JPH03224715A - Double-stage orientation blow molding device - Google Patents

Abstract

PURPOSE:To enhance orientation properties and manufacture a molded product with upgraded resistance to heat and barrier properties by orientation blowing by a first blow molding machine, and reheating, shrinking, and orientation blow molding by a second blow forming machine machine 7. CONSTITUTION:A preform P is loaded on a core bar 8, and the preform P and the core bar 8 having passed through a preliminary heating device 2 are transferred from a second core bar holder 60 to a first blow molding machine 6 by a second loading rotator 50b. A first blow molding is carried out on the first blow molding machine 6 while a third rotator 70 rotates one round, and the perform P is loaded into a preliminary orientation molded product. After that, the same passes through a secondary heating device 3, a preliminary orientation molded product is heated. The same is incorporated into a mold of a blow forming machine 7 and biaxially oriented while a fourth rotator 50d rotates one round, and final molded product is fed out by a feed-out device 40.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heated stretch blow molding apparatus, and particularly to a two-stage stretch blow molding apparatus in which stretch blowing is performed in two stages.

[Conventional technology]

Yoto: As a device that automatically performs heated stretch blow molding,
A device described in Japanese Unexamined Patent Publication No. 55-90318 is known.

This equipment transports and transports a core metal into which a bottomed cylindrical preform made of synthetic resin (preformed product before blow molding) is attached.
This device is equipped with a loading/unloading device for loading and unloading, a heating device that heats the preform attached to the core metal, and a stretch blow molding machine that stretches and blows the preform heated by the heating device and molds it into a container. .

The core metal is configured to circulate through each of the devices, the loading/unloading device has a first rotary table, the heating device has a second rotary table, and the blow molding machine has a second rotary table. It has a third rotary table.

The first rotary table of the loading/unloading device has holding pieces for holding the cored metal attached at regular intervals on its peripheral edge, and the second rotary table IL of the heating device rotates the cored metal holder for holding the cored metal around the periphery. The third rotary table of the blow molding machine has blow molding molds arranged at equal intervals around the third rotary table, which are arranged at equal intervals at the end thereof. The preform is heated by passing it through a heating device by rotating a rotary table, and then blow molded in a blow molding machine.

The first rotary table and the second rotary table rotate in opposite directions, and the second rotary table and third rotary table also rotate in opposite directions. Then, the metal core on which the preform is mounted is transferred from the holding piece of the first rotary table to the core metal holder of the second rotary table. After being attached to the mold together with the core metal and blow-molded, the molded product and the core metal are transferred to a holding piece of the first rotary table. The product is removed from the core metal on this first rotary table, and a new preform is attached to the core metal and transferred to the second table. This process is repeated until the gourd container is continuously blow-molded.

[Problem to be solved by the invention]

By the way, with such conventional equipment (Dai), the degree of orientation of the molecular chains is low because the stretching is performed only once, and in the case of bottles made of polyethylene terephthalate, there is no heat resistance temperature of 80 to 87 degrees Celsius. There is also the problem of low barrier properties.In particular, when carbon dioxide gas and fruit trees are sealed and sterilized at 60℃ for 40 minutes, containers produced using the conventional one-stage blowing method tend to have their shoulders protruding or their bottoms downward. The present invention was developed in view of this problem, and it is possible to improve orientation by performing stretching twice, thereby obtaining a molded product with improved heat resistance and barrier properties. The goal is to create a device that can do this automatically, and the challenge is to create a device that can do it automatically.

[Means to solve the problem]

In order to solve the above problems, the present invention provides the following device.

The apparatus of the present invention has a core metal 8 that is circulated from the carry-in/out device 5 to the carry-in/out device 5 via the primary heating device 2, the primary blow molding l16, the secondary heating device 3, and the secondary blow molding machine 7. A bottomed cylindrical synthetic resin preform P is held at the receiving position of the feeding device 5, and after this preform P is heated by the primary heating device 2, it is stretched into a pre-stretched molded product by the primary blow molding machine 6. After that, the pre-stretched molded product is reheated and shrunk in the secondary heating device 3, and then stretched and blow molded into the final molded product in the secondary blow molding machine 7, and then,
This is a two-stage stretch blow molding device in which the final molded product is removed from the core bar 8 upon returning to the carry-in/out device 5 and taken out.

