Blow molding apparatus and method for manufacturing a hollow body

Abstract

The present invention provides a blow molding apparatus that is lightweight by means of a clamping mechanism without a mounting plate. 【Solution means】The blow molding apparatus 1 includes a plurality of sets of molds 30 along the outer peripheral edge of a rotating disk 10 and a plurality of sets of opening and closing mechanisms 20 for opening and closing the plurality of sets of molds 30. The swing mechanism 23 includes a fixed disk 40, a swing disk 50, and an opening and closing rod 234. The swing disk 50 is fixed to the opening and closing rod 234 and is arranged so as to be able to open and close the second mold 32 with respect to the first mold 31 by axially rotating the opening and closing rod 234. The closed first mold 31 and second mold 32 form two annular inclined surfaces at positions facing the first block 212 and the second block 222. The first block 212 has a first inner peripheral surface that engages with one inclined surface. The second block 222 has a second inner peripheral surface that has the bottom mold 34 fixed thereto, is arranged so as to surround the bottom mold 34, and engages with the other inclined surface.

Description

Technical Field

[0001] The present invention relates to a blow molding apparatus and a method for manufacturing a hollow body.

Background Art

[0002] Conventionally, a blow molding apparatus having a plurality of sets of molds along the outer peripheral edge of a turntable includes a set of swing disks and a set of blow molding molds attached to each of the swing disks via mounting disks (Patent Document 1). In the opening / closing mechanism of the conventional blow molding apparatus, the swing disk is generally not fixed to the opening / closing center shaft but is merely rotatably supported by the opening / closing center shaft.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a blow molding apparatus such as that of Patent Document 1, since a rotating shaft, a connecting arm, etc. for opening and closing the blow molding mold are required further outside the opening / closing center shaft, it is difficult to miniaturize the opening / closing mechanism. Further, in a blow molding apparatus such as that of Patent Document 1, a mounting disk is required between the blow molding mold and the swing disk to generate a clamping force, and the opening / closing mechanism becomes heavy.

[0005] Therefore, an object of the present invention is to provide a blow molding apparatus in which the opening / closing mechanism is miniaturized and lightened. Another object of the present invention is to provide a method for manufacturing a hollow body capable of improving productivity.

Means for Solving the Problems

[0006] The present invention has been made to solve at least a part of the above-described problems and can be realized as the following aspects or application examples.

[0007] [1] One aspect of the blow molding apparatus according to the present invention is a blow molding apparatus including a plurality of sets of molds along an outer peripheral edge of a turntable and a plurality of sets of opening and closing mechanisms for opening and closing the plurality of sets of molds, each of the plurality of sets of molds including a first mold and a second mold that form a body portion of a hollow body and a bottom mold that forms a bottom portion of the hollow body, each of the plurality of sets of opening and closing mechanisms including a swing mechanism, a first mold clamping mechanism, and a second mold clamping mechanism provided on the turntable, the swing mechanism including a fixed plate to which the first mold is fixed, a swing plate to which the second mold is fixed, and an opening and closing rod rotatably supported by the turntable, the fixed plate being supported by the opening and closing rod and fixed to the turntable, the swing plate being fixed to the opening and closing rod and installed so as to be openable and closable with respect to the first mold by rotating the opening and closing rod about an axis, the first mold clamping mechanism including a first block that can advance and retreat with respect to the closed first mold and second mold, the second mold clamping mechanism including a second block that can advance and retreat with respect to the closed first mold and second mold at a position facing the first block with the first mold and second mold interposed therebetween, the closed first mold and second mold form two annular inclined surfaces at positions facing the first block and the second block, the first block having a first inner peripheral surface that engages with one of the inclined surfaces, the second block being characterized in that the bottom mold is fixed thereto, is disposed so as to surround the bottom mold, and has a second inner peripheral surface that engages with the other inclined surface.

[0008] [2] In the blow molding apparatus according to the above aspect, The fixed plate and the swing plate each have a flow path through which a heat medium flows inside. The first type is heated or cooled by directly contacting the fixed plate. The second type can be heated or cooled by directly contacting the swing plate.

[0009] [3] In the blow molding apparatus according to any one of the above aspects, The swing mechanism further includes a guide portion provided along the rotating disk and a guided portion fixed to the opening / closing rod. The opening / closing rod can rotate about its axis when the rotating disk rotates and the guided portion is guided by the guide portion.

