JP2024033268A - Molds for molding resin containers and injection blow molding machines - Google Patents

Abstract

An object of the present invention is to provide a mold for molding a resin container with a flange-like opening that prevents burrs. SOLUTION: The mold is composed of an injection mold (38), a blow mold (39), and an intermediate mold (41). When the injection molding die (38) and the intermediate die (41) are clamped and the injection is performed, a flange-shaped opening (64) formed from the first annular step (44) and the annular surface (48) is formed. ) is molded. When the parison (62) is left in the intermediate mold (41) and the blow molding mold (39) is clamped, the flange-shaped opening (64) is formed by the second annular step (58) and the annular surface (48). ) is compressed. The first annular step (44) includes an outer peripheral surface forming side wall surface (45) for forming the outer peripheral surface (67) of the flange-shaped opening (64), and this is connected to the parting line (PL). has been done. The second annular step (58) includes an outer circumferential surface contacting side wall surface (60) that contacts the outer circumferential surface (67), and this is connected to the parting line (PL). [Selection diagram] Figure 3F

Description

The present invention relates to a mold for molding a parison by injection molding, and a mold for molding a resin container having a flange-shaped opening by blow molding, which supplies compressed air to the parison, and an injection blow molding machine. It is related to.

2. Description of the Related Art Resin containers equipped with a flange-shaped opening are widely used as containers for storing and sealing beverages, foods, and the like. Food, etc. is stored in a resin container, and a film-like lid is attached to the flange-like opening. In this way, foods and the like can be sealed and distributed hygienically.

A resin container with a flange-shaped opening can be molded using an injection mold, as described in Patent Document 1, for example. That is, the mold includes an injection mold in which a recess is formed, an intermediate mold including a core, and a blow molding mold in which a recess is formed. First, an injection mold and an intermediate mold are clamped, and resin is injected to form a parison. The mold is then opened with the parison remaining in the core of the intermediate mold. The intermediate mold and the blow molding mold are aligned and clamped. Then, the parison is sandwiched between the blow molding die and the intermediate die. When compressed air is supplied to the parison, a resin container with a flange-like opening is formed.

Special Publication No. 46-18632

The flange-like opening of the resin container is formed in a parison formed by an injection mold and an intermediate mold, and the flange-shaped opening is formed by molding the parison with a blow-molding mold and an intermediate mold. I'm trying to sandwich it in. Since the resin contracts as the temperature decreases, the flange-shaped opening is previously formed to have a slightly larger volume during injection molding. Then, when the blow molding die and the intermediate die press down on the flange-shaped opening of the parison, it will be compressed. This can prevent sink marks from occurring at the flange-shaped opening of the resin container. However, when the flange-shaped opening of the parison is pressed down between the blow-molding die and the intermediate die, there is a risk that the resin at the flange-shaped opening may leak out from the parting line between the blow-molding die and the intermediate die. In other words, there is a possibility that burrs may be formed.

The present disclosure provides a mold for molding a resin container with a flange-like opening that prevents the occurrence of burrs.

Other objects and novel features will become apparent from the description of this specification and the accompanying drawings.

The present disclosure provides an injection mold that includes a first recess and a first annular step around the first recess, and a plurality of split molds that, when combined, form a second recess and a second annular step. The intermediate mold includes a blow molding mold in which a part is formed, and an intermediate mold having a core in which compressed air holes are formed and an annular surface part surrounding the core. A parison is formed by clamping the injection mold and the intermediate mold and injecting the parison, and a flange-shaped opening is formed from the first annular step and the annular surface. The blow molding mold and the intermediate mold are clamped together, and the flange-shaped mouth part is compressed by the second annular step part and the annular surface part. The cavity formed has a smaller volume. Further, in the present disclosure, the first annular step portion includes an outer circumferential surface forming side wall surface for forming the outer circumferential surface of the flange-shaped opening of the parison, and the second annular step portion has an outer circumferential surface in contact with the outer circumferential surface. Equipped with a wall surface for surface contact. The side wall surface for forming the outer peripheral surface and the wall surface for contacting the outer peripheral surface are connected to the parting line.

The present disclosure can prevent the occurrence of burrs.