The loading/unloading device 5, primary heating device 2, primary blow molding machine 6, secondary heating device 3, and secondary blow molding machine 7 are as follows:
The loading/unloading device 5 is provided along the circumference of the first rotary body 1, and has a second rotary body 22, and this second rotary body 22 has a first core metal holder 45 that holds the core metal 8. A plurality of core metals are provided around the periphery, and the core metal 8 holding the preform P is transferred from the first core metal holder 45 to the first rotating body 1. 2nd to hold gold 8
The primary blow molding machine 6 has a large number of core metal holders 60, and receives the core metal 8 holding the preform P from the second core metal holder 60 of the first rotating body 1, and then internalizes the preform P. A large number of primary blow molding molds 71 are provided around the third rotating body 70,
The primary blow molding die 71 is used to perform stretch blow molding into a pre-stretched product, and the core bar 8 is delivered together with the pre-stretched product to the second core holder 60 of the first rotating body l, and the secondary blow molding is carried out. The molding machine 7 receives the core metal 8 holding the heat-shrinked pre-stretched molded product after passing through the secondary heating device 3, and then transfers the secondary blow-molding metal 78 into which the pre-stretched molded product is placed inside. The secondary blow molding mold 78 is used to stretch-blow mold the final molded product, and the core bar 8 is transferred together with the final molded product to the loading/unloading device 5.
A two-stage stretch blow molding apparatus was constructed in such a manner that the molded product was transferred to the second rotating body 22 of the machine.

[Effect]

In the apparatus of the present invention, the preform P is stretch-blown into a pre-stretched molded product in the primary blow molding 8t6, then reheated and shrunk, and then stretch-blown into a final molded product in the secondary blow molding machine 7. Two stages of stretch blowing are performed.

Therefore, the degree of orientation of the molecular chains of the resin constituting the molded article is improved.

In addition, since the loading/unloading device 5, the primary heating device 2, the secondary blow molding machine 6, the secondary heating device 3, and the secondary blow molding 8!7 are provided along the circumference of the first rotating body l, It can be installed rationally within the building and saves space.

〔Example〕

Hereinafter, the present invention will be explained in detail based on the drawings.

(Example 1) Outline of overall structure> As shown in FIG. It is structured around a heating tower 4 having a circular planar shape, and around this heating tower 4, a loading/unloading device 5 including a loading device 20 and a loading device 40, and a primary blow molding machine 6 are installed.
, a secondary blow molding machine 7 is arranged. The molding machine 7 is located between the loading/unloading device 5 and the secondary heating device 3.

Then, from the loading/unloading device 20 of the loading/unloading device 5 to the primary heating device 2, the primary blow molding 8!6, the secondary heating device 3, the primary blow molding machine 7, the loading/unloading device 40 of the loading/unloading device 5, and then the loading/unloading device 5. A core metal 8 holding a synthetic resin preform P is circulated to a carrying-in device 20 .

Furthermore, if the stretching rod 9e of the core bar 8 does not come down between the carrying-in device 20 and the carrying-out device 40 for some reason,
Or, if a product is not taken out and remains on the core bar 8, a core bar replacement device 80 is provided which automatically checks the product and replaces the core bar with a spare one to prevent the machine from stopping.

Hereinafter, the structure of this core metal 8 will be explained, and then the structure of each part will be explained in the order of manufacturing steps.

Core Metal> As shown in FIG. 15, the main parts of the core metal 8 include a mandrel 9a, a neck support 9b, a core guide 9C, a spacer ring 9d, and a stretching rod 9e.

The mandrel 9a has a flange-shaped disk portion 9f and this disk portion 9.
Cylindrical cylinder portion 9g hanging vertically from the center of the lower surface of f
The inner space of the cylinder portion 9g is opened directly to the center of the disk portion 9f.

Cylinder part 9g1f in this mandrel 9a,
It is made of a magnetic material with high magnetic permeability, such as steel, so that it is magnetically attracted and transported when circulating through each of the above devices.

The neck support 9b placed and fixed on the disk portion 9f of the mandrel 9a supports the outer periphery of the neck portion of the preform P, and is assembled onto the mandrel 9a via a heat insulating plate 9h. That is, the neck support 9b has an insertion hole opened upward in the center thereof into which the neck of the preform P can be inserted.

The core guide 9C, which is irremovably assembled inside the cylindrical neck support 9b, allows the extension rod 9e located on the central axis of the core bar 8 to smoothly slide up and down, and maintains its posture. It is made of synthetic resin such as Teflon.

The upper half of the core guide 9C facing the insertion hole of the neck support 9b has a cylindrical shape and is inserted into the neck of the preform P.

A stretching rod 9 is placed in the mandrel 9a below the core guide 9c.
Spacer ring 9 for adjusting the stretching stroke of e
d is fitted. A stretching rod 9e arranged movably up and down on the central axis of the core bar 8 is connected to a blow molding machine (6, 7).
When assembled into the blow molding mold (71, 78),
The blow molding machine (6, 7) lifts the assembled preform P by the push-up action using the stretching bins, and stretches the assembled preform P in the axial direction. At the same time, a core top 91 made of a heat insulating material (for example, Teflon) and having an inverted truncated cone shape with an inverted tapered surface is assembled to prevent the preform P from clinging, and is also located within the cylinder portion 9g. There is a piston-shaped nozzle holder 9 at the bottom end.
j is assembled.

An air passage button for pressurizing the pressurized air from the pressurized air supply device 73 of the blow molding 0I (6, 7) into the preform P is formed in the stretching rod 9e and the nozzle holder 9j.