[0010] [4] One aspect of the method for manufacturing a hollow body according to the present invention is A method for manufacturing the hollow body using one aspect of the blow molding apparatus, With the mold carried by the rotating disk open, place the preform at a predetermined position of the first mold. Rotate the opening / closing rod about its axis to swing the swing plate toward the fixed plate to close the second mold and the first mold. Engage the first block and the second block with the first mold and the second mold that are closed. Blow mold the preform into the hollow body in the cavity formed by the first mold, the second mold, and the bottom mold. Characterized by rotating the opening / closing rod about its axis to separate the swing plate from the fixed plate and taking out the hollow body from the first mold.

Advantages of the Invention

[0011] According to the blow molding apparatus of the present invention, since the swing plate is fixed to the opening and closing rod, and the first mold and the second mold are directly fixed to the fixed plate and the swing plate without passing through the mounting plate, respectively, a blow molding apparatus with a downsized and lightweight clamping mechanism can be provided. According to the method for manufacturing a hollow body of the present invention, since a hollow body is manufactured using a blow molding apparatus with a downsized and lightweight opening and closing mechanism, the operating speed can be increased and the productivity can be improved.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0013] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention described in the claims. Also, not all of the configurations described below are essential constituent elements of the present invention.

[0014] 1. Blow Molding Apparatus The blow molding apparatus 1 according to the present embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic plan view of the blow molding apparatus 1 according to the present embodiment.

[0015] As shown in FIG. 1, the blow molding apparatus 1 includes, for example, a heating unit 4, a first transfer unit 5, a blow molding unit 6, and a second transfer unit 7 disposed on a base 2. The blow molding unit 6 of the blow molding apparatus 1 includes a plurality of sets of molds 30 along the outer peripheral edge of a turntable 10 and a plurality of sets of opening and closing mechanisms 20 for opening and closing the plurality of sets of molds 30. The blow molding apparatus 1 can further include a feeder 3 and a discharge unit 8.

[0016] The base 2 is, for example, in the form of a housing or a frame. The base 2 is installed on the floor of a hollow body manufacturing factory. Components of each part including the heating unit 4 and the blow molding unit 6 are arranged on the base 2.

[0017] The feeder 3 supplies the preform 62 to the heating unit 4. The feeder 3 is disposed on the base 2 adjacent to the heating unit 4. The feeder 3 can employ a known mechanism. The preform 62 includes, for example, an opening mouth part, a substantially cylindrical body part connected to the mouth part, and a bottom part closing the body part. The preform 62 is made of synthetic resin and is generally manufactured by injection molding, but those manufactured by extrusion molding or compression molding may also be used. The feeder 3 includes, for example, a hopper, an inclined conveyor, an aligner, and a chute disposed on the side of the base 2. The feeder 3 sequentially supplies the preform 62 to the heating unit 4 while supporting and suspending the aligned preforms 62 in a state where the mouth parts are downward. The blow molding apparatus 1 may include a supply wheel for delivering the preform 62 from the feeder 3 to the heating unit 4. The supply wheel can use, for example, the mechanism disclosed in Japanese Patent Application Laid-Open No. 2012-229114. The supply wheel may further include a mechanism for inverting the preform 62 to an inverted state with the mouth part downward.

[0018] The heating unit 4 includes a conveyance path for conveying the preform 62 and a plurality of heaters arranged along the conveyance path. As the heating unit 4, a known mechanism can be adopted. The conveyance path is, for example, an oval circulation path, and preform carriers (not shown) are arranged along the conveyance path at regular intervals. The preform carrier holds, for example, the mouth portion of the preform 62 received from the feeder 3 and conveys the preform 62 along the conveyance path. The heating unit 4 heats the preform 62 to a temperature suitable for blow molding with heaters while moving the preform along the conveyance path.

[0019] The first transfer unit 5 receives the heated preform 62 from the conveyance path of the heating unit 4 and sequentially delivers it to the blow molding unit 6. The first transfer unit 5 is located on the base 2 and is arranged between the heating unit 4 and the blow molding unit 6. As the first transfer unit 5, a known mechanism can be adopted. For example, the first transfer unit 5 can use the mechanism disclosed in Japanese Patent Application Laid-Open No. 2004-155147. It may further include a mechanism for inverting, for example, in an inverted state with the mouth portion facing down, according to the configuration of the blow molding unit 6.