FIG. 1 is a front view of an injection blow molding machine according to a first embodiment. FIG. 2 is a front view showing a part of the injection blow molding machine and a part of the molding die according to the first embodiment. FIG. 2 is a front sectional view showing an injection mold and an intermediate mold of the mold according to the first embodiment. FIG. 2 is a front sectional view showing an injection mold and an intermediate mold of the mold according to the first embodiment. It is a front sectional view showing an injection mold of a molding die concerning a 1st embodiment, an intermediate mold, and a parison formed by injection molding. FIG. 2 is a front sectional view showing an injection mold, an intermediate mold, and a parison of the mold according to the first embodiment. FIG. 2 is a front sectional view showing a blow molding mold, an intermediate mold, and a parison of the molding mold according to the first embodiment. FIG. 2 is a front sectional view showing a blow molding mold, an intermediate mold, and a parison of the molding mold according to the first embodiment. FIG. 2 is a front sectional view showing a blow molding mold, an intermediate mold, and a parison of the molding mold according to the first embodiment. FIG. 2 is a front sectional view showing a blow molding mold, an intermediate mold, and a resin container of the molding mold according to the first embodiment. FIG. 2 is a front sectional view showing a blow molding mold, an intermediate mold, and a resin container of the molding mold according to the first embodiment. FIG. 3 is a front sectional view showing a part of a blow molding mold, an intermediate mold, and a parison of the molding mold according to the first embodiment. FIG. 3 is a front sectional view showing a part of a blow molding mold, an intermediate mold, and a parison of the molding mold according to the first embodiment. FIG. 3 is a front sectional view showing a part of a blow molding mold, an intermediate mold, and a parison of a molding mold according to a comparative example. FIG. 3 is a front sectional view showing a part of a blow molding mold, an intermediate mold, and a parison of a molding mold according to a comparative example. It is a front sectional view showing a part of an injection mold and an intermediate mold of a molding mold concerning a 2nd embodiment. It is a side view of the parison injection-molded with the molding die based on 2nd Embodiment. FIG. 6B is a cross-sectional view of a parison injection-molded using a molding die according to a second embodiment, taken along the cross-section XX in FIG. 6B. FIG. 7 is a cross-sectional view of a parison according to a first modification of the second embodiment. FIG. 7 is a cross-sectional view of a parison according to a second modification of the second embodiment. It is a front sectional view showing a part of a blow molding die of a molding die concerning a modification of a 1st embodiment, an intermediate die, and a parison, respectively.

Hereinafter, specific embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. For clarity of explanation, the following description and drawings have been simplified where appropriate. In each drawing, the same elements are denoted by the same reference numerals, and redundant explanation will be omitted as necessary. In addition, hatching is omitted in some parts to avoid cluttering the drawings.

[First embodiment]
<Injection blow molding machine>
An injection blow molding machine 1 according to a first embodiment is shown in FIG. The injection blow molding machine 1 controls a mold clamping device 2 that clamps a molding die 30, which will be explained later, an injection device 3 that injects resin, and a compressed air supply device 5 that supplies compressed air. A controller 4 is provided.

<Mold clamping device>
The mold clamping device 2 includes a fixed platen 7 fixed to the bed B, and a plurality of mold plates slidably provided on the bed B. That is, a movable platen 8, a mold clamping housing 9, and an intermediate platen 10 provided between the fixed platen 7 and the movable platen 8. The fixed platen 7 and the mold clamping housing 9 are connected by a plurality of tie bars 11, 11, . A mold clamping mechanism, that is, a toggle mechanism 13 in this embodiment, is provided between the movable platen 8 and the mold clamping housing 9. Therefore, when the toggle mechanism 13 is driven, the movable platen 8 is driven in the left-right direction.

In the first embodiment, the intermediate disk 10 includes an intermediate disk support 15 and an intermediate disk main body 16 that is supported rotatably, that is, reversibly, with respect to the intermediate disk support 15. An intermediate plate opening/closing mechanism 17 is provided between the intermediate plate support 15 and the movable plate 8 for driving the intermediate plate 10 in the direction away from and toward the movable plate 8. Therefore, when the toggle mechanism 13 and the intermediate plate opening/closing mechanism 17 are driven in conjunction with each other, the molding die 30, which will be described later, can be clamped, and when similarly driven in conjunction with each other, the mold can be opened. It has become.

<Injection device>
The injection device 3 includes a heating cylinder 19, a screw 20 provided in the heating cylinder 19, and a drive mechanism 22 that drives the screw 20. The heating cylinder 19 is provided with a hopper 23 to which injection material is supplied. Further, an injection nozzle 24 is provided at the tip of the heating cylinder 19.