This air passage 9m first has a T-shaped hole 9k on the side in the protruding part of the nozzle holder 9j with which the stretching bottle comes into contact.
This hole 9 communicates with an air passage 9m formed rising inside the extension rod 9e, and this air passage 9m has an opening formed in the shape of a spline groove over almost the entire length of the extension rod 9e. 91 is opened.

The reason why the air passage 9m is opened into the preform P held by the core bar 8 through the opening 91 formed in the shape of a spline groove is because the preform P is stretch-molded in the radial direction. Blow pressure is 50Kg/cnr
Since the pressure value is quite high, forming an air passage button in which the stretching rod 9e has a hollow structure over a long range of the stretching rod 9e will result in insufficient mechanical strength. By opening in the shape of a spline groove, the pressurized air for blow molding will not be ejected locally.Therefore, there is a risk that defective molding marks such as dimples may remain on the wall surface of the preform P due to the air jet. disappears.

The core metal 8 configured as described above holds the bottomed cylindrical synthetic resin preform P at the receiving position of the loading/unloading device 5, and
This preform P is primarily heated when the core metal 8 passes through the primary heating device 2, and then stretch blown into a pre-stretched molded product by the primary blow molding machine 6. Next, the preform P is reheated in the secondary heating device 3 and stretch blow molded into a final molded product in the secondary blow molding machine 7. Thereafter, upon returning to the loading/unloading device 5, the final molded product is removed from the core bar 8, while a new preform P is attached to the core bar 8, and the core bar 8 is circulated again.

Carrying-in device in the carrying-in/out device> Next, the carrying-in device 20 in the carrying-in/out device 5 will be explained based on FIGS. 1 to 5.

This loading/unloading device 51 is equipped with a loading/unloading device 2o and a loading/unloading device 40 on a base 21. It is provided facing the second rotating body 22.

As shown in FIG. 21, the carrying-in device 20 has a feeding machine 24 that supplies preforms P sent by a conveyor 23 from an injection molding machine (not shown) in a straight line in a straight line. This feeding machine 24 has a structure in which the flange portion P1 around the neck of the preform P is supported on both sides of the feeding machine 24.

A distributing device 25 for distributing the preform P into the left and right first branching gutter 29a and the second branching gutter 29b is provided at the tip of the supplying machine 24. This sorting device 25 is provided with support holes 27 for supporting the preform P at intervals of 120 degrees around a rotating disk 26, and a stepping motor 2
8, it rotates forward and backward every 120 degrees or in one direction. When the supply machine 24 is taken as the origin, a first branching gutter 29a and a second branching gutter 29b are provided at 120 degrees and 240 degrees around the rotating disk 26, respectively.

Further, on the opposite side of the supply machine 24, a branch arm 30 is pivotally fixed by a shaft 31.
The air cylinder devices 32 are arranged so that the tip of the branch arm 30 swings under the action of each air cylinder device 32.

Then, by the swinging motion, the preform P located in the support hole 27 is moved to the first branch gutter 29a or the second branch gutter 2.
Play it to 9b and distribute it.

Normally, the rotating disk 26 rotates forward and backward every 120 degrees,
The branch arms 30 alternately transfer the preform P to the first branch trough 2.
9a and the second branch gutter 29b.

A preform P detection sensor (not shown) is provided at each base end of the first branch gutter 29a and the second branch gutter 29b.
If the preform P is no longer detected in any of the channels (b), the branch arm 30 continuously supplies the preform P to the other gutter, that is, the gutter on the side where the preform is consumed more. In that case, the rotating disk 26 is adapted to rotate in one direction.

As a result, the preforms P are distributed almost equally between the first branching gutter 29a and the second branching gutter 29b.

Further, as shown in FIG. 4, at the tips of the first branch gutter 29a and the second branch gutter (29a, 29b), a gear-shaped rotary disk 33 is perpendicular to each branch gutter (29a, 29b). The placed tags are designed to be rotated.

Each rotary disk 33 is provided with a plurality of holding grooves radially centering on the rotary shaft to receive the preform P bowed from each branch gutter (29a, 29b) in a royal state. Then, the preform P from each branch gutter (29a, 29b) is delivered to the holding groove of the upper body of the rotary disk 33 in an upright state, and is reversed by half a rotation of the rotary disk 33 to become an inverted state.

A tongue piece 35 for supporting the inverted preform P is provided below each rotary disk 33, and is adapted to receive and support the preform P. This supporting tongue piece 35 has a suction hole 36 bored in the center, and this suction hole 36 is connected to a vacuum pump (not shown).
The received preform P is suctioned and fixed to the supporting tongue piece 35 by suction force. In addition, the supporting tongue piece 35
is movable forward and backward by a second air cylinder device 37, and is adapted to hold out the preform P toward the second rotating body 22.

The second rotating body 22 has a preform holding part 42 at the tip of an arm 41 provided radially at an angle of 30 degrees, and this preform holding part 42 holds the preform P in an arc-shaped recess. . An arcuate plate-shaped guide 4 surrounds the second rotating body 22 and holds the preform P so that it does not come off between it and the preform holding part 42.
3 is provided.