[0020] The blow molding unit 6, although details will be described later, has a plurality of sets of opening and closing mechanisms 20 mounted on the rotating disk 10 at predetermined intervals. The blow molding unit 6 is arranged on the base 2 adjacent to the heating unit 4 with the first transfer unit 5 interposed therebetween. The rotating disk 10 is, for example, substantially annular in plan view (FIG. 1) and substantially flat plate-shaped in side view (FIG. 2). The rotating disk 10 rotates continuously at a predetermined speed. A set of molds 30 is attached to each opening and closing mechanism 20. Due to the rotation of the rotating disk 10, the molds 30 attached to each opening and closing mechanism 20 circulate along a circular circulation path. The molds 30 are opened by the opening and closing mechanism 20 at a predetermined position on the circular circulation path and closed at another predetermined position on the circular circulation path. The preform 62 received from the first transfer unit 5 is fed into the molds 30 and blow molded while being conveyed along the circular circulation path to be formed into a predetermined hollow body. The hollow body formed by the blow molding unit 6 is in an upright state with the opening facing upward. In this embodiment, an example where the hollow body 60 is in an upright state will be described, but the molds 30 may be turned upside down to form the hollow body in an inverted state with the opening facing downward.

[0021] The second transfer unit 7 receives the hollow body 60 from the blow molding unit 6 and sequentially transfers it to the discharge unit 8. The second transfer unit 7 is located on the base 2 and is disposed between the blow molding unit 6 and the discharge unit 8. The second transfer unit 7 can adopt a known mechanism, for example, a mechanism in which a plurality of arms respectively hold the hollow body 60. The opening and closing mechanism 20 opens the mold in front of the second transfer unit 7 and closes the mold after passing the first transfer unit 5. When the blow molding unit 6 molds the hollow body 60 in an inverted state, the second transfer unit 7 may be provided with a mechanism for inverting the hollow body 60 to an upright state.

[0022] The discharge unit 8 receives the hollow body 60 from the second transfer unit 7 and moves the hollow body 60 outside the blow molding apparatus 1. The discharge unit 8 is disposed adjacent to the blow molding unit 6 with the second transfer unit 7 interposed therebetween. The discharge unit 8 can adopt a known mechanism, for example, a continuously operating belt conveyor. The hollow body 60 sent out from the discharge unit 8 to the outside of the blow molding apparatus 1 is transferred to a subsequent process (not shown), for example, a packing process or a filling process.

[0023] 2. Blow molding unit The blow molding unit 6 of the blow molding apparatus 1 according to the present embodiment will be described with reference to FIGS. 2 to 6. FIG. 2 is a perspective view showing an enlarged part of the blow molding unit 6, FIG. 3 is a perspective view of the blow molding unit 6 in a mold-closed state, FIG. 4 is a perspective view of the blow molding unit 6 in a mold-open state, FIG. 5 is a cross-sectional view taken along line A-A in FIG. 3 of the blow molding unit 6 in a mold-closed state, and FIG. 6 is a cross-sectional view taken along line B-B in FIG. 3 of the blow molding unit 6 in a mold-clamped state. Note that the bottom mold 34 is not closed in FIGS. 3 and 4.

[0024] FIG. 2 shows an enlarged view of the turntable 10, a set of molds 30, and a set of opening / closing mechanisms 20 of the blow molding section 6, with adjacent molds 30 and opening / closing mechanisms 20 shown omitted. In FIG. 2, the mold 30 shows the mold-open state. The mold-open state is the state before receiving a preform (not shown) into the mold 30 or after taking out a hollow body (not shown) from outside the mold 30. FIGS. 3 and 4 show an omission of the turntable 10 to clearly show the positional relationship of the components above and below the turntable 10. Further, FIG. 5 shows a state where the preform 62 is disposed in the mold 30, and FIG. 6 shows a state where the hollow body 60 is formed in the mold 30.