<Mold>
The molding die 30 according to the first embodiment is composed of a plurality of die groups. That is, an injection mold group 31 provided on the fixed plate 7, a blow mold group 32 provided on the movable plate 8, and a mold group 32 provided on one surface of the intermediate plate body 16. One intermediate mold group 34 and a second intermediate mold group 35 provided on the other surface. Although a part of the mold clamping device 2 and a part of the molding die 30 are shown in FIG. 2, the injection mold group 31 includes a plurality of injection molds 38, 38, . . . It consists of The blow molding mold group 32 includes the same number of blow molding molds 39, 39, . . . as the injection molding molds 38, 38, . . . of the injection molding mold group 31. Similarly, the first intermediate mold group 34 is comprised of the same number of intermediate molds 41, 41, . . . , and the second intermediate mold group 35 is also comprised of the same number of intermediate molds 41, 41, . .

When the intermediate plate 10 is placed in the position shown in FIG. 2, that is, in the first inverted position, and the molds are clamped, the injection mold group 31 and the first intermediate mold group 34 are separated, and the blow molding mold The mold group 32 and the second intermediate mold group 35 are each clamped. On the other hand, when the intermediate plate 10 is inverted, that is, in the second inverted position, and the molds are clamped, the injection mold group 31 and the second intermediate mold group 35 are separated, and then the blow mold group 32 and , and the first intermediate mold group 34 are respectively clamped.

<Injection mold>
FIG. 3A shows one injection mold 38 and one intermediate mold 41. The injection mold 38 is formed with a first recess 43 and an annular step around the first recess 43, that is, a first annular step 44. The first recess 43 is configured to form the body of the parison, and the first annular step 44 is configured to form the flange-like mouth of the parison. The first annular step portion 44 includes a cylindrical outer circumferential surface forming side wall surface 45, and the outer circumferential surface forming side wall surface 45 forms the outer circumferential surface of the flange-shaped opening. The injection mold 38 is characterized in that the outer peripheral surface forming side wall surface 45 is connected to the parting line PL. A runner 46 is connected to the first recess 43 so that resin from the injection device 3 (see FIG. 1) is injected.

<Intermediate mold>
As shown in FIG. 3A, the intermediate mold 41 has a core 47 and an annular surface surrounding the core 47, that is, an annular surface portion 48. The core 47 is provided with compressed air holes 50, 50 for supplying compressed air. The compressed air supply device 5 (see FIG. 1) is connected to the first intermediate mold group 34 and the second intermediate mold group 35, and is connected to the intermediate mold 41 (see FIG. 3A) provided in each of them. Compressed air is supplied to compressed air holes 50, 50 of. This allows blow molding to be carried out as explained later.

When the injection mold 38 and the intermediate mold 41 are clamped together, an injection molding cavity, that is, a parison molding cavity 52 is formed, as shown in FIG. 3B. . The parison molding cavity 52 is composed of two cavities. That is, the cavity 53 for forming the main body of the parison is formed by the first recess 43 and the core 47, and the flange-like shape of the parison is formed by the first annular step 44 and the annular surface 48. This is a mouth forming cavity 54 that forms a mouth. A parison with a flanged mouth can be obtained by injection molding, as will be explained later.

<Mold for blow molding>
A blow molding mold 39 is shown in FIG. 3E. The blow molding die 39 is composed of two divided dies 56 and 56 in this embodiment. In the state where the split molds 56, 56 are combined, the blow molding die 39 is formed with a second recess 57 and a second annular step 58, which is an annular step. The second recess 57 has a structure for forming a container from the parison by blow molding, and the second annular step 58 presses the flange-shaped opening of the parison to compress it. It is structured to do so. The second annular step portion 58 includes a cylindrical outer circumferential surface contacting side wall surface 60, and this outer circumferential surface contacting side wall surface 60 comes into contact with the outer circumferential surface of the flange-shaped opening. The present disclosure is characterized in that, in the blow molding die 39, the outer peripheral surface contacting side wall surface 60 is connected to the parting line PL.

<Injection blow molding method>
A method of molding a resin container using the injection blow molding machine 1 (see FIG. 1) and the molding die 30 according to the first embodiment will be described. As shown in FIG. 2, the intermediate plate 10 is placed in a first inverted position. Then, the injection mold group 31 and the first intermediate mold group 34 face each other, and the respective injection molds 38 and intermediate molds 41 are aligned, as shown in FIG. 3A. . When the molds are clamped, the injection mold 38 and the intermediate mold 41 are clamped as shown in FIG. 3B. As described above, the parison molding cavity 52 is composed of the main body forming cavity 53 and the mouth forming cavity 54.

