JPS6130896B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection stretch blow molding method for manufacturing hollow containers using synthetic resin materials such as polyethylene terephthalate and polypropylene, and an apparatus for carrying out this method.

A conventional injection stretch blow molding apparatus is disclosed in, for example, Japanese Patent Application Laid-Open No. 57-93125. This injection stretch blow molding apparatus has a parison injection molding section, a parison temperature adjustment section, a parison stretch blow molding section, and a blow molded product releasing section arranged in line.
The neck molds arranged in each of these parts are sequentially and simultaneously linearly moved from the parison injection molding part to the hollow molded product release part, and when each neck mold stops, the molded product and mold release are performed in each part, and the hollow After the molded product has been released, the neck mold is circulated to the parison injection molding section during the molding time to prepare for the next molding.

However, in the conventional injection stretch blow molding apparatus as described above, it is necessary to circulate the neck mold, so the apparatus for carrying out this method becomes large-sized, and it takes time to install the apparatus. It required a relatively large space. Also,
A neck mold was required for each of the parison injection molding section, parison temperature adjustment section, parison stretch blow molding section, and hollow molded product release section, which required expensive neck molds with strict dimensional accuracy and high material hardness. A large number of molds are required, and if the shape of the network mold is changed, a large amount of cost is required. In addition, among the operations of parison injection molding, parison temperature adjustment, parison stretch blow molding, and blow molded product release, parison temperature adjustment required the longest time, so the cycle time of this injection stretch blow blow molding equipment was The time is regulated by the parison temperature adjustment time, making it difficult to improve the molding speed.

The present invention has been made by focusing on the above-mentioned problems in conventional injection stretch blow molding equipment, and the neck mold is moved by a gripper device that reciprocates the parison to form an injection mold. The purpose of the present invention is to solve the above-mentioned problems by providing a plurality of parison temperature adjustment sections.

Hereinafter, the present invention will be explained based on FIGS. 1 to 3 of the accompanying drawings.

The injection stretch blow molding apparatus according to the present invention includes an injection section 2, a mold clamping section 4, a first parison temperature control section 6, a second parison temperature control section 8, and a parison stretch blow molding section arranged in a straight line on a bed 1. 10 and a hollow molded product discharge section 12. An injection device 14 is installed in the injection section 2. The mold clamping section 4 includes a mold clamping device 16 and a neck mold 69 attached to the mold clamping device 16.
It has an upper injection mold 18 and a lower injection mold 20. The injection device 14 is capable of injecting molten resin into the lower injection mold 20 . The first parison temperature adjustment section 6 is provided with a movable parison temperature adjustment cylinder 22 . The movable parison temperature control tube 22 is installed so as to be movable in the horizontal direction on the running path 24, and is reciprocated between the first parison temperature control section 6 and the mold clamping section 4 by the action of the air cylinder 26. can do. A fixed parison temperature control tube 28 is fixed to the second parison temperature control section 8 . A blow mold 30 is installed in the parison stretch blow molding section 10 . Note that the blow mold 30 can be opened and closed to the left and right by known means. Further, the hollow molded product discharge section 12 is provided with a discharge hole 34 formed in a horizontal plate 32 that partitions the inside and outside of the device and serves as a safety cover. Note that the distance between the movable parison temperature control tube 22 stopped at the first parison temperature control section 6 and the fixed parison temperature control tube 28, the distance between the fixed parison temperature control tube 28 and the blowing mold 30, and the blowing Mold 30 and discharge hole 3
All distances to 4 are set as constant distances. Above the first parison temperature control section 6, the second parison temperature control section 8, the parison stretch blow molding section 10, and the hollow molded product discharge section 12, there is a horizontal frame supported with respect to the bed 1 by struts 36. 38 are provided. The frame 38 has a running path 4 on its upper part.
0, and a temperature control gripper moving table 42, a stretch blow molding gripper moving table 44, and a discharging gripper moving table 46 are arranged horizontally movably on this running path 40. The temperature adjustment gripper moving table 42, the stretch blow molding gripper moving table 44, and the discharge gripper moving table 46 are connected by a connecting rod 47 so as to move together.
They simultaneously reciprocate by the action of the air cylinder 48. The temperature adjustment gripper moving table 42 has a temperature adjustment gripper device 52 that can be moved up and down by an air cylinder 50. Temperature regulating gripper device 52 is capable of gripping parison 68 .
Similarly, the ejection gripper moving table 46 is movable up and down by the air cylinder 54.
6. The ejecting gripper device 56 is capable of gripping the hollow molded product 70 . The gripper moving table 44 for stretch blow molding is a gripper device 60 for stretch blow molding that can be moved up and down by a hydraulic cylinder 58.
have. This gripper device 60 for stretch blow molding is capable of gripping a parison 68 and has a stretching rod 6 that can be moved up and down by a blow pipe 62 for blowing air into the parison 68 and a hydraulic cylinder 64.
It is equipped with 6. Grip device 52, 56 and 6
0 will not be described in detail, but each of them has a built-in means for opening and closing the pawls, and can grip the parison neck portion and the hollow molded product neck portion. In addition, the temperature control gripper device 52
The distance between the gripper device 60 for stretch blow molding and the distance between the gripper device 60 for stretch blow molding and the gripper device 56 for ejection are the same as the distance between the movable parison temperature control tube 2 stopped at the first parison temperature control section 6.
2 and the fixed parison temperature control tube 28, etc., as described above.

