JP4559164B2 - Preform heating device - Google Patents

Description

  The present invention relates to a preform heating apparatus.

  As synthetic resin bottles, containers made of polyethylene terephthalate, so-called PET bottles, are widely used.

  Such a PET bottle can be obtained by heating an injection-molded preform to a temperature suitable for blow molding or higher and performing stretch blow molding. In order to mold such a PET bottle, there is a blow molding apparatus. As a blow molding apparatus, there is known one in which a conveyance path for conveying a preform is arranged in each of a heating station and a blow molding station, and a transfer unit for transferring the preform is provided between these two conveyance paths. (For example, refer to Patent Document 1).

  There is also a preform heating device having a shutter member that shields the neck of the preform from the heat of the heat source of the heating unit (see, for example, Patent Document 2). In such a preform heating apparatus, a shutter member is provided on the opposite side of the preform with respect to the infrared heater as a heat source, and is moved forward and backward by the advance / retreat driving means.

However, since such a shutter member advances and retreats with respect to the preform from the side opposite to the infrared heater across the preform conveyance path, a cutout portion for receiving the preform must open on the infrared heater side. First, light from the infrared heater leaked from the opening to the neck portion side. In addition, the movement distance for moving the shutter member forward and backward from one side with respect to the preform conveyance direction becomes long. Therefore, when the preform stop period after intermittent conveyance is constant, the time for blocking the neck portion from the light of the infrared heater is long. It was relatively short.
WO98 / 09795 JP 2000-62011 A

  An object of the present invention is to provide a preform heating apparatus that efficiently protects a neck portion of a preform from a heat source.

The preform heating apparatus according to the present invention includes:
A conveyance path for intermittently conveying the preform;
A heating unit that is disposed along the conveyance path and heats the preform;
In a preform heating apparatus having
The preform has a neck portion, a cylindrical trunk portion connected to the neck portion, and a bottom portion that closes the trunk portion,
The heating unit is
A heat source for heating the barrel,
A transport path for transporting the preform in series facing the heat source;
A first shutter member and a second shutter member that block heat from the heat source with respect to the neck portion;
A shutter drive mechanism for moving the first shutter member and the second shutter member toward and away from the preform stopped in the transport path;
Have
At least one of the first shutter member and the second shutter member has a cutout portion having a size for receiving the preform stopped in the transport path,
The first shutter member is disposed to face the second shutter member with the conveyance path interposed therebetween.

  According to one aspect of the present invention, since the shutter members are arranged on both sides of the preform, the distance and time for moving the shutter member toward and away from the preform can be shortened, and the neck portion can be effectively removed from the heat of the heat source. Can be protected.

In the preform heating apparatus according to the present invention,
The shutter drive mechanism is
A first rotating shaft provided on the first shutter member;
A second rotating shaft provided on the second shutter member;
And rotating means for rotating the first rotating shaft and the second rotating shaft.

  By adopting such a configuration, it is more compact than a conventional slide type advance / retreat drive mechanism. Therefore, for example, in the case of a structure in which the conveyance path conveys a plurality of rows of preforms, it can be arranged without interfering with the shutter members in the adjacent rows.

In the preform heating apparatus according to the present invention,
The heating unit simultaneously heats N preforms conveyed in series,
At least one of the first shutter member and the second shutter member may have N cutout portions that receive the N preforms stopped at a position facing the heat source.

  With such a configuration, even when the shutter member is configured to rotate, the neck portions of the N preforms facing the heat source in the heating unit can be simultaneously protected with a short rotational movement distance.

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

  FIG. 1 is a plan view showing an overall configuration of a blow molding apparatus according to an embodiment of the present invention. FIG. 2 is a side view of the heating unit according to the embodiment of the present invention. FIG. 3 is a front view of the shutter driving mechanism according to the embodiment of the present invention. 4 is a cross-sectional view taken along the line X-X ′ of FIG. 2 of the heating box according to the embodiment of the present invention. FIG. 5 is a plan view of the shutter member according to the embodiment of the present invention.