When resin is injected from the injection device 3 (see FIG. 1) and filled into the parison molding cavity 52, a parison 62 is molded as shown in FIG. 3C. The parison 62 is composed of a main body part 63 and a flange-shaped opening part 64. The flange-shaped mouth portion 64 has a rounded end face on the opening side. Specifically, it is formed into a smooth annular protrusion 66. This is because the annular surface portion 48 is formed into a smooth concave portion. A resin container is formed from the parison 62 as will be explained later, but the annular protrusion 66 of the flange-shaped mouth 64 remains in this shape. When the film-like lid is attached to the flange-shaped opening 64 after food or the like is placed in the resin container, since the annular protrusion 66 is formed, the adhesion area becomes smaller and the adhesiveness becomes higher. Furthermore, since the adhesive area is small, an excellent effect can be obtained in that the film-like lid body can be easily peeled off.

The flange-shaped opening 64 of the parison 62 has an outer peripheral surface 67 formed into a cylindrical surface. This outer peripheral surface 67 is formed by the outer peripheral surface forming side wall surface 45 of the first annular step 44 of the injection mold 38.

The mold clamping device 2 (see FIG. 1) is driven to open the mold. Then, as shown in FIG. 3D, the injection mold 38 and the intermediate mold 41 are opened. At this time, the parison 62 is left in the core 47 of the intermediate mold 41. The intermediate board 10 (see FIGS. 1 and 2) is inverted to a second inverted position. Then, as described above, the first intermediate mold group 34 and the blow molding mold group 32 face each other. At this time, as shown in FIG. 3E, the intermediate mold 41 with the parison 62 remaining and the blow molding mold 39 face each other.

The divided molds 56, 56 are brought into a combined state and the molds are clamped. At this initial stage of mold clamping, the second annular step 58 of the blow molding die 39 contacts the flange-shaped opening 64 of the parison 62, as shown in FIG. 3F. At this time, the parting lines PL are open by a gap 69. Furthermore, when the molds are clamped, as shown in FIG. The mold 41 is compressed in a mouth compression cavity 71 made up of an annular surface 48 of the mold 41. The gap 69 (see FIG. 3F) is first formed because the opening forming cavity 54 (see FIGS. 3B and 3C) has a slightly larger capacity than the opening compression cavity 71. It is from. By compressing the flange-shaped opening 64, sinking of the annular protrusion 66 is prevented.

The operation of compressing the flange-shaped mouth portion 64 will be explained in more detail. At the initial stage of mold clamping, as explained with reference to FIG. 3F, the parting lines PL are open by a gap 69. FIG. 4A shows a part of the blow molding mold 39, a part of the intermediate mold 41, and a part of the parison 62 in an enlarged manner. When the gap 69 is opened between the parting lines PL, the back side 72 of the flange-shaped opening 64 of the parison 62 contacts the second annular step 58. Then, resin pressure is generated at a portion indicated by the reference numeral 70.

When the mold is further clamped in this state, the range indicated by reference numeral 70 expands, and the resin pressure in the range indicated by reference numeral 73 temporarily increases as shown in FIG. 4B. This is because resin has compressibility, and resin pressure increases instantaneously and locally. On the other hand, in the vicinity of the parting line PL, which is spaced apart from the back side 72 of the flange-shaped opening 64, the rise in resin pressure is slightly delayed. Therefore, resin leakage from the parting lines PL, PL can be prevented. In other words, the occurrence of burrs can be prevented. In this way, the generation of burrs at the flange-shaped opening 64 can be prevented in the second annular step 58 of the blow molding die 39, since the outer circumferential surface contacting side wall surface 60 connected to the parting line PL is This is because it is formed. This is because the outer peripheral surface contacting side wall surface 60 can slightly delay the increase in resin pressure near the parting line PL.

Note that the resin pressure becomes uniform within the flange-shaped opening 64 immediately after the mold clamping is completed. In other words, local deviations in resin pressure are eliminated. Since the flange-shaped opening 64 is compressed as described above, sink marks in this portion are prevented.