Next, the operation of the above device will be explained.

First, the upper injection mold 18 and the lower injection mold 20 having the neck mold 69 are clamped by the mold clamping device 16, the nozzle of the injection device 14 is brought into contact with the lower injection mold 20, and the molten resin is extruded into the parison. 68 is molded. When the molding is completed, the upper injection mold 18 is raised, and the molded parison 68 is held in the neck mold 69 and raised with respect to the upper injection mold 18. At the same time, the movable parison temperature control cylinder 22 is moved below the upper injection mold 18 by the action of the air cylinder 26. The molded parison 68 is a neck mold 69
After the injection mold 18 is opened, the injection mold 18 is opened by known means.
The mold is released from the mold and housed in the moving parison temperature control cylinder 22. The movable parison temperature adjustment tube 22 immediately starts temperature adjustment of the parison 68 and moves from the mold clamping section 4 to the first parison temperature adjustment section 6. The state after the movement is shown in the first parison temperature control section 6 in FIG. Next, the parison 68 is lifted up by the temperature adjusting gripper device 52 which has been lowered by the operation of the air cylinder 50 and is gripped by the neck portion. Next, the temperature adjustment gripper moving table 42 is moved to the left in FIG. 1 by the operation of the air cylinder 48, and the parison 68 is carried above the second parison temperature adjustment section 8. The temperature regulating gripper device 52 then lowers and the parison 68
is housed within the fixed parison temperature control tube 28.
This state is shown in the second parison temperature control section 8 in FIG. Temperature adjustment of the parison 68 continues within the fixed parison temperature adjustment cylinder 28. During this time, the temperature adjusting gripper moving table 42, the stretch blow molding gripper moving table 44, and the discharging gripper moving table 46 return to the state shown in FIG. 1 again. When the temperature adjustment of the parison 68 is completed, the gripper device 60 for stretch blow molding is lowered by the operation of the hydraulic cylinder 58, grips the parison 68 in the fixed parison temperature adjustment cylinder 28, and lifts it up. Next, the stretch blow molding gripper moving table 44 moves to the left in FIG. 1 and reaches above the parison stretch blow molding section 10. When the gripper moving table 44 for stretch blow molding reaches above the parison stretch blow molding section 10, the gripper device 60 for stretch blow molding descends and grips the parison 68.
is housed in the blow mold 30. Next, the stretching rod 66 is extended into the parison 68 by the operation of the hydraulic cylinder 64, and stretched downward while holding the core at the bottom of the parison so that it does not swing.Furthermore, in parallel with this, compressed air is sent in from the blowing pipe 62. It also stretches in the lateral direction. Stretch blow blow molding is thereby performed, and the hollow molded product 70 is formed. This state is shown in the parison stretch blow molding section 10 in FIG.
When the molding is completed, the gripper device 60 for stretch blow molding rises, moves to the right, and returns to the state shown in FIG. 1. Next, the ejection gripper device 56 is lowered by the operation of the air cylinder 54 and the hollow molded product 7 is lowered.
Grab the 0 neck part. Next, the blow mold 30 is opened and the hollow molded product 70 is transferred to the ejection gripper device 5.
lifted by 6. The lifted hollow molded product 70 reaches the upper part of the hollow molded product discharge section 12 by moving the discharge gripper moving table 46 to the left. Then, the ejecting gripper device 56 descends and ejects the hollow molded product 70 from the ejecting hole 34.
This state is shown in the hollow molded product discharge section 12 in FIG. This completes the molding of one hollow molded product 70.