(Outline of blow molding equipment)
First, the outline | summary of the blow molding apparatus concerning one embodiment of this invention is demonstrated using FIG. In the blow molding apparatus 100, a heating station 112, a transfer unit 114, and a blow molding station 116 are linearly arranged on the machine base 450 along the conveying direction A of the preform 118. Furthermore, the heating station 112 includes a supply unit 110 and a first conveyance path 200 arranged along the preform conveyance direction A. The heating unit 112 includes the heating unit 111 on the first conveyance path 200. ing. The blow molding station 116 includes a receiving unit 402, a blow molding unit 404, and a take-out unit 406 on a substantially rectangular second conveyance path 400. Therefore, the preform 118 supplied to the blow molding apparatus 100 is conveyed from the supply unit 110 to the first conveyance path 200 of the heating station 112 in an inverted state, and is heated by the heating unit 111 to a temperature equal to or higher than the blow molding suitable temperature, and then transferred. It is transferred to the second conveyance path 400 (receiving unit 402) of the blow molding station 116 by the unit 114, blow-molded into the container 428 by the blow molding unit 404, and discharged out of the blow molding apparatus 100 from the take-out unit 406.

  Further, the preform 118 used in the present embodiment is a bottomed cylindrical molded product formed by, for example, injection molding, and as shown in FIG. 2, a neck portion 120 including an opening, and a cylindrical shape Body portion 121 and a bottom portion 122 that closes the body portion 121. In the blow molding unit 404 of the blow molding station 116, the body 121 and the bottom 122 of the preform 118 are blow-molded, so that a thin container 428 (for example, a PET bottle) can be molded. .

(Preform heating device)
A preform heating apparatus 300 according to an embodiment of the present invention is a heating station 112 of a blow molding apparatus 100.

  The heating station 112 includes a first conveyance path 200 that intermittently conveys the preform 118, and a heating unit 111 that is disposed along the first conveyance path 200 and heats the preform 118. The neck portion 120, a cylindrical trunk portion 121 that continues to the neck portion 120, and a bottom portion 122 that closes the trunk portion 121, and the heating unit 111 includes a heat source for heating the trunk portion 121, A conveyance path 201 that conveys the preform 118 in series facing the heat source, a first shutter member 306 and a second shutter member 308 that block heat from the heat source to the neck portion 120, and a first shutter member 306. And a shutter drive mechanism 340 for moving the second shutter member 308 closer to and away from the preform 118 stopped on the conveyance path 201, and At least one of the first shutter member 306 and the second shutter member 308 has a cutout portion 314 having a size for receiving the preform 118 stopped on the conveyance path 201, and the first shutter member 306 is conveyed. It is arranged to face the second shutter member 308 across the path 201.

  The heating station 112 includes a first conveyance path 200 that conveys, for example, four preforms 118 supplied from the supply unit 110 in the conveyance direction A of the preform, and a plurality of, for example, infrared heaters 304 as heat sources. A heating unit 111 having a heating box 302 and a rotation driving mechanism (not shown) are included.

  As shown in FIGS. 2 to 4, the first conveyance path 200 includes, for example, a plurality of first conveyance members 206 that hold four preforms 118 in an inverted state, and the first conveyance member 206 in the conveyance direction of the preforms. A forward path 220 for transporting to A, a return path (not shown) for transporting the first transport member 206 in the opposite direction to the forward path 220, and an unillustrated transport for transporting the first transport member 206 intermittently along the transport direction A for the preform 118. A first transport mechanism. The forward path 220 is on the upper surface side of the first transport path 200, and the preform 118 passes through the heating box 302, and the return path is below the forward path 220, and the first transport member 206 is transported back to the supply unit 110. To do. The first transport mechanism (not shown) includes two sets of first transport sprockets connecting the forward path 220 and the return path, and first transport drive means including a servo motor. For example, in the forward path 220, the first transport member 206 is intermittently driven by the first transport drive means in the preform transport direction A (return path 222 is in the reverse direction) by one pitch L. Moving.