When the mold clamping is completed, compressed air is supplied from the compressed air supply device 5 (see FIG. 1). Then, as shown in FIG. 3H, compressed air is supplied from the compressed air holes 50, 50, and the main body 63 of the parison 62 is expanded. That is, it is blow molded. A resin container 74 with a flange-like opening 64 is formed. As shown in FIG. 3I, the split molds 56, 56 are opened in the blow molding die 39. Then open the mold. Then, a resin container 74 is obtained.

By the way, as can be understood from FIGS. 1 and 2, when the intermediate board 10 is placed in the second inverted position and the molds are clamped, the first intermediate mold group 34 and the blow molding mold group 32 are clamped. At the same time, the injection mold group 31 and the second intermediate mold group 35 are also clamped. That is, although it has been explained that the intermediate mold 41 of the first intermediate mold group 34 and the blow molding mold 39 are clamped with reference to FIGS. 3F, 3G, and 3H, at this time, the injection mold The group 31 and the second intermediate mold group 35 are also clamped. That is, as shown in FIG. 3B, the injection mold 38 and the intermediate mold 41 of the second intermediate mold group 35 are also clamped. Then, when performing blow molding in the first intermediate mold group 34 and the blow molding mold group 32, injection molding can be performed in the injection molding mold group 31 and the second intermediate mold group 35. can. In this way, a resin container can be molded each time the intermediate board 10 is turned over.

<Comparative example>
While the molding die 30 according to the first embodiment can appropriately prevent burrs, a molding die according to a comparative example in which burrs are likely to occur will be described. A part of a molding die 101 according to a comparative example is shown in FIG. 5A. This molding die 101 is also a die for carrying out an injection blow molding method, and is adapted to mold a resin container having a flange-shaped opening. It is used by being attached to the injection blow molding machine 1 shown in FIG. Further, the molding die 101 according to the comparative example differs only in the positions of the parting lines PL and PL, and its structure is different from that of the molding die 30 according to the first embodiment (FIGS. 3A and 3E). ) is similar to

Although FIG. 5A shows a portion of the intermediate mold 102 and blow molding mold 103 that constitute the molding mold 101, the first embodiment shown in FIG. 4A When compared with such a molding die 30, it can be seen that the positions of the parting lines PL are different. That is, the blow molding die 103 is also formed with a second annular step 105, but this second annular step 105 is directly connected to the parting line PL. The outer peripheral surface contacting side wall surface 60 provided in the blow molding mold 39 of the molding mold 30 according to the first embodiment shown in FIG. 4A does not exist. As shown in FIG. 5A, the outer peripheral surface 109 of the flange-like opening 108 of the parison 107 is formed by the intermediate mold 102. As shown in FIG.

The blow molding die 103 and the intermediate die 102 are clamped together with the parison 107 remaining in the intermediate die 102 according to the comparative example. When the second annular step 105 contacts the back side 110 of the flange-like mouth 108 as shown in FIG. 5A, the parting lines PL, PL are open. Initially, resin pressure increases at the back side 110 of the flange-shaped mouth 108, as indicated by 112. When the mold clamping is further advanced, the parting lines PL become narrower as shown in FIG. 5B. As indicated by reference numeral 113, the range of high resin pressure spreads near the parting lines PL, PL. Therefore, as indicated by reference numeral 114, the resin with increased pressure leaks from the gap between the parting lines PL and PL. In other words, burrs are generated.

In the molding die 101 according to the comparative example, burrs are likely to occur on the outer circumferential contact side of the blow molding die 39 of the molding die 30 according to the first embodiment (see FIG. 4A). This is because the wall surface 60 does not exist. In the molding die 30 according to the first embodiment, since the outer peripheral surface contacting side wall surface 60 is connected to the parting line PL, the resin pressure that increases due to the compression of the flange-shaped opening 64 is transferred to the parting line. This is because reaching the vicinity of PL can be delayed.

[Second embodiment]
A second embodiment will be described. Since the injection blow molding machine 1 according to the second embodiment is configured in the same manner as the injection blow molding machine 1 described with reference to FIG. 1, a description regarding the injection blow molding machine 1 will be omitted. In the second embodiment, a molding die 30A is different from the molding die 30 according to the first embodiment in its configuration, but the difference is that the injection molding die 38 (FIG. 3A (see) only the shape of the first annular step portion 44. That is, in the second embodiment as well, as shown in FIG. 2, the injection mold group 31, the first and second intermediate mold groups 34 and 35, and the blow mold group 32, the explanation regarding this point will also be omitted.