This guide 43 has a preform P at each angle of 30 degrees.
An inlet 44 is provided for inserting the.

Then, around the second rotating body 22, the bead holding section 4
A first core metal holder 45 made of a magnet is provided at the lower part of the second core holder 45. The core metal 8 is attracted and held by the first core metal holder 45, and the core metal 8 is conveyed to the tenth rotating body 50a. It looks like this.

The preform P inserted from the entrance 44 of the guide 43 onto the tongue piece 35 and inserted into the second rotary body 22 side (the preform P is held by the preform holder 42 at the tip of the rotating arm) is scraped off in the direction of rotation. At that time, it falls off the tongue piece 35 and is attached to the core bar 8.

The core bar 8 with the preform P mounted thereon is delivered to the heating tower 4 by the tenth rotary body 50a.

This 10th ding rotating body 50a 14 7th is
As shown in FIG. 8, it has three arms 51 and is equipped with a magnet 52 at the tip of each arm 51 to attract and hold the core metal 8. A cam unit 53 controls the rotation of the second rotating body 22 and The core bar 8 is rotated in synchronization with the first rotating body 1 of the heating tower 4, and the core bar 8 held by suction is transferred from the first core bar holder 45 of the second rotating body 22 to the first rotating body 1 of the heating tower 4. It is designed to be delivered to a plurality of second core metal holders 60 provided on one rotating body 1.

In addition, each loading rotary body 50b to 50 described below
f also has the same structure as the tenth rotating body 50a. However, four or more arms 51 may be provided if necessary.

Heating tower and primary heating device installed in the heating tower The heating tower 4 has the first rotating body 1 as shown in FIG.
The rotating body 1 is rotationally driven by a drive gear (not shown) that meshes with a rack 1a carved around the circumference. and,
The first rotating body 1 has a plurality of second core metal holders 60 around it, receives the core metal 8 on which the preform P is mounted from the tenth rotating body 50a, and connects the primary heating device 2 to the core metal holder 60.
is adapted to pass while rotating while holding the preform P. That is, a fixed table 62 with a rack 61 carved around the periphery is provided on the lower side of the first rotating body 1. As shown in FIG. A core metal holding part 64 is rotatably provided in a cylindrical frame 63, and this core metal holding part 64 has a magnet part 65 on the upper part that attracts and holds the core metal 8, and also has a lifting shaft 66 that rotates. A pinion gear 67 that meshes with the rack 61 of the fixed table 62 is provided at the lower part of the elevating shaft 66.
When it revolves, the elevating shaft 66 rotates due to the engagement between the rack 61 and the pinion gear 67, and the core holding portion 64 rotates accordingly.

Thereby, the preform P held by the second core metal holder 60 is heated while rotating and revolving around the primary heating device 2 .

The preform P and core metal 8 that have passed through the primary heating device 2 are transferred from the second core metal holder 60 to the primary blow molding machine 6 by the 20th ding rotating body 50b.

11 is as shown in FIG. 12. At the delivery position of the cored metal 8, the binion gear 67 is meshed with the intermittent rotation gear 69, and the cored metal 8 is temporarily rotated during the first rotation while being aligned in the direction in which the cored metal 8 can be delivered. In synchronization with the movement of body 1, the binion gear 6
7 and the frame 63, and in the meantime, the cam mechanism 68 raises the pinion gear 67 to separate it from the rack 61, and the frame 63 and the pinion gear 67 keep the orientation constant. Moreover, the core metal holding part 64 is rotated so that the core metal holding part 64 does not get in the way of transferring the core metal 8.

Primary Blow Molding Machine> This primary blow molding machine 6 has a third rotating body 70 as shown in FIG. 13, and a plurality of primary blow molding molds 71 are provided around this third rotating body 70. It is being

This mold 71 is assembled to the third rotating body 70 by a support shaft, and a double-split mold 71a is formed into a so-called double-opening centering around this support shaft.
and a bottom mold 71b that forms the bottom of the pre-stretched product.

A pressurized air supply device 73 for inserting pressurized air into the preform P via the core bar 8 assembled to the mold 71 is provided below the mold 71 . Also,
A stretching pin 74 is vertically movable and inserted through the pressurized air supply device 73 into the cylinder portion 9g of the core metal 8 on which the loss mold 71 is attached.
It is now possible to push up e.

This primary blow molding mold 71 is clamped at the same time as the core metal 8 is assembled by a cam mechanism (not shown).
During one rotation with the rotating body 70, stretching in the radial direction by supplying pressurized air and stretching in the axial direction by pushing up with the stretching rod 9e is performed, and primary blow molding is performed. Gourd pressure air is removed. Then, when it approaches the heating tower 4, the mold is opened by the cam mechanism.
The core metal 8 holding the pre-stretched product is delivered to the second core metal holder 60 provided on the first rotating body 1 by the 30th rotating body 50c. The mold 71 moves together with the third rotating body 70 in an open state to a position where the core metal 8 is received, the core metal 8 is assembled, and the blow molding is repeated.