  Each first conveying member 206 can hold, for example, four preforms 118 in a direction orthogonal to the preform conveying direction A, and thus preforms in four rows in a direction orthogonal to the preform conveying direction A. Is transported. A plurality of first conveying members 206 are arranged in a state where adjacent first conveying members 206 are in contact with each other in the preform conveying direction A, and eight first conveying members 206 are arranged in the heating box 302. Each first conveying member 206 is a plate-like bracket 212 extending in a direction orthogonal to the preform conveying direction A, and is rotatably attached to the bracket 212, and the preform support portion 214 that protrudes from the upper surface of the bracket 212. And a rotation mechanism 35 for rotating the preform support portion 214. The rotation mechanism 35 includes a rotation sprocket 38 and a rotation pulley 216 fixed to the preform support portion 214. Each of the first conveying members 206 has the rotation sprockets 38 provided on the preform support portions 214 at both ends of the first conveyance path 200, and the rotation pulleys 216 provided at the lower ends of all the preform support portions 214 are automatically rotated. They are connected by a conversion belt 217. Then, the neck portion 120 of the preform 118 is inserted into the preform support portion 214 so that the preform 118 can be supported in an inverted state.

  The heating box 302 is disposed in the heating unit 111 in the middle of the forward path 220 of the first transport path 200, and heats the preform 118 supported by the first transport member 206 to a temperature appropriate for blow molding. Two sets of heating boxes 302 are provided on the supply unit 110 side and the transfer unit 114 side along the conveyance direction A of the preform 118. In FIG. 2, for the sake of explanation, a part of the heat insulating material 320 is notched, and the conveyance state of the preform 118 is shown. Each heating box 302 has a plurality of, for example, eight stages of infrared heaters 304 extending along the preform conveying direction A in the axial direction of the preform 118, and on the opposite side of the infrared heater 304 with the preform 118 interposed therebetween. Includes a plate-shaped heat insulating material 320. Therefore, the heating unit 111 has a plurality of conveyance paths 201 that convey the preform 118 in series in opposition to the infrared heater 304. In the present embodiment, as shown in FIG. 4, from the left side of the figure, the heat insulating material 320, the preform 118, the infrared heater 304, the infrared heater 304, the preform 118, the heat insulating material 320, the preform 118, the infrared heater 304, The infrared heater 304, the preform 118, and the heat insulating material 320 are arranged in this order, and the preforms 118 in the four rows of conveyance paths 201 can be heated simultaneously. In each heating box 302, for example, eight preforms are arranged in series along the preform transport direction A (each transport path 201), and therefore, 32 (8 × 4 rows) in each heating box 302. The preform is temporarily stopped and heated. The preform 118 disposed in the heating box 302 rotates the rotation sprocket 38 by a rotation driving mechanism (not shown), and rotates the rotation pulley 216 and the rotation belt 217 while rotating the light (radiant heat) of the infrared heater 304. By applying, the preform 118 can be uniformly heated in the circumferential direction.

  The preform support portion 214 is a first support portion inserted into the neck portion 120 of the preform 118, and a cylindrical shape below the first support portion and having substantially the same diameter as the outer diameter of the neck portion 120. The second support part and a third support part rotatably attached to the bracket 212 are provided. The preform 118 is inserted into the first support portion and the neck portion 120 is placed on the second support portion and supported in an inverted state. A rotation sprocket 38 and a rotation pulley 216 are fixed to the third support portion. The preform 118 is held on the second support portion in a state in which the first support portion is inserted into the neck portion 120, and can be rotated as the preform support portion 214 rotates.