FIG. 6A shows a part of an injection mold 38A and an intermediate mold 41 of a mold 30A according to the second embodiment. What is different from the molding die 30 according to the first embodiment (FIG. 3B) is the shape of the first annular step 44A. In the second embodiment, a plurality of radial grooves 75, . . . are formed in the first annular step portion 44A. This point is different from the first embodiment. The intermediate mold 41 and the blow molding mold 39 (see FIG. 3E) are configured in the same manner as in the first embodiment, and therefore their description will be omitted.

The injection blow molding method in the second embodiment is substantially similar to the injection blow molding method in the first embodiment described with reference to FIGS. 3A to 3I and FIGS. 4A and 4B. Therefore, of the injection blow molding method in the second embodiment, only the points that are different from the first embodiment will be described.

When the injection mold 38A of the mold 30A according to the second embodiment and the intermediate mold 41 are clamped and injected, a parison 62A as shown in FIG. 6B is formed. FIG. 6B is a side view of the parison 62A viewed from the main body 63 side. A plurality of linear protrusions 77, 77, . . . are formed on the flange-shaped opening 64A of the parison 62A. The linear protrusions 77, 77, . . . are formed by the grooves 75, .

FIG. 6C shows a cross-sectional view of the linear protrusion 77 taken along the line XX in FIG. 6B. The linear protrusions 77, 77, . . . have trapezoidal cross sections. In other words, the width of the cross section of the linear protrusions 77, 77, . . . becomes narrower in the height direction. The reason why the striped protrusions 77, 77, . . . are formed in this manner is that the grooves 75, 75, . . . (see FIG. 6A) are narrow in width in the depth direction.

By forming these linear protrusions 77, 77, ... on the flange-like mouth 64A of the parison 62A, the volume of the flange-like mouth 64A is larger than the mouth compression cavity 71 (see FIG. 3G). . That is, as shown in FIG. 3G, when the intermediate mold 41 and the blow molding mold 39 are clamped together, the flange-like opening 64A is expanded by the capacity of these linear protrusions 77, 77, . It will be compressed.

[Second embodiment modification]
The molding die 30A (see FIG. 6A) according to the second embodiment can be deformed. Specifically, the shape of the groove 75 can be changed. FIGS. 6D and 6E show striped protrusions 77' and 77'' of the flange-like openings 64A' and 64A'' of the parisons 62A' and 62A'', respectively, formed by the deformed molding die 30A. A cross section is shown. The striated projection 77' shown in FIG. 6D has a semicylindrical cross section, and the striated projection 77'' shown in FIG. 6E has a triangular cross section. The width of the upper portion of the linear protrusions 77', 77'' according to any of the modified examples is narrow.

[Other variations]
The first and second embodiments can be modified in various ways. For example, the molding die 30 (see FIG. 4A) according to the first embodiment can be modified. FIG. 7 shows a molding die 30B including an intermediate die 41B and a blow molding die 39 according to a modification. In the intermediate mold 41B according to the modification, the annular surface portion 48B is formed in a planar shape. Therefore, the flange-shaped opening 64B of the parison 62B to be formed has an opening-side end surface 80 formed into a flat surface. In a resin container formed from this parison 62B by blow molding, the end surface 80 on the opening side of the flange-shaped opening 64B is a flat surface, so that the adhesion area of the film-shaped lid becomes large.

The first and second embodiments can be further modified. The injection mold group 31 explained with reference to FIG. 2 was explained as being composed of two or more injection molds 38, 38, . . . . The blow molding mold group 32 also includes the same number of blow molding molds 39, 39, . It was explained that it consists of... However, the injection mold group 31 is formed from one injection mold 38, the blow mold group 32 is also formed from one blow mold 39, and further from the first and second intermediate molds. The mold groups 34 and 35 may also each include one intermediate mold 41 and 41.

Although the invention made by the present inventor has been specifically explained based on the embodiments above, the present invention is not limited to the embodiments already described, and various changes can be made without departing from the gist thereof. It goes without saying that it is possible. The plurality of examples explained above can also be implemented in combination as appropriate.

