In addition, an air flow path or air output holes (not shown) for supplying high-pressure air for blow molding are formed between the blow molding core 341, the stretching rod 343, or between them.
[0041] <Clearance formed in the stretching rod sliding mechanism>
[0042] Figure 3 (A) to Figure 3 (C) are diagrams showing the positions of the clearances formed in the stretching rod sliding mechanism 100. Figure 3 (A) is an enlarged view of the region 501 surrounded by the dotted line in the above Figure 2 and shows the position of the first clearance 51 formed between the stretching rod 343, the blow molding core 341, and the blow molding core frame 34. Figure 3 (B) is the aboveFigure 2 An enlarged view of the area 502 surrounded by a dashed line, showing the position of the second gap 52 formed between the guide rod 344 and the stretching plate 342. Figure 3 In (C) above Figure 2 An enlarged view of the area 503 surrounded by a dashed line, showing the position of the third gap 53 formed between the stretching rod 343 and the stretching plate 342.
[0043] As Figure 3 As shown in (A) above, a first gap 51 is formed between the stretching rod 343, the blow molding core 341, and the blow molding core frame 34. The first gap 51 enables the stretching rod 343 to slide in the through hole 61. The structure forming the first gap 51 is such that the size of the first gap 51 falls within a preset range. Specifically, it is designed such that the diameter of the main body portion 350 of the stretching rod 343 is slightly smaller than the diameter of the through hole 61.
[0044] And, as Figure 3 As shown in (B) above, a second gap 52 is formed between the guide rod 344 and the stretching plate 342. The second gap 52 enables the stretching plate 342 to slide relative to the guide rod 344. The structure forming the second gap 52 is such that the size of the second gap 52 falls within a preset range. Specifically, it is designed such that the diameter of the guide rod 344 is slightly smaller than the diameter of the through hole 63 formed in the stretching plate 342.
[0045] And, as Figure 3 As shown in (C) above, a third gap 53 is formed between the stretching rod 343 and the stretching plate 342. The third gap 53 functions as a clearance between the stretching rod 343 and the stretching plate 342. The structure forming the third gap 53 is such that the size of the third gap 53 falls within a preset range. Specifically, it is designed such that the diameter of the main body portion 350 of the stretching rod 343 is slightly smaller than the diameter of the small diameter portion 354 of the through hole 62 formed in the stretching plate 342.
[0046] The stretching rod sliding mechanism 100 according to the present embodiment is designed as follows: considering the relationship between the structure forming the first gap 51, the structure forming the second gap 52, and the structure forming the third gap 53. Specifically, it is designed such that the first gap 51 and the second gap 52 are each smaller than the third gap 53. That is, it is designed such that the difference between the diameter of the main body portion 350 of the stretching rod 343 and the diameter of the through hole 61 is smaller than the difference between the diameter of the main body portion 350 of the stretching rod 343 and the diameter of the small diameter portion 354 of the through hole 62. That is, it is designed such that the diameter of the through hole 61 is smaller than the diameter of the small diameter portion 354 of the through hole 62. And, it is designed such that the difference between the diameter of the guide rod 344 and the diameter of the through hole 63 is smaller than the difference between the diameter of the main body portion 350 of the stretching rod 343 and the diameter of the small diameter portion 354 of the through hole 62.
[0047] In a structure where the first gap 51 and the second gap 52 are respectively smaller than the third gap 53, the relationship between the structure forming the first gap 51 and the structure forming the second gap 52 becomes a mutually restrictive relationship. In contrast, in the tension rod sliding mechanism 100 according to the present embodiment, a third gap 53 serving as a clearance is formed, so that the restriction on the structure forming the first gap 51 and the restriction on the structure forming the second gap 52 can be taken into account. That is, in the tension rod sliding mechanism 100, a third gap 53 serving as a clearance is formed, thereby ensuring the first gap 51 for stably sliding the tension rod 343 in the opening and closing direction (axial direction) and the second gap 52 for stably moving the tension plate 342 in the opening and closing direction (axial direction of the tension rod 343).
[0048] In summary, the tension rod sliding mechanism, the intermediate mold, and the mold device applying the present invention can adopt the following structures and can adopt various embodiments.
[0049] That is, the tension rod sliding mechanism 100 according to the present embodiment is a tension rod sliding mechanism characterized by having: a tension rod 343 that outputs a fluid (for example, high-pressure air) for stretching a preform as an intermediate molded product through blow molding from a front end portion 351; a tension plate 342 that is joined to the tension rod 343 and moves along the axial direction of the tension rod 343; a blow molding core 341 and a blow molding core frame 34 that form a through hole 61 for guiding the tension rod 343 that moves axially along with the movement of the tension plate 342; and a guide rod 344 as a guiding member that axially penetrates the tension plate 342 along the tension rod 343 and guides the tension plate 342 that moves along the axial direction of the tension rod 343.