  As shown in FIG. 5, the first shutter member 306 and the second shutter member 308 are formed of thin metal plates, and are disposed to face each other with the preform 118 arranged along the conveyance path 201. Both shutter members 306 and 308 have N semicircular cutouts 314 having a slightly larger diameter than the preform support ring 120b on opposite sides. The notch 314 is shown by omitting the preform in only one row in FIG. When both shutter members 306 and 308 are close to the preform 118, the notch portions 314 facing each other form an arc-shaped hole 315, and the preform 118 is received in the hole 315. In this state, both shutter members 306 and 308 are at the height position of the support ring 120 b of the neck portion 120, and the neck portion 120 of the preform 118 carried into the heating box 302 is irradiated with light (radiant heat) of the infrared heater 304. Can be shielded from. Four sets of the first shutter member 306 and the second shutter member 308 are arranged corresponding to each heating box 302, and neck portions of 4 rows × 8 preforms 118 that temporarily stop in the heating box 302. 120 is protected from light (radiant heat) from the infrared heater 304. The notch 314 only needs to be formed in at least one of the first shutter member 306 and the second shutter member 308, and is formed in both shutter members 306 and 308 as in the present embodiment. In this case, the neck portion 120 can be reliably protected. Further, it is desirable that the notch 314 is formed with N notches 314 for receiving N preforms 118 stopped at a position facing at least the heat source (infrared heater).

  The shutter drive mechanism 340 moves the first shutter member 306 and the second shutter member 308 closer to and away from the preform 118 stopped on the transport path 201. The shutter drive mechanism 340 includes a columnar first rotation shaft 310 provided on the first shutter member 306, a second rotation shaft 312 provided on the second shutter member 308, and a first rotation shaft. Rotating means 314 for rotating 310 and the second rotating shaft 312. As shown in FIGS. 2 and 3, the rotating means 341 includes an air cylinder 342 fixed to the preform carry-in side of each heating box 302, a first elevating plate 344, a second elevating plate 346, One lifting rod 348, a second lifting rod 350, a rack member 352, and a pinion member 354 are provided. The air cylinder 342 is a rotary air cylinder, and can drive the cylinder rod 360 protruding upward and the cylinder rod 362 protruding downward simultaneously. The first lift plate 344 is fixed to the upper end of the cylinder rod 360 of the air cylinder 342, and the second lift plate 346 is fixed to the lower end of the cylinder rod 362. The first elevating rod 348 and the second elevating rod 350 are suspended from the first elevating plate 344 and the second elevating plate 346, respectively, and the rack members 352 are respectively fixed to the lower ends thereof. Yes. Both ends of the first rotating shaft 310 and the second rotating shaft 312 are rotatably held by the heating box 302. A pinion member 354 is fixed to the tips of the first rotating shaft 310 and the second rotating shaft 312 and meshes with the rack member 352 to constitute a so-called rack and pinion mechanism.

(Transfer part)
As shown in FIG. 1, the transfer unit 114 transfers the four preforms 118 heated by the heating station 112 to the blow molding station 116. The transfer unit 114 includes a transfer mechanism (not shown) that holds the preform 118 in an inverted state and delivers it to the blow molding station 116 in an inverted state.

(Blow molding station)
The blow molding station 116 includes a receiving unit 402, a blow molding unit 404, and a take-out unit 406 along the second conveyance path 400. The second transport path 400 has a substantially rectangular shape, is disposed with one side where the receiving unit 402 is disposed facing the transfer unit 114, and includes a second transport mechanism 410. The second transport mechanism 410 intermittently conveys a plurality of second transport members 408 along the second transport path 400, and includes four sprockets 416 disposed at the corners of the transport path of the second transport path 400, and these A second transport chain 418 spanned over the sprocket 416, a second transport rail (not shown) disposed on the outer periphery of the second transport chain 418, and a second transport member fixed to the second transport chain 418 at predetermined intervals. 408 and a motor (not shown) connected to any one of the four sprockets 416. By driving a motor (not shown), the second transport chain 418 is intermittently rotated along the second transport path, and is intermittently transported by one molding cycle every four second transport members 408.

  The second conveying member 408 supports and conveys the preform 118 in an inverted state, and supports the preforms one by one.

(Description of molding method)
Next, a blow molding method using the aforementioned blow molding apparatus 100 will be described.

  First, a 1st conveyance process is demonstrated. The first transport process includes a supply process and a heating process in which the preform 118 is heated while rotating.

  In the supply process, as shown in FIG. 1, in the supply unit 110, four preforms 118 are aligned in a row at a blow molding pitch in an upright state. Then, the four preforms 118 aligned are inverted by an inversion delivery mechanism (not shown), and the preform 118 is delivered to the first conveying member 206 of the heating station 112.