[0025] A plurality of through holes penetrating vertically are formed in the turntable 10 in accordance with the positions of the opening / closing mechanisms 20. On the upper surface of the turntable 10, first columns 11 extending upward from the upper surface are fixed at positions where all the opening / closing mechanisms 20 are installed. On the lower surface of the turntable 10, second columns 12 extending downward from the lower surface are fixed at positions where all the opening / closing mechanisms 20 are installed. The opening / closing rod 234 is rotatably disposed through the through hole formed in the turntable 10 vertically.

[0026] Each of the plurality of sets of molds 30 includes a first mold 31 and a second mold 32 that form the body portion of the hollow body 60 (see FIG. 4), and a bottom mold 34 that forms the bottom of the hollow body 60. The first mold 31 and the second mold 32 are configured such that an opening is formed at the upper end in the mold-closed state. For example, the preform 62 and, for example, the vicinity of the mouth portion (opening portion) of the hollow body 60 can be held in the opening. The first mold 31 and the second mold 32 are configured such that an opening is formed at the lower end in the mold-closed state. The opening can receive the bottom mold 34. The mold 30 may further include an extension rod 33 extending in the vertical direction. The extension rod 33 is inserted into the mouth portion of the preform 62 held in the mold 30 in the mold-closed state from above.

[0027] Each of the plurality of sets of opening / closing mechanisms 20 includes a swing mechanism 23, a first mold clamping mechanism 21, and a second mold clamping mechanism 22 provided at a predetermined position of the turntable 10. The first mold clamping mechanism 21 is the turntable Above 10 and provided on the first support column 11. The second clamping mechanism 22 is below the rotating disk 10 and provided on the second support column 12. The swing mechanism 23 is provided across the upper and lower sides of the rotating disk 10 with the rotating disk 10 in between.

[0028] The swing mechanism 23 includes a fixed disk 40 to which the first mold 31 is fixed, a swing disk 50 to which the second mold 32 is fixed, and an opening and closing rod 234 rotatably supported by the rotating disk 10.

[0029] The fixed disk 40 is supported by the opening and closing rod 234 and fixed to the rotating disk 10. By the fixed disk 40 being supported by the opening and closing rod 234, the position of the fixed disk 40 can be accurately set with respect to the swing disk 50 that swings with the opening and closing rod 234. The lower end of the fixed disk 40 is fixed to the upper surface of the rotating disk 10. The fixed disk 40 has a structure that covers substantially the entire side surface of the first mold 31 except for the side surface where the cavity of the first mold 31 is formed. With this structure, the fixed disk 40 is in direct contact with the side surface of the first mold 31.

[0030] The fixed disk 40 includes two support portions 41a and 41b that extend toward the first support column 11 beyond the opening and closing rod 234. The support portion 41a extends laterally from near the upper end of the fixed disk 40 and is fixed to the side surface of the first support column 11. The support portion 41b extends laterally from near the lower end of the fixed disk 40 and is fixed to the side surface of the first support column 11. As shown in FIG. 6, the opening and closing rod 234 extends so as to penetrate the support portions 41a and 41b vertically. Bearings 42a and 42b are provided between the support portions 41a and 41b and the opening and closing rod 234, and the opening and closing rod 234 is rotatable with respect to the support portions 41a and 41b.

[0031] The swing plate 50 is fixed to the opening / closing rod 234 and is arranged to be openable / closable with respect to the first mold 31 by rotating the opening / closing rod 234 about its axis. The swing plate 50 includes a fixing portion 51 that extends from the side of the swing plate 50 toward the opening / closing rod 234. The fixing portion 51 is substantially cylindrical and is fixed integrally with the opening / closing rod 234. The fixing portion 51 is between the upper and lower support portions 41a and 41b. For the fixing of the fixing portion 51 and the opening / closing rod 234, for example, a friction fastener or the like can be employed. The second mold 32 is fixed to the surface of the swing plate 50 on the side of the fixed plate 40. The swing plate 50 has a structure that covers substantially the entire side surface of the second mold 32 except for the side surface where the cavity of the second mold 32 is formed. With this structure, the swing plate 50 is in direct contact with the side surface of the second mold 32.