The core metal 8 holding the pre-stretched molded product returned to the core metal holder again by the 30th ding rotor 50c is reheated while passing through the secondary heating device 3 provided in the heating tower 4. Then, it moves to the secondary blow molding machine 7.

Secondary heating device installed in the heating tower> The secondary heating device 3 has the same configuration as the primary heating device 2,
The pre-stretched molded product is heated and shrunk. The pre-stretched product after heating is transferred to the secondary blow molding mold 7 of the secondary blow molding machine 7 together with the core metal 8 by the 40th ding rotor 50d.
At step 8, the final molded product is assembled and biaxially stretched.

Secondary Blow Molding Machine> This secondary blow molding machine 7 has the same configuration as the primary blow molding machine 6 described above, and is equipped with a plurality of molds 78 for secondary blow molding around the fourth rotating body 77. In addition, the secondary blow molding mold 78 has the same structure as the primary blow molding mold 71 except that the cavity is set to be smaller.
a and a bottom mold 78b that forms the bottom of the product.

When the final molded product is molded in the secondary blow molding machine 7, the core metal 814 that holds it and the 50th ding rotor 50
At e, the metal core holder 45 of the second rotating body 22 is transferred. Here, the final molded product is removed from the core metal 8 by the carry-out device 40 and carried out.

In addition, in the 50th rotary body 50e, the core metal 8 is transferred from the secondary blow molding machine 7 to the second core metal holder 60 of the first rotary body 1.
After handing over the first core metal holder 4 of the second rotating body 22
Alternatively, the core bar 8 may be delivered to the terminal 5.

Unloading device> The unloading device 40 is a device that holds the final molded product between a pair of rotating endless belts, removes it from the core metal 8, and transfers it to a conveyor, where the final molded product is sent to the next process. be done.

Core Metal Replacement Apparatus> Incidentally, the core metal 8 that is equipped with the preform P that has failed in stretch blow molding for some reason cannot be removed by the unloading device 40.

In addition, there are cases where the final molded product is not removed from the core metal 8 by the carry-out device 40, and there are cases where the stretching rod 9e does not return to the core metal 8. Regarding such a core bar 8, an unmolded preform P
A core bar replacement device 80 is provided for removing the final molded product and replacing it with a new core bar 8.

That is, the first is the second rotating body 22 as shown in FIG.
A fifth rotating body 85 is provided on the base 21 in the vicinity of the third core metal holder 8 which attracts and holds the core metal 8 with a magnet around the fifth rotating body 85.
6 is provided. The first core metal holder 4 of the second rotating body 22 is disposed between the second rotating body 22 and the fifth rotating body 85.
The 60th rotating body 50f transfers the core metal 8 from the fifth rotating body 85 to the third core metal holder 86 of the fifth rotating body 85, and the third rotating body 50f transfers the core metal 8 from the third core metal holder 86 of the fifth rotating body 85 to the first core metal holder 86 of the second rotating body 22. A seventieth rotating body 50g for passing the core metal 8 over the core metal holder 45 is installed. Also, it is inspected to see if there is any abnormality in the core metal 8 sent to the fifth rotating body 85, for example, whether the preform P1 or the final molded product is attached or not, and whether the stretching rod 9e remains protruding. An abnormality detector 88 for the core metal 8 is installed on the fifth rotating body 85. This is made of phototubes.

Furthermore, a rotating stocker 91 having a fourth core metal holder 90 around it is provided near the fifth rotating body 85 , and between this rotating stocker 91 and the fifth rotating body 85 , a third The 80th ding rotor 50h transfers the core metal 8 from the core holder 86 to the fourth core holder 90 of the rotary stocker 91, and the 3 Core metal holder 86 and core metal 8
A 90th ding rotating body 50i is installed to deliver the 90th. Further, an air cylinder device 89 is provided from the fifth rotary body 85 side toward the 80th rotary body 50h. This air cylinder device 89 is an abnormality detector 88
If detects preform P or final molded product,
It is activated when an abnormality of the core metal is detected, such as when the stretching rod 9e detects the protruding core metal 8, and pushes the core metal 8 toward the 80th ding rotating body 50h.

Then, the core metal 8 sent from the second rotary body 22 to the fifth rotary body 85 is checked by an abnormality detector 88 to determine whether or not the preform P or the final molded product is attached to the stretching rod 9.
The core metal is inspected for abnormalities, such as whether or not e is protruding. The normal core bars 8 other than those mentioned above are transported as they are, and transferred to the second rotary body 22 by the aforementioned 70th ding rotary body 50g.A preform P is newly installed in the carrying-in device 20. The core metal 8 with the preform P or the final molded product installed is detected by the abnormality detector 88.
On the condition that it is detected by the air cylinder device 89, it is pushed by the air cylinder device 89 and handed over to the 80th ding rotary body 50h.Furthermore, from this 80th ding rotary body 50h, it is transferred to the fourth core metal holder 90 of the rotary stocker 91. be done. Here, the core bar 8 is repaired or replaced by removing the preform P by an operator or by using a preform removing device. Since the core metal 8 is removed from the fifth rotary body 85 to the rotary stocker 90, there is not enough core metal 8, so the fourth core metal holder 90 of the rotary stocker 91 is transferred to the third core metal of the fifth rotary body 85. The core metal 8 is supplied to the holder 86. For replenishment, the timing is calculated based on the detection result of the abnormality detector 88, and the rotary stocker 91 is rotated synchronously by clutch interlocking, and the 90th ding rotary body 501 is rotated to deliver the core metal 8.