[0050] Thereby, the guide rod 344 that axially penetrates the tension plate 342 guides the tension plate 342 that moves in the axial direction of the tension rod 343, so that the movement of the tension plate 342 and the movement of the tension rod 343 joined to the tension plate 342 can be stabilized. As a result, "eccentricity" that causes unevenness or channel deviation can be suppressed, and moreover, generation of abrasive powder due to friction between the blow molding core 341 and the blow molding core frame 34 and the tension rod 343, or die biting of the mold can be suppressed.
[0051] Here, the guide rod 344 may be a cylindrical member fixed at both ends.
[0052] Thereby, the guide rod 344, which is a cylindrical member fixed at both ends, guides the tension plate 342 that moves in the axial direction of the tension rod 343, so that the movement of the tension plate 342 can be stabilized. As a result, the movement of the tension rod 343 joined to the tension plate 342 can be stabilized.
[0053] Moreover, a preset first gap 51 can be formed between the tension rod 343 in the through-hole 61 and the blowing core 341 and the blowing core frame 34. In the through-hole 63 which is the part where the guiding rod 344 penetrates the tension plate 342, a preset second gap 52 is formed between the guiding rod 344 and the tension plate 342. A third gap 53 which serves as a clearance is formed at the joint between the tension rod 343 and the tension plate 342.
[0054] Thus, the following design can be carried out: taking into account the relationship between the structure of the first gap 51 required for the sliding of the tension rod 343, the structure of the second gap 52 required for the sliding of the guiding rod 344, and the structure of the third gap 53 which serves as a clearance. Therefore, for example, even if the structure of the first gap 51 and the structure of the second gap 52 are in a mutually restrictive relationship with each other, since the third gap 53 which serves as a clearance is formed, it is possible to take into account both the restriction on the structure of the first gap 51 and the restriction on the structure of the second gap 52. As a result, a first gap 51 for stably sliding the tension rod 343 and a second gap 52 for stably moving the tension plate 342 in the axial direction (opening and closing direction) of the tension rod 343 can be formed. Moreover, since the third gap 53 which serves as a clearance is deliberately formed, the assembly for joining the tension rod 343 and the tension plate 342 can be simplified.
[0055] Moreover, the first gap 51 and the second gap 52 can be respectively smaller than the third gap 53.
[0056] Thus, since the first gap 51 and the second gap 52 are respectively smaller than the third gap 53, the structure of the first gap 51 and the structure of the second gap 52 are in a mutually restrictive relationship with each other. In contrast, the third gap 53 can be increased to take into account both the restriction on the structure of the first gap 51 and the restriction on the structure of the second gap 52. As a result, a first gap 51 for stably sliding the tension rod 343 and a second gap 52 for stably moving the tension plate 342 in the axial direction (opening and closing direction) of the tension rod 343 can be formed. Moreover, since the third gap 53 which serves as a clearance is deliberately formed, the assembly for joining the tension rod 343 and the tension plate 342 can be simplified.
[0057] Moreover, the intermediate die applying the present invention only needs to adopt the following structure and can adopt various implementation manners.
[0058] That is, the intermediate mold 12 according to the present embodiment is an intermediate mold having a stretching rod sliding mechanism 100. The intermediate mold 12 is characterized in that the stretching rod sliding mechanism 100 includes: a stretching rod 343 that outputs a fluid for stretching a preform as an intermediate molded product by blow molding from a front end portion 351; a stretching plate 342 that engages with the stretching rod 343 and moves in the axial direction of the stretching rod 343; a blow molding core 341 and a blow molding core frame 34 that form a through hole 61 for guiding the stretching rod 343 that moves in the axial direction along with the movement of the stretching plate 342; and a guide rod 344 as a guiding member that penetrates the stretching plate 342 in the axial direction of the stretching rod 343 and guides the stretching plate 342 that moves in the axial direction of the stretching rod 343.
[0059] Thus, the guide rod 344 that penetrates the stretching plate 342 in the axial direction of the stretching rod 343 guides the stretching plate 342 that moves in the axial direction of the stretching rod 343. Therefore, the movement of the stretching plate 342 and the movement of the stretching rod 343 that engages with the stretching plate 342 can be stabilized. As a result, "eccentricity" that causes unevenness or channel deviation can be suppressed, and moreover, generation of abrasive powder due to friction between the blow molding core 341 and the blow molding core frame 34 and the stretching rod 343, or die biting of the mold can be suppressed.