1 Injection blow molding machine 2 Mold clamping device 3 Injection device 4 Controller 5 Compressed air supply device 7 Fixed plate 8 Movable plate 9 Mold clamping housing 10 Intermediate plate 11 Tie bar 13 Toggle mechanism 15 Intermediate plate support 16 Intermediate plate main body 17 Intermediate plate opening/closing Mechanism 19 Heating cylinder 20 Screw
22 Drive mechanism 23 Hopper 24 Injection nozzle 30 Molding mold 31 Injection mold group 32 Blow mold group 34 First intermediate mold group 35 Second intermediate mold group 38 Injection mold 39 Blow molding mold 41 Intermediate mold 43 First recess 44 First annular step 45 Side wall surface for forming outer peripheral surface 46 Runner 47 Core 48 Annular surface portion 50 Compressed air hole 52 Cavity for parison molding 53 Cavity for forming main body part 54 Mouth forming cavity 56 Split mold 57 Second recess 58 Second annular step 60 Side wall surface for contacting outer peripheral surface 62 Parison 63 Main body 64 Flange-shaped mouth 66 Annular protrusion 67 Outer peripheral surface 69 Gap 71 Mouth Compression cavity 72 Back side 75 Groove 77 Linear projection

Claims (17)

An injection mold comprising a first recess and a first annular step formed around the first recess;
A blow molding mold including a plurality of split molds and forming a second recess and a second annular step that is an annular step when combined;
An intermediate mold comprising a core having compressed air holes formed therein and an annular surface portion which is an annular surface formed around the core,
When the injection mold and the intermediate mold are clamped, a main body forming cavity for forming the main body of the parison from the first recess and the core is formed between the first annular step and the annular A mouth forming cavity that forms a flange-like mouth of the parison is formed from the face part, respectively,
When the blow molding mold and the intermediate mold are clamped, a mouth compression cavity is formed from the front second annular step portion and the annular surface portion to compress the flange-shaped mouth portion of the parison. It looks like this,
The volume of the mouth forming cavity is larger than that of the mouth compression cavity,
The first annular step portion includes an outer circumferential surface forming side wall surface for forming an outer circumferential surface of the flange-shaped opening of the parison, and the outer circumferential surface forming side wall surface is connected to a parting line;
The second annular stepped portion includes an outer circumferential surface contacting side wall surface that contacts the outer circumferential surface of the flange-shaped opening of the parison, and the outer circumferential surface contacting side wall surface is connected to a parting line. Mold for forming containers. An annular groove having a smooth concave curved surface is formed in the annular surface portion, and a gentle annular protrusion is formed on the end surface of the parison on the opening side of the flange-shaped mouth portion. Item 1. A mold for forming a resin container according to item 1. The first annular stepped portion is formed to be uniformly deeper than the second annular stepped portion, and by being formed deeper, the first annular step portion is formed deeper than the mouth compression cavity. The mold for molding a resin container according to claim 1 or 2, wherein the volume of the cavity is large. The first annular step has a recess formed in at least a part thereof compared to the second annular step, and the recess makes the mouth forming cavity smaller than the mouth compression cavity. The mold for molding a resin container according to claim 1 or 2, wherein the mold has a large volume. A plurality of radial grooves are formed in the first annular step, and a plurality of radial stripes are formed in the flange-like opening of the parison, and the stripes The mold for molding a resin container according to claim 1 or 2, wherein the volume of the mouth-forming cavity is larger than the mouth-compression cavity by an amount corresponding to the volume of the mouth-forming cavity. The width of the groove is narrower in the depth direction of the groove, and the cross section of the stripe of the parison is such that the width narrows in the height direction of the stripe. Mold for molding resin containers. 7. The mold for molding a resin container according to claim 6, wherein the groove has a triangular cross-sectional shape, and the striped protrusion of the parison has a triangular cross-section. The mold for molding a resin container according to claim 1 or 2, wherein the blow molding mold consists of two split molds. A group of injection molding molds,
A group of blow molding molds,
Consisting of a reversible intermediate mold group,
The injection mold group consists of a plurality of the injection molds,
The blow molding mold group consists of the same number of blow molding molds as the injection molding mold,
The intermediate mold group includes a first intermediate mold group and a second intermediate mold group that are arranged back to back, and the first intermediate mold group and the second intermediate mold group are Both are composed of the same number of intermediate molds as the injection molding molds,
When the intermediate mold group is placed in the first inverted position and the molds are clamped, the injection mold of the injection mold group and the intermediate mold of the first intermediate mold group are connected to each other. The intermediate mold of the second intermediate mold group and the blow molding mold group of the blow molding mold group are respectively clamped,