[0032] The opening / closing rod 234 extends through the rotating plate 10 in the vertical direction. The opening / closing rod 234 above the rotating plate 10 extends to a position higher than the fixed plate 40 and the swing plate 50. A nut is fastened to the portion protruding above the support portion 41a at the upper end of the opening / closing rod 234 to limit downward movement. The opening / closing rod 234 below the rotating plate 10 is restricted from moving upward at the stepped portion of the opening / closing rod 234.

[0033] The opening / closing rod 234 is rotatably supported by the rotating plate 10 via a bearing 13. The central axis of the opening / closing rod 234 extends in the vertical direction with respect to the rotating plate 10, and the opening / closing rod 234 rotates about this central axis. The central axis of the opening / closing rod 234 is provided adjacent to the second mold 32. The central axis of the opening / closing rod 234 may be parallel to the central axis (the central axis of the opening) of the cavity of the hollow body 60 formed by the first mold 31 and the second mold 32 in the closed state.

[0034] The swing mechanism 23 can further include a guide portion 233 provided along the rotating disk 10 and a guided portion 232 fixed to the opening and closing rod 234. The guide portion 233 is provided below the rotating disk 10. An opening and closing arm 230 extending horizontally from the lower end of the opening and closing rod 234 is fixed to the opening and closing rod 234. The guided portion 232 is fixed to the tip of the opening and closing arm 230. The guided portion 232 is, for example, a cam follower. The guide portion 233 is, for example, a guide surface on which the cam follower rolls while in contact. The opening and closing rod 234 rotates about its axis as the rotating disk 10 rotates and the guided portion 232 is guided by the guide portion 233.

[0035] In the conventional blow molding section, both the left and right blow molds were opened and closed together. However, in this embodiment, only the swing disk 50 and the second mold 32 need to be opened and closed. Therefore, it is possible to increase the speed by reducing the weight, and an improvement in productivity can be expected. Further, since the swing mechanism 23 does not have a lock mechanism after mold closing as in the prior art, there is no need to bear the mold clamping force. As a result, the swing disk 50 can be reduced in weight. Since the members that perform the opening and closing operation are reduced in weight, the swing disk 50 can be directly swung with the opening and closing rod 234 as the rotation axis, which simplifies the structure compared to the prior art and further reduces the weight of the swing mechanism 23. Further, according to the swing mechanism 23, since the first mold 31 does not perform the mold opening operation, the second mold 32, the first block 212, and the second block 222 can be reliably positioned in accordance with the first mold 31.

[0036] The fixed plate 40 and the swing plate 50 each include, for example, a flow path 36 through which a heat medium flows inside. The flow path 36 may be, for example, an electric heater other than the flow path 36, or may be other heat exchangers. There is no mounting plate as in the prior art between the fixed plate 40 and the side surface of the first mold 31. Also, there is no mounting plate as in the prior art between the swing plate 50 and the side surface of the second mold 32. Therefore, the first mold 31 is heated or cooled by directly contacting the fixed plate 40, and the second mold 32 is heated or cooled by directly contacting the swing plate 50. That is, the fixed plate 40 and the swing plate 50 are heat exchange parts of the first mold 31 and the second mold 32. Since there is no mounting plate as in the prior art, the temperature of the mold 30 can be adjusted to an appropriate temperature by the flow path 36. Also, since there is no mounting plate as in the prior art, the fixed plate 40 and the swing plate 50 can be miniaturized and lightened. Due to this miniaturization, the distance between adjacent opening and closing mechanisms 20 can be narrowed, so the number of molds 30 that can be installed on the rotating plate 10 can be increased.

[0037] The first mold 31 includes a first outer peripheral surface 311 at the upper end, one cavity on the side surface not facing the swing plate 50, and a second outer peripheral surface 312 at the lower end. The second mold 32 includes a first outer peripheral surface 321 at the upper end, the other cavity on the side surface not facing the swing plate 50, and a second outer peripheral surface 322 at the lower end. The first outer peripheral surfaces 311 and 321 are each substantially arc-shaped in plan view and are inclined surfaces that taper upward in side view. The second outer peripheral surfaces 312 and 322 are each substantially arc-shaped in plan view and are inclined surfaces that taper downward in side view.