  In the heating process, the preforms 118 are intermittently transported through the heating station 112 while being held by four first transport members 206 of the first transport path 200 provided along the transport direction A of the preform 118. The preform 118 is intermittently conveyed while rotating on a conveyance path 201 in the heating box 302 by a rotation driving mechanism (not shown), and is heated to a temperature appropriate for blow molding.

  Hereinafter, the heating process will be described in more detail with reference to FIGS.

  3 and 4, the right half shows the preform stopped state, and the left half shows the preform transport state. First, when the preform 118 is transported along the transport path 201 of the first transport path 200, the cylinder rod 360 is lifted by the air cylinder 342 of the rotating means 341 as shown in the left half of FIGS. And the cylinder rod 362 is lowered. When the cylinder rod 360 is lifted, the first lifting plate 344 connected thereto, the first lifting rod 348, and the rack member 352 fixed to the tip of the first lifting rod 348 are lifted, and these The pinion member 354 that meshes with the rack member 352 rotates to rotate the second rotating shaft 312 disposed below the infrared heater 304. By the rotation of the second rotation shaft 312, the second shutter member 308 arranged around the support ring 120 b rotates 90 degrees downward and retracts below the infrared heater 304. When the cylinder rod 362 is lowered, the second lifting plate 346 connected thereto, the second lifting rod 350, and the rack member 352 fixed to the tip of the first lifting rod 350 are lowered. Then, the pinion member 354 engaged with the rack members 352 rotates to rotate the first rotating shaft 310 disposed on the heat insulating material 320 side. Due to the rotation of the first rotation shaft 310, the first shutter member 306 arranged around the support ring 120 b rotates 90 degrees upward and retracts to the side of the body 121 of the preform 118. As described above, the first shutter member 306 and the second shutter member 308 rotate, so that there is no obstacle in the transport direction of the preform 118, and the preform 118 can be transported.

  Next, when the preform 118 is stopped and heated in the conveyance path 201 of the first conveyance path 200, as shown in the right half of FIG. 3 and FIG. The rod 360 is lowered and the cylinder rod 362 is raised. When the cylinder rod 360 is lowered, the first lifting plate 344, the first lifting rod 348, and the rack member 352 fixed to the tip of the first lifting rod 348 are lowered. The pinion member 354 that meshes with the rack member 352 rotates to rotate the second rotating shaft 312 disposed below the infrared heater 304. Due to the rotation of the second rotation shaft 312, the second shutter member 308 rotates 90 degrees upward and is disposed again around the support ring 120b. When the cylinder rod 362 is lifted, the second lifting plate 346 connected thereto, the second lifting rod 350, and the rack member 352 fixed to the tip of the first lifting rod 350 are lifted. Then, the pinion member 354 engaged with the rack members 352 rotates to rotate the first rotating shaft 310 disposed on the heat insulating material 320 side. Due to the rotation of the first rotation shaft 310, the first shutter member 306 rotates 90 degrees downward and is disposed around the support ring 120b. As described above, the first shutter member 306 and the second shutter member 308 are arranged around the support ring 120b, whereby the light of the infrared heater 304 is blocked and the neck portion 120 of the preform 118 is heated. To prevent that. In particular, as shown in FIG. 5, the hole 315 formed by the notch 314 when both shutter members are close to the preform 118 has a slightly larger inner diameter than the support ring 120b. The portion 120 can be efficiently protected from the light of the infrared heater 304. In addition, the notch portions 314 formed at both ends of the preform carry-in side and the carry-out side of both shutter members 306 and 308 are formed in a quarter arc shape and do not surround the entire circumference of the support ring 120b. Since only the mounting portion of the infrared heater 304 is disposed beside the preform 118 at the position, the neck portion 120 is not affected by heat. However, if the shutter members 306 and 308 extend beyond the length of the infrared heater 304 in this way and the quarter arc-shaped cutout portions 314 are provided at both ends thereof, the diffusion of light from the infrared heater 304 is caused. Is desirable.