[0060] Moreover, the mold device applying the present invention can adopt various embodiments as long as it has the following structure.
[0061] That is, the mold device 10 according to the present embodiment is a mold device that includes a fixed-side mold 11, a movable-side mold 13, and an intermediate mold 12 having a stretching rod sliding mechanism 100. The mold device is characterized in that the stretching rod sliding mechanism 100 of the intermediate mold 12 includes: a stretching rod 343 that outputs a fluid for stretching a preform as an intermediate molded product by blow molding from a front end portion 351; a stretching plate 342 that engages with the stretching rod 343 and moves in the axial direction of the stretching rod 343; a blow molding core 341 and a blow molding core frame 34 that form a through hole 61 for guiding the stretching rod 343 that moves in the axial direction along with the movement of the stretching plate 342; and a guide rod 344 as a guiding member that penetrates the stretching plate 342 in the axial direction of the stretching rod 343 and guides the stretching plate 342 that moves in the axial direction of the stretching rod 343.
[0062] Thus, the guide rod 344 that penetrates the stretching plate 342 in the axial direction of the stretching rod 343 guides the stretching plate 342 that moves in the axial direction of the stretching rod 343. Therefore, the movement of the stretching plate 342 and the movement of the stretching rod 343 that engages with the stretching plate 342 can be stabilized. As a result, "eccentricity" that causes unevenness or channel deviation can be suppressed, and moreover, generation of abrasive powder due to friction between the blow molding core 341 and the blow molding core frame 34 and the stretching rod 343, or die biting of the mold can be suppressed.
[0063] <Other>
[0064] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. Moreover, the effects based on the present invention are not limited to the effects described in the above embodiments. For example, Figure 1 the structure of the die device 10 shown, Figure 2 the structure of the tension rod sliding mechanism 100 shown, Figure 3 the positions of the gaps shown are merely examples for achieving the object of the present invention and are not particularly limited.
[0065] For example, in the above embodiment, as Figure 1 shown, at least two guide rods 344 are provided, but the number of the guide rods 344 is not limited. The guide rod 344 may be one, or may be three or more.
[0066] Moreover, in the above embodiment, the shape of the guide rod 344 is cylindrical, but it is not limited thereto. For example, it may also be prismatic.
Claims
1. A stretching rod sliding mechanism, characterized in that: have: A stretching rod that outputs fluid from the front end to stretch the intermediate molded product through blow molding; A stretching plate, engaged with the stretching rod and moving along the axial direction of the stretching rod; A blow core having a through hole formed therein for guiding the stretch rod that moves in the axial direction accompanying the movement of the stretch plate; and The guide component penetrates the stretching plate along the axial direction of the stretching rod and guides the stretching plate to move along the axial direction of the stretching rod.
2. The stretching rod sliding mechanism according to claim 1, characterized in that: The guide component is a cylindrical component with both ends fixed.
3. The stretching rod sliding mechanism according to claim 1, characterized in that: A predetermined first gap is formed between the stretch rod and the blow molding core in the through hole. At a portion where the guide member passes through the stretch plate, a predetermined second gap is formed between the guide member and the stretch plate. A third gap serving as play is formed at a joint between the stretch rod and the stretch plate.
4. The stretching rod sliding mechanism according to claim 3, characterized in that: The first gap and the second gap are respectively smaller than the third gap.
5. An intermediate mold having a stretch rod sliding mechanism, wherein the intermediate mold is characterized in that: The stretching rod sliding mechanism comprises: A stretching rod that outputs fluid from the front end to stretch the intermediate molded product through blow molding; A stretching plate, engaged with the stretching rod and moving along the axial direction of the stretching rod; A blow core having a through hole formed therein for guiding the stretch rod that moves in the axial direction accompanying the movement of the stretch plate; and The guide component penetrates the stretching plate along the axial direction of the stretching rod and guides the stretching plate to move along the axial direction of the stretching rod.
6. A mold device comprising a fixed side mold, a movable side mold, and an intermediate mold having a stretch rod sliding mechanism, wherein the mold device is characterized in that: The stretch rod sliding mechanism of the intermediate mold has: A stretching rod that outputs fluid from the front end to stretch the intermediate molded product through blow molding; A stretching plate, engaged with the stretching rod and moving along the axial direction of the stretching rod; A blow core having a through hole formed therein for guiding the stretch rod that moves in the axial direction accompanying the movement of the stretch plate; and The guide component penetrates the stretching plate along the axial direction of the stretching rod and guides the stretching plate to move along the axial direction of the stretching rod.