When the intermediate mold group is placed in the second inverted position and the molds are clamped, the injection mold of the injection mold group and the intermediate mold of the second intermediate mold group are connected to each other. The resin container according to claim 1 or 2, wherein the intermediate mold of the first intermediate mold group and the blow molding mold of the blow molding mold group are respectively clamped. Molding mold. mold clamping device;
an injection device that injects resin;
A mold installed in the mold clamping device,
a compressed air supply device that supplies compressed air to the mold,
The mold clamping device includes a fixed platen;
A movable platen that opens and closes the mold using a mold clamping mechanism;
an intermediate plate that is reversibly provided between the fixed plate and the movable plate,
The mold includes an injection mold group that is provided on the fixed plate and includes at least one injection mold;
a blow molding mold group provided on the movable platen and comprising the same number of blow molding molds as the injection molding mold;
a first intermediate mold group provided on one surface of the intermediate board and consisting of the same number of intermediate molds as the injection molding mold;
a second intermediate mold group, which is provided on the other surface of the intermediate board and includes the same number of intermediate molds as the injection molding mold;
The injection mold includes a first recess and a first annular step formed around the first recess,
The blow molding mold is composed of a plurality of split molds, and when combined, a second recess and a second annular step are formed.
The intermediate mold includes a core in which compressed air holes are formed and an annular surface portion that is an annular surface formed around the core,
When the intermediate disk is placed in a first inverted position and the mold clamping device is clamped, the injection mold of the injection mold group and the intermediate mold of the first intermediate mold group; and the intermediate mold of the second intermediate mold group and the blow molding mold of the blow molding mold group are respectively clamped,
When the intermediate disk is placed in a second inverted position and the mold clamping device is clamped, the injection mold of the injection mold group and the intermediate mold of the second intermediate mold group; and the intermediate mold of the first intermediate mold group and the blow molding mold of the blow molding mold group are respectively clamped,
When the injection mold and the intermediate mold are clamped, a main body forming cavity that forms the main body of the parison from the first recess and the core is connected to the first annular stepped portion. and the annular surface portion each form a mouth forming cavity that forms a flange-like mouth of the parison,
When the blow molding mold and the intermediate mold are clamped, a mouth compression cavity is configured to compress the flange-shaped mouth of the parison from the second annular step and the annular surface. It has come to be
The volume of the mouth forming cavity is larger than that of the mouth compression cavity,
The first annular step portion includes an outer circumferential surface forming side wall surface for forming an outer circumferential surface of the flange-shaped opening of the parison, and the outer circumferential surface forming side wall surface is connected to a parting line;
The second annular stepped portion includes an outer circumferential surface contacting side wall surface that contacts the outer circumferential surface of the flange-shaped opening of the parison, and the outer circumferential surface contacting side wall surface is connected to a parting line. Injection blow molding machine for container molding. An annular groove having a smooth concave curved surface is formed in the annular surface portion, and a gentle annular protrusion is formed on the end surface of the parison on the opening side of the flange-shaped mouth portion. Item 11. An injection blow molding machine for molding resin containers according to item 10. The first annular stepped portion is formed to be uniformly deeper than the second annular stepped portion, and by being formed deeper, the first annular step portion is formed deeper than the mouth compression cavity. The injection blow molding machine for molding a resin container according to claim 10 or 11, wherein the volume of the cavity is large. The first annular step has a recess formed in at least a part thereof compared to the second annular step, and the recess makes the mouth forming cavity smaller than the mouth compression cavity. The injection blow molding machine for molding a resin container according to claim 10 or 11, wherein the volume is increased. A plurality of radial grooves are formed in the first annular step, and a plurality of radial stripes are formed in the flange-like opening of the parison, and the stripes The injection blow molding machine for molding a resin container according to claim 10 or 11, wherein the volume of the mouth forming cavity is larger than the mouth compressing cavity by an amount equal to . 15. The width of the groove is narrower in the depth direction of the groove, and the cross section of the striation of the parison is such that the width narrows in the height direction of the striation. Injection blow molding machine for molding resin containers. 16. The injection blow molding machine for molding a resin container according to claim 15, wherein the groove has a triangular cross-sectional shape, and the striped protrusion of the parison has a triangular cross-section. 12. The injection blow molding machine for molding a resin container according to claim 10 or 11, wherein the blow molding mold consists of two split molds.

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