Drive mechanism> With the above configuration, the first to fourth rotary bodies and the first to sixth rotary bodies are connected to each other in accordance with the timing of delivery to the core metal 8 and in consideration of the blow molding time. Each rotates at its own specific speed. The power source is one motor (M) as shown in Fig. 1, and the above-mentioned It is rotated like this.

Manufacturing process of two-stage blow-molded container> Next, how a two-stage blow-molded container is molded using the apparatus described above will be described.

The preform PIL is sent from the injection molding machine by the conveyor 23. It passes through the supply gutter 24, and is distributed to the first and second branch gutter by the distribution device 25. The gourd is inverted by the rotary plate 33. Each rotary plate The preform holding portion 42 of the second rotary body 22 is transferred from the entrance 44 of the guide 43.

Then, the preform holding section 4 together with the second rotating body 22
2 rotates, the preform P held in the preform holding part 42 falls from the supporting tongue piece 35, and
It is attached to the core metal 8 below. The core bar 8 on which the preform P is mounted is attached to the first rotating body 22 which is rotating together with the second rotating body 22.
It is held by the core metal holder 45 and transported.

From the first core metal holder 45 to the tenth rotating body 50a
The core metal holder 60 of the first rotating body 1 is delivered to the second core metal holder 60 of the first rotating body 1 through the rotation of the first rotating body 1. It is heated as it passes through.

The preform P and core metal 8 that have passed through the primary heating device 2 are transferred from the second core metal holder 60 to the primary blow molding machine 6 by the 20th ding rotating body 50b.

In the primary blow molding machine 6, primary blow molding is performed while the third rotating body 70 rotates once.The preform P is molded into a pre-stretched product. Thereafter, the core metal 8 is held in the state where the pre-stretched molded product is held, and the 30th ding rotating body 50c
Then, it is delivered to the second core metal holder 60 of the first rotating body 1.

The core bar 8, holding the pre-stretched product, revolves around its axis and passes through the secondary heating device 3, during which time the pre-stretched product is heated.

The pre-stretched molded product after heating is assembled into the secondary blow molding mold 78 of the secondary blow molding machine 7 by the 40th rotor 50d together with the core bar 8. The molded product is biaxially stretched.

The core metal 8 removed from the secondary blow molding mold 78 is moved to the 50th ding rotating body 50e while holding the final molded product.
The metal core holder 45 of the second rotary body 22 is then transferred to the first core metal holder 45 of the second rotating body 22. Next, the final molded product is transported out by the transport device 40.

If the core metal 8 passes through the abnormality detector 88 and no preform P is detected, it is transported to the carrying device 20, where the preform P is held again.

The core bar 8 on which the preform P or product was attached or the core bar 8 of the stretching rod 9e that has not returned properly is pushed by the air cylinder device 89 and transferred to the rotary stocker 91 via the 80th ding rotary body 50h. .

At the same time, the core metal 8 is transferred from the rotating stocker 91 to the fifth rotating body 85.
will be replenished.

When a two-stage stretch blow molded container manufactured using this device was filled with carbon dioxide gas and fruit trees and heat sterilized, no problems such as protruding shoulders or downward bulging of the bottom occurred (Example 2) In this embodiment, the loading device 20 is shown in FIGS.
This uses the device shown in Figure 1.

This transfers the preform P supplied from the preform supply machine 24 to the first or second branch machine 29a, 29b.
The device for selectively feeding the preforms has the following configuration: First and second branching machines 29a and 29b are connected to the preform supplying machine 24.

Then, an arc-shaped guide surface 105 is provided spanning the first and second branching machines 29a and 29b.

From this guide surface 105, the first and second branching machines 29a
, A rotating disk 106 with an outer edge protruding from the side 29b is rotatably provided.

A notch 107 for locking the preform is formed on the outer edge of the rotating disk 106.

Then, the preform locking notch 107 is aligned with the branching point 108 of the guide surface 105 (t
to attach the preform P to the preform locking notch 10.
7, and the preform P is configured to be transferred to either the first or second branching machine 29a, 29b along the guide surface 105 depending on the direction of rotation of the rotating disk 106. A notch 107 for locking eight preforms P as a conveying device for a molding machine.
When storing the preforms inside, there is a method in which the preforms P are allowed to fall naturally by tilting the preform supplying machine 24, or the preforms P are continuously transferred to the rotating disk 106 side using a belt conveyor or air pressure.