Note that the above explanation has focused on one parison 68 and the hollow molded product 70, but the mold clamping section 4, the first parison temperature adjustment section 6, and the second
Operations in the parison temperature control section 8, parison stretch blow molding section 10, and hollow molded product discharge section 12 are performed in parallel and continuously. That is, after the upper injection mold 18 and the lower injection mold 20 are clamped to perform parison molding, and until the parison 68 is taken out as shown in the first parison temperature control section 6 in FIG. The conditioning gripper device 52, the stretch blow molding gripper device 60, and the ejection gripper device 56 perform one cycle as follows.
That is, the temperature regulating gripper device 52 and the stretch blow molding gripper device 60 first descend from the initial positions shown in FIG. 1 and stand by while gripping the parison 68, respectively. On the other hand, at this time, the discharge gripper device 56 is in the raised position where it grips and lifts the hollow molded product 70 after molding. In this state, the parison 6 inside the fixed parison temperature control cylinder 28
8, the gripper device 60 for stretch blow molding is raised, and at the same time, the gripper device 52 for temperature adjustment is also raised while gripping the parison 68. In this way, the temperature regulating gripper device 5
2. When the gripper device 60 for stretch blow molding and the gripper device for ejection are all in the raised state, the temperature adjustment gripper moving table 42, the gripper moving table 44 for stretch blow molding, and the gripper moving table for ejecting 46
is moved to the left. By doing this, the temperature regulating gripper device 52 reaches the upper part of the second parison temperature regulating section 8, the stretch blow molding gripper device 60 reaches the upper part of the parison stretch blow molding section 10, and the ejecting gripper device 52 reaches the upper part of the parison stretch blow molding section 10. 56 reaches the upper part of the hollow molded product discharge section 12. When the movement to the left is completed, the temperature control gripper device 5
2. The stretch blow molding gripper device 60 and the discharge gripper device 56 are lowered simultaneously. The temperature regulating gripper device 52 stands by with the parison 68 inserted into the fixed parison temperature regulating tube 28. Further, after the discharge gripper device 56 discharges the hollow molded product 70 from the discharge hole 34, when the molding of the hollow molded product 70 in the blow mold 30 that is raised and stands by is completed, the temperature adjustment gripper device 52 and the stretching The blow molding gripper device 60 ascends while leaving the parison 68 and the hollow molded product 70 in the fixed parison temperature control tube 28 and the blow mold 30, respectively. When the temperature regulating gripper device 52, the stretch blow molding gripper device 60, and the discharge gripper device 56 are all in the raised state, they are moved to the right by the operation of the air cylinder 48, and are shown in FIG. Returns to the initial position shown. This completes one cycle of parison temperature adjustment, parison stretch blow molding, and hollow molded product discharge.
While this one cycle is being executed, the parison 68 is molded in the mold clamping section 4, and the parison 68 is taken out to the first parison temperature control section 6. Next, each operation is executed continuously by repeating the same process again.

In the injection stretch blow molding apparatus according to the present invention as described above, the neck mold 69 that forms the neck part of the parison 68 is provided only in the mold clamping part 4, and there is no need to circulate and move the neck mold 69. , it is possible to downsize the device and reduce the installation area. In addition, the expensive neck mold 69 has a mold clamping part 4.
Even if the shape of the parison is changed, it is only necessary to replace the neck mold 69 of the mold clamping part 4, so the cost is relatively low.
In addition, a plurality of parison temperature control tubes (a moving parison temperature control tube 22 and a fixed parison temperature control tube 2) are provided.
8), it is possible to shorten the parison temperature adjustment time in each parison temperature adjustment cylinder, thereby shortening the time required for the entire molding cycle and improving efficiency.

In the described embodiment, one stage of fixed parison temperature control tubes 28 is provided, but two or more stages may be provided as necessary. Further, in the described embodiment, two parisons are passed in parallel, but the number of parisons can be set arbitrarily. Further, if heat treatment of the blow molded product is required, a molded product heat treatment section can be provided between the parison stretch blow molding section 10 and the blow molded product discharge section 12.