  As described above, when the second rotating shaft 312 is disposed below the infrared heater 304 and the second rotating shaft 312 is rotated toward the infrared heater 304 side, the second shutter member 306 is retracted below the infrared heater. Therefore, the shutter members 306 and 308 are not always arranged between the infrared heater 304 that is a heat source and the preform body 120.

  In the transfer step, the preform 118 transferred to the transfer unit 114 is transferred to the second transfer path 400 of the blow molding station.

  Next, a 2nd conveyance process is demonstrated.

  The second transport process includes a blow molding process for blow molding the transferred preform 118 and a take-out process.

  In the blow molding process, when the four second transport members 408 stopped by the receiving unit 402 of the blow molding station 116 receive one preform 118 at a time, they are intermittently transported to the blow molding unit 404 by the second transport mechanism 410. The A blow cavity mold is clamped by a mold clamping mechanism (not shown) with respect to the preform 118 stopped at the blow molding unit 404, and stretch blow molding is performed to mold the container 428.

  Then, the container 428 is intermittently conveyed to the extraction unit 406, and in the extraction process, the container 428 is extracted from the second conveyance member 408 and discharged from the blow molding apparatus 100.

  The present invention is not limited to the above-described embodiment, and can be changed to various embodiments within the scope of the gist of the present invention.

  For example, in the above embodiment, the heat source is an infrared heater, but a known heat source such as a hot air generator or a microwave generator may be employed. In that case, the heat from the heat source in the present invention corresponds to hot air or microwaves.

It is a top view which shows the whole structure of the blow molding apparatus concerning one embodiment of this invention. It is a side view of the heating part concerning one embodiment of the present invention. It is a front view of the shutter drive mechanism concerning one embodiment of the present invention. It is X-X 'sectional drawing of FIG. 2 of the heating box concerning one embodiment of this invention. It is a top view of the shutter member concerning one embodiment of the present invention.

Explanation of symbols

35 Rotating Mechanism 100 Blow Molding Device 111 Heating Unit 112 Heating Station (300 Preform Heating Device)
114 Transfer section 116 Blow molding station 118 Preform 200 First transport path 206 First transport member 302 Heating box 306 First shutter member 308 Second shutter member 340 Shutter drive mechanism 341 Rotating means 400 Second transport path 408 Second Conveying member

Claims (3)

Netw click portion, intermittently a cylindrical barrel portion continuous to the neck portion, each of the plurality of preforms to be closed and the bottom for closing the body portion, respectively, in an inverted state in which the neck portion downwardly A transport route for transport;
A heat source for simultaneously heating the body portions of the plurality of preforms conveyed in an inverted manner;
A first shutter member and a second shutter member which are arranged opposite to each other with the conveyance path interposed therebetween and which block heat from the heat source with respect to the neck portion;
A shutter drive mechanism for moving the first shutter member and the second shutter member toward and away from the plurality of preforms stopped in the transport path;
Have
At least one of the first shutter member and the second shutter member has a plurality of cutout portions sized to receive the plurality of preforms stopped on the transport path,
The shutter drive mechanism is
A first rotating shaft provided on the first shutter member and extending along the transport path in one of the two sides sandwiching the transport path;
A second rotating shaft provided on the second shutter member and extending along the conveying path in the other region facing the first rotating axis across the conveying path;
A rotating means for rotating the first rotating shaft and the second rotating shaft by a single drive source;
Have
The heat source includes a plurality of infrared heaters extending along the transport path in a region above the second rotation shaft,
A preform heating apparatus in which , when the plurality of preforms are moved, the second shutter member is retracted below the plurality of stages of infrared heaters by driving the second rotating shaft . In claim 1,
The rotation locus range of the second shutter member is below a horizontal line passing through the second rotation axis in an arc centered on the second rotation axis in a cross section orthogonal to the conveyance path. Preform heating device that is a quarter arc region on the side . In claim 2,
The range of rotation trajectory of the first shutter member is above the horizontal line passing through the first rotation axis in an arc centered on the first rotation axis in a cross section orthogonal to the transport path. A preform heating device that is a quarter arc region .

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