[0038] When the first mold 31 and the second mold 32 are closed, two annular inclined surfaces are formed at positions facing the first block 212 and the second block 222. The annular inclined surface formed at the upper end of the mold 30 is a substantially frustum-shaped outer peripheral surface composed of the first outer peripheral surfaces 311 and 321. An opening for receiving the preform 62 is formed at the center of the annular inclined surface. The annular inclined surface formed at the lower end of the mold 30 is a substantially frustum-shaped outer peripheral surface composed of the second outer peripheral surfaces 312 and 322. An opening for receiving the bottom mold 34 is formed at the center of the annular inclined surface.

[0039] The first clamping mechanism 21 includes a first driving part 210 and a first block 212. The first driving part 210 is fixed to the first support column 11. The first driving part 210 can move the first block 212 up and down with respect to the upper end of the mold 30. The first block 212 can move forward and backward with respect to the first mold 31 and the second mold 32 that are closed. The first block 212 has a through hole for inserting the rod 33 at the center and a recess that opens downward. A seal member 214 is provided at a portion that abuts against the preform 62 of the recess. The first block 212 has a first inner peripheral surface 213 that engages with an annular inclined surface formed at the upper end of the mold 30, which is one of the inclined surfaces. The first inner peripheral surface 213 is the inner peripheral surface of a recess provided on the lower surface of the first block 212. The first inner peripheral surface 213 expands in diameter downward. By engaging the annular inclined surface at the upper end of the mold 30 with the first inner peripheral surface 213, the movement of the second mold 32 away from the first mold 31 is prevented. In particular, when high-pressure air is blown in during blow molding, a force that presses the first outer peripheral surface 311 and the second outer peripheral surface 312 against the first inner peripheral surface 213 acts to resist the force that opens the mold 30 and suppress the upward movement of the first block 212, thereby maintaining airtightness.

[0040] The second clamping mechanism 22 includes a second driving part 220 and a second block 222. The second driving part 220 is attached to the second support column 12. The second driving part 220 can move the second block 222 up and down with respect to the lower end of the mold 30. The second driving part 220 may further include a guide rail fixed to the side surface of the second support column 12, a linear guide guided along the guide rail, a cam follower integrated with the linear guide and the second driving part 220, and a guide surface for guiding the cam follower. By guiding the cam follower on the guide surface provided below the turntable 10 and moving the second driving part 220 and the second block 222 up and down, the lifting stroke of the second driving part 220 can be shortened.

[0041] In this embodiment, the first drive unit 210 and the second drive unit 220 employ air cylinders. However, as long as the first block 212 and the second block 222 can be moved up and down, other known drive mechanisms such as cam mechanisms, link mechanisms, electric motors, hydraulic cylinders, etc. may be employed.

[0042] The second block 222 is disposed at a position facing the first block 212 with the first mold 31 and the second mold 32 interposed therebetween. The second block 222 is capable of moving forward and backward with respect to the first mold 31 and the second mold 32 with the mold closed. The second block 222 has a second inner peripheral surface 223 to which the bottom mold 34 is fixed and which is disposed so as to surround the bottom mold 34 and engages with the lower end of the mold 30, which is the other inclined surface. The second inner peripheral surface 223 is the inner peripheral surface of a recess provided on the upper surface of the second block 222. The second inner peripheral surface 223 has a diameter that increases upward. The second block 222 and the bottom mold 34 are integral. The engagement of the annular inclined surface at the lower end of the mold 30 with the second inner peripheral surface 223 prevents the first mold 31 and the second mold 32 from moving away from each other. Further, when high-pressure air is blown in during blow molding, a force that presses the first outer peripheral surface 321 and the second outer peripheral surface 322 against the second inner peripheral surface 223 acts to resist the force that opens the mold 30 and suppress the downward movement of the second block 222.

[0043] The swing mechanism 23 can improve the production capacity of the blow molding apparatus 1 by being made smaller and lighter and thus operating at higher speeds. Further, due to the miniaturization of the swing mechanism 23, the number of molds 30 that can be installed can be increased, so that the production capacity of the blow molding apparatus 1 can be improved even if the installation area is the same.

[0044] 3. Manufacturing method of a hollow body Using FIGS. 1 to 6, the manufacturing method of the hollow body 60 according to this embodiment will be described. The manufacturing method of the hollow body 60 according to this embodiment is a method of manufacturing the hollow body 60 using the blow molding apparatus 1.