The preform locking notch 107 is connected to the guide surface 1.
At the position corresponding to the branch point 108 of 05, the preform P
is accommodated in the preform locking notch 107. In this state, when the rotary disk 106 is rotated, a force f moves the preform P in the direction of rotation, and at this time, the preform P has an arc-shaped guide surface spanning the first and second branching machines 29a and 29b. Move along 105.

When the rotary disk 106 further rotates, the preform P comes into contact with the guide surface 105 and reaches the straight portion of the first or second branching machine 29a, 29b, and is separated from the preform locking notch 107.

In this way, the preform P is supplied to the preform supply machine 2.
4 to the first or second branching machine 29a, 29b over the shortest distance, the distribution is performed at extremely high speed. Further, as the rotating disk 106 rotates, the preform P is transferred so as to be swung out along the arcuate guide surface 105, so that the preform P can be moved forward by inertia even after branching. can speed up the arrangement of

This will be explained in more detail below.

This device transfers the preform P supplied from the preform supplying machine 24 to the first or second branching machine 29a, 2.
9b. The preform P is conveyed from an injection molding machine (not shown) to the preform supplying machine 24 by a conveyor.

The preform supplying machine U and the first or second branching machines 29a and 29b are formed in a rail shape on which a flange P1 formed around the mouth of the preform P is placed on its upper surface. And the first and second branching gutter 29a
, 29b is supplied with a rotary disk 33,
The preform P made upside down by the rotary disk 33 is supplied to the rotating body 22 in an inverted state, and is sequentially transferred to the blow molding apparatus as described in the first embodiment.

The preform supply gutter 24 is approximately 3.
First and second branching troughs 29a and 29b are connected, which are inclined at an angle of 0 degrees and also inclined at an angle of about 30 degrees with respect to the horizontal plane.

These preform supply troughs, first and second branching troughs 29a, 29b are connected to each other with an angle difference of about 120 degrees on a horizontal plane. An arc-shaped guide surface 105 is provided at a portion spanning the preform supply gutter 24.
The end has a smooth curved surface. This allows the preform P to be transferred smoothly.

A rotating shaft 111 of a stepping motor 110 is arranged on an extension of the preform supply gutter 24, and a rotating disk 106 is attached to this rotating shaft 111. The outer edge of this rotating disk 106 is the guide surface 1
05 to cover the width of the first and second branching troughs 29a and 29b. Four notches 107 for locking the preform are provided on the outer edge of the rotary disk 106 at intervals of 90 degrees.

The width of this preform locking notch 107 is larger than the diameter of the preform P and smaller than the diameter of the flange portion P1. At the position coincident with point 108, the preform P is accommodated in the preform locking notch 107 by falling naturally.

A guardrail 111 is positioned close to the rotating disk 106 within a range of about 150 degrees.

This guardrail 111 is arranged at a position where the rotating disk 106 does not hang over the first and second branching troughs 29a and 29b.

These preform supply gutter, first and second branch gutter 29a, 29b, rotating disk 106, and stepping motor 110 are integrally attached to a frame 113 assembled with bolts 112. The guard plate 1 is attached to the frame 113 via the pole 115.
14 is provided. This guard plate 114 is a rotating disk 106.
It should be located above. Furthermore, a support arm 117 is attached to the frame 113 for supporting the first and second branching troughs 29a and 29b.

The frame 113 is fixed to the base via the main pole 116.

In the carrying-in device t20 having the above-mentioned configuration, a rotary disk 33 is connected to the tips of the first and second branching troughs 29a and 29b, respectively. This rotary disk 33 is used to turn the carried preform P upside down. A rotary body 22 is disposed at the tip of these rotary disks 33, and a preform holding portion 42 is provided around the rotary body 22.

The preform P, which has been turned upside down on the rotary disk 33, is held in the preform holding section 42 and transported to the next step.

In the above embodiment, the preform locking notches 107 are provided at four locations at 90-degree intervals on the outer edge of the rotating disk 106. . However, if it is necessary to feed the preform at the first vehicle position, the next preform P is fed after the previously fed preform P is completely separated from the preform locking notch 107. Since it is necessary to lock the preform locking notch 107, there is a limit to the number of preform locking notches 107 that can be formed.

Further, the step angle of the stepping motor 110 is 3
It is desirable to set the angle to be 60 degrees divided by the number of preform locking notches 107.

The operation will be explained below.

The stepping motor 110 is operated to move the preform locking notch 107 to the branch point 1 of the guide surface 105.
08, the preform P is accommodated in the preform locking notch 107.

In this state, when the rotary disk 106 is rotated as shown in FIG. 5, the preform P moves in the direction of rotation.

At this time, the preform P is connected to the first and second branching troughs 29.
a and 29b along an arcuate guide surface 105. When the rotary disk 106 further rotates, the preform P comes into contact with the guide surface 105 and reaches the straight portion of the first or second branching gutter 29a, 29b, and is separated from the preform locking notch 107.