[0045] The manufacturing method of the hollow body 60 includes a placing step, a mold closing step, an engaging step, a blow molding step, and a taking-out step. The manufacturing method of the hollow body can further include a supplying step and a heating step before the placing step.

[0046] The supplying step is a step in which the preform 62 is sequentially supplied by the feeder 3 to the heating unit 4.

[0047] The heating step is a step in which the preform 62 is heated to a predetermined temperature in the heating unit 4.

[0048] The placing step is a step in which the preform 62 is placed at a predetermined position in the first mold 31 with the mold 30 carried by the turntable 10 in an open state. In the placing step, for example, the first transfer unit 5 places the preform 62 heated to a predetermined temperature at a predetermined position in the first mold 31.

[0049] The mold closing step is a step in which the swing plate 50 is swung toward the fixed plate 40 by rotating the opening and closing rod 234 about its axis to close the second mold 32 and the first mold 31. In the mold closing step, as the turntable 10 rotates, the guided portion 232 contacts the guide portion 23 provided below the turntable 10, and the opening and closing arm 230 is pivoted to rotate the opening and closing rod 234 about its axis. When the opening and closing rod 234 rotates about its axis, the swing plate 50 integral with the opening and closing rod 234 swings toward the fixed plate 40 and moves at high speed until the second mold 32 contacts the first mold 31. When the opening and closing rod 234 rotates about its axis, the swing plate 50 integral with the opening and closing rod 234 swings toward the fixed plate 40 and moves at high speed until the second mold 32 contacts the first mold 31.

[0050] The engaging step is a step of engaging the first block 212 and the second block 222 with the closed first mold 31 and second mold 32, and blow molding the preform 62 into the hollow body 60 in the cavity formed by the first mold 31, the second mold 32, and the bottom mold 34. At the upper end of the mold 30 in the closed state, a conical inclined surface is formed by the first outer peripheral surfaces 311 and 321 as shown in FIG. 3. Similarly, at the lower end of the mold 30 in the closed state, a conical inclined surface is formed by the second outer peripheral surfaces 312 and 322. These inclined surfaces and the first inner peripheral surface 213 of the first block 212 and the second inner peripheral surface 223 of the second block 222 have the same inclination angle. Therefore, when the inner peripheral surface contacts the inclined surface, a clamping force is generated vertically with respect to the first mold 31 and the second mold 32 to prevent mold opening. The opening and closing rod 234 does not need to bear the clamping force. Also, by raising the second block 222, the bottom mold 34 is inserted from the lower ends of the closed first mold 31 and second mold 32. Then, the extension rod 33 is inserted into the preform 62 from the mouth portion and descends, and high-pressure air is introduced to form the hollow body 60. Before and during blow molding, the first inner peripheral surface 213 is pressed against the conical inclined surface of the frustum by the first outer peripheral surfaces 311 and 321, and the second inner peripheral surface 223 is pressed against the conical inclined surface of the frustum by the second outer peripheral surfaces 312 and 322, thereby preventing the first mold 31 and the second mold 32 from opening and restricting the movement of the first block 212 and the second block 222. As a result, the contact between the seal member 214 of the first block 212 and the mouth portion of the hollow body 60 is maintained and air sealing can be achieved.

[0051] The taking-out step is a step of rotating the opening / closing rod 234 about its axis to separate the swing plate 50 from the fixed plate 40 and taking out the hollow body 60 from the first mold 31. By raising the first block 212 and the extension rod 33 and lowering the second block 222 and the bottom mold 34, the clamping state between the first mold 31 and the second mold 32 can be released. When the swing plate 50 swings, the hollow body 60 is released from the second mold 32. On the other hand, since the fixed plate 40 is at a fixed position with respect to the rotating plate 10, the second transfer unit 7 only needs to take out the hollow body 60 from the first mold 31. The second transfer unit 7 holding the hollow body 60 delivers the hollow body 60 to the discharge unit 8. The discharge unit 8 sequentially discharges the formed hollow body 60 out of the blow molding apparatus 1.

[0052] According to the method for manufacturing the hollow body 60 according to the present embodiment, high-speed production is possible as compared with the conventional method, and the productivity with respect to the installation area of the blow molding apparatus 1 is improved.

[0053] The present invention is not limited to the above-described embodiments, and various modifications are further possible. The present invention includes configurations that are substantially the same as the configurations described in the embodiments (configurations having the same functions, methods, and results, or configurations having the same objectives and effects). Further, the present invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Further, the present invention includes configurations having the same operational effects as the configurations described in the embodiments or configurations capable of achieving the same objectives. Further, the present invention includes configurations in which known technologies are added to the configurations described in the embodiments.

Explanation of Reference Numerals

[0054] 1... Blow molding device, 2... Base, 3... Feeder, 4... Heating section, 5... First transfer section, 6... Blow molding section, 7... Second transfer section, 8... Discharge section, 10... Rotary disk, 11... First support column, 12... Second support column, 13... Bearing, 20... Opening and closing mechanism, 21... First mold clamping mechanism, 210... First drive section, 212... First block, 213... First inner peripheral surface, 214... Seal member, 22... Second mold clamping mechanism, 220... Second drive section, 222... Second block, 223... Second inner peripheral surface, 23... Oscillation mechanism, 230... Opening and closing arm, 232... Guided part, 233... Guide part, 234... Opening and closing rod, 30... Mold, 31... First mold, 311... First outer peripheral surface, 312... Second outer peripheral surface, 32... Second mold, 32 1... First outer peripheral surface, 322... Second outer peripheral surface, 33... Extension rod, 34... Bottom mold, 36... Flow path, 40... Fixed disk, 41a, 41b... Support parts, 42a, 42b... Bearings, 50... Oscillation disk, 51... Fixed part, 60... Hollow body, 62... Preform

Claims

1. A blow molding apparatus comprising a plurality of sets of molds arranged along an outer periphery of a rotating platen, and a plurality of opening / closing mechanisms for opening and closing the plurality of sets of molds, Each of the plurality of sets of molds includes a first mold and a second mold for forming a body portion of a hollow body, and a bottom mold for forming a bottom portion of the hollow body; Each of the plurality of sets of opening and closing mechanisms includes a swing mechanism, a first mold clamping mechanism, and a second mold clamping mechanism, which are provided on the rotary table; the rocking mechanism includes a fixed platen to which the first mold is fixed, a rocking platen to which the second mold is fixed, and an opening / closing rod rotatably supported by the rotating platen, The fixed platen is supported by the opening / closing rod and fixed to the rotating platen, the rocking plate is fixed to the opening / closing rod and is installed so as to be capable of opening and closing the second mold relative to the first mold by rotating the opening / closing rod around an axis; the first mold clamping mechanism includes a first block that is movable toward and away from the first mold and the second mold that are closed, the second mold clamping mechanism includes a second block that is located opposite to the first block with the first mold and the second mold interposed therebetween and is movable toward and away from the first mold and the second mold that are closed; The first and second dies, which are closed, form two annular inclined surfaces at positions facing the first and second blocks, the first block has a first inner circumferential surface that engages with one of the inclined surfaces, The second block has a second inner peripheral surface to which the bottom mold is fixed and which is disposed so as to surround the bottom mold and engages with the other inclined surface.

2. 2. The blow molding apparatus according to claim 1, The fixed platen and the oscillating platen each have a flow path therein through which a heat medium flows, the first mold is heated or cooled by direct contact with the stationary platen; A blow molding apparatus, wherein the second mold is heated or cooled by direct contact with the rocking platen.

3. The blow molding apparatus according to claim 1 or 2, the swing mechanism further includes a guide portion provided along the rotary disk and a guided portion fixed to the opening / closing rod, The blow molding apparatus, characterized in that the opening and closing rod rotates on its axis as the rotary plate rotates and the guided portion is guided by the guide portion.

4. A method for producing the hollow body using the blow molding apparatus according to claim 1, comprising the steps of: A preform is placed in a predetermined position in the first mold while the mold carried by the rotating platen is open; The opening / closing rod is rotated about an axis to swing the swing platen toward the fixed platen, thereby closing the second mold and the first mold; Engaging the first block and the second block with the first die and the second die which are closed, Blow-molding the preform into the hollow body in a cavity formed by the first mold, the second mold, and the bottom mold; A method for manufacturing a hollow body, comprising rotating the opening / closing rod around its axis to move the rocking platen away from the fixed platen, thereby removing the hollow body from the first mold.

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