In this way, the preform P is transferred to the preform supply gutter 2.
4 to the first or second branching gutter 29a, 29b over the shortest distance, the distribution can be speeded up.

Further, as the rotating disk 106 rotates, the preform P
Since it is swung out along the arc-shaped guide surface 105, the next operation of the stepping motor 110 can be performed immediately, and redundant time can be saved. Furthermore, the momentum of this swing allows the preforms P to advance within the gutter even after branching, and the effect of speeding up the arrangement of the preforms P can be expected.

In addition, if preforms are accumulated in only one branching gutter, the sensor installed in the branching gutter will detect this and
It is preferable to control the direction of rotation of the rotary disk 6 so that the preform is supplied only to the other branching gutter.

With the above configuration, the preform P is placed between the first or second branching gutter 29 depending on the rotational direction of the rotating disk 106.
a, 29b. Also, the rotating disk 106 is continuously rotated in one direction.i! , the preform P can be continuously transferred at high speed only to a specific branching gutter.

〔Effect of the invention〕

According to the present invention, two-stage blow molding can be performed automatically and efficiently. Since it is a two-stage blow, it is possible to mold containers with a high degree of molecular orientation and good gas barrier properties, and it is also possible to easily mold molded products with a high heat resistance temperature.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an example of the device of the present invention; Fig. 2 is a plan view showing a part of the loading device; Fig. 3 is a front view thereof; Fig. 4 is a plan view showing another part of the loading device. The plane is shown in Figure 5. Figure 6 is the cross section of the core metal. Figure 7 is the front cross section of the loading rotor. Figure 8 is the partially crushed plane. Figure 9 is the first rotor. Figure 10 shows a front cross section A of the second core holder attached to the first rotating body.
Fig. 11 is a diagram of the first rotating body part in the preform delivery section, and shows the operation of the second core metal holder in that part. Figure 14 is a plane showing the preform delivery to the blow molding machine. Figure 14 is a cross-sectional view of the core with the core installed, partially showing the blow molding mold. Figure 15 is the core showing the secondary blow molding mold. Cross section 1 in installed state FIG. 16 is a plan view showing the core exchange device near the carry-in/out device. Figure 17-2
Figure 1 shows another embodiment of the present invention. Figure 17 shows the plane of the main part. Figure 18 shows the side view of the main part. Figure 19 shows the plane of the entire attached device. Figure 20 shows the side view. The figure is a plan view of main parts for explaining the operation. 1 First rotating book 2 ・Primary heating device, 3...
Secondary heating device, 5... Loading/unloading device, 7... Secondary blow molding machine, P... Preform, 21... Base, 45... First core metal holder, 70... No. 3-turn main 71... Mold for primary blow molding, 78... Mold for secondary blow molding 4... Heating tower, 6... Primary blow molding ring 8... Core metal, 20... Carrying device 22...Second rotating body 60...Second core metal holder

Claims (1)

[Claims] (1) The core metal 8 circulates from the carry-in/out device 5 to the carry-in/out device 5 via the primary heating device 2, primary blow molding machine 6, secondary heating device 3, and secondary blow molding machine 7. Device 5
A cylindrical synthetic resin preform P with a bottom is placed at the receiving position of
is held, and this preform P is heated in the primary heating device 2.
After being heated in It is a two-stage stretch blow molding device that performs stretch blow molding on the final molded product, and then removes and takes out the final molded product from the core metal 8 at the time of returning to the loading/unloading device 5, the loading/unloading device 5, the primary heating device. 2. The primary blow molding machine 6, the secondary heating device 3, and the secondary blow molding machine 7 are provided along the circumference of the first rotating body 1, and the carrying-in/out device 5 is provided along the circumference of the first rotating body 1.
The second rotating body 22 has a plurality of first core metal holders 45 surrounding it that hold the core metal 8, and the core metal 8 holding the preform P is held in the first core metal holder. 45 to the first rotating body 1, and the first rotating body 1 has a second rotating body around which the core bar 8 is held.
The primary blow molding machine 6 has a large number of core metal holders 60, and receives the core metal 8 holding the preform P from the second core metal holder 60 of the first rotating body 1, and then internalizes the preform P. A large number of primary blow molding molds 71 are provided around the third rotating body 70,
The primary blow molding die 71 is used to perform stretch blow molding into a pre-stretched product, and the core bar 8 is transferred together with the pre-stretched product to the second core holder 60 of the first rotating body 1, and the secondary blow molding is carried out. The molding machine 7 receives the core bar 8 holding the pre-stretched product that has passed through the secondary heating device 3 and is heated and shrunk, and then inserts a secondary blow-molding mold 78 in which the pre-stretched product is placed inside. The secondary blow molding mold 78 is used to perform stretch blow molding into the final molded product, and the core bar 8 is transferred together with the final molded product to the loading/unloading device 5.
A two-stage stretch blow molding device configured to transfer the material to the second rotating body 22 of the machine.