As explained above, according to the present invention, the injection stretch blow blow molding method for molding a hollow container using a synthetic resin material molds a parison in an injection mold attached to a mold clamping device. The parison is removed from the injection mold and the parison temperature is controlled by a movable parison temperature control tube that can be moved between the inside and outside of the parison, and the parison is taken out from the movable parison temperature control tube and placed into the fixed parison temperature control tube. At least the second parison temperature adjustment is carried out by storing the parison once or by sequentially storing it in a plurality of fixed parison temperature control tubes, and the parison is removed from the fixed parison temperature control cylinder after the parison temperature control has been completed. Place it in a blow mold, extend the stretching rod into the parison, and blow compressed air to perform stretch blow molding to form a hollow molded product.The hollow molded product is taken out from the blow mold and discharged. It consists of the above-mentioned steps of transferring the parison to the fixed parison temperature control tube, moving the parison from the movable parison temperature control tube to the fixed parison temperature control tube, and if there are multiple fixed parison temperature control tubes, moving the parison between the fixed parison temperature control tubes, etc. The movement of the parison, the movement of the parison from the fixed parison temperature control tube to the blowing mold, and the movement of the hollow molded product from the blowing mold to the hollow molded product discharge section were arranged in alignment so as to reciprocate simultaneously. The process is carried out by each gripper device, and the time required for one cycle of each gripper device is less than or equal to the time required to form a parison in an injection mold and remove it by a moving parison temperature control cylinder. Therefore, the apparatus for carrying out the above method includes an injection device capable of injecting molten resin, a mold clamping device to which an upper injection mold and a lower injection mold for parison molding are attached, which receive the molten resin from the injection device. A movable parison temperature control tube movable between the inside and outside of the mold clamping device, and one parison temperature control disposed at a fixed distance from a stopping position of the movable parison temperature control tube outside the mold clamping device. a plurality of fixed parison temperature control tubes arranged in sequence and spaced apart from each other by the fixed distance; A blow mold arranged at a certain distance apart, a movable parison temperature control cylinder, a fixed parison temperature control cylinder, and a hollow mold arranged in alignment with the blow mold and separated from the blow mold by the certain distance. A gripper device for temperature adjustment that is movable between a product discharge section, a stop position outside the mold clamping device of the movable parison temperature adjustment tube, and the fixed parison temperature adjustment tube and capable of gripping the parison, and a fixed parison temperature adjustment tube. If there are multiple fixed parison temperature control tubes, a temperature control gripper device that can move between each fixed parison temperature control tube and can grip the parison is used, and a temperature control gripper device that can move between the fixed parison temperature control tube and the blowing mold and that can grip the parison. A gripper device for stretch blow molding comprising a blow tube which is grippable and blows air into the parison and an extendable stretching rod, and a gripper device which is movable between the blow mold and the hollow molded product discharge part and which is hollow. It is characterized by having a discharge gripper device capable of gripping a molded product, and a mechanism for simultaneously moving the temperature adjustment gripper device, the stretch blow molding gripper device, and the discharge gripper device in the horizontal direction, so that the installation area of the device is reduced. The following effects can be obtained: reduction in mold manufacturing costs, and improvement in molding speed.

[Brief explanation of the drawing]

FIG. 1 is a front cross-sectional view of an injection stretch blow blow molding apparatus according to the present invention (showing the state at the start of the cycle);
Fig. 2 is a sectional view taken along the - line of the injection stretch blow molding apparatus shown in Fig. 1, and Fig. 3 shows the state of the injection stretch blow blow molding apparatus shown in Fig. 1 during injection molding and stretch blow molding. FIG. 1... Bed, 2... Injection part, 4... Mold clamping part,
6... First parison temperature control section, 8... Second parison temperature control section, 10... Parison stretch blow molding section, 12... Hollow molded product discharge section, 14... Injection device, 16... Mold clamping device , 18... Injection upper mold, 2
0... lower injection mold, 22... parison temperature control tube, 24... running path, 26... air cylinder, 2
8...Parison temperature control cylinder, 30...Blowing mold,
32... Horizontal plate, 34... Discharge hole, 36... Support, 38... Frame, 40... Running path, 42...
...Gripper moving base for temperature adjustment, 44...Gripper moving base for stretch blow molding, 46...Gripper moving base for ejection, 47...Connecting rod, 48...Air cylinder, 50...Air cylinder, 52...Temperature Adjustment gripper device, 54...Air cylinder, 56...
Discharging gripper device, 58... Hydraulic cylinder, 6
0...Gripper device for stretch blow molding, 62...Blow pipe, 64...Hydraulic cylinder, 66...Stretch rod, 68...Parison, 69...Neck type.

Claims (1)

[Claims] 1. In an injection stretch blow blow molding device for molding hollow containers using synthetic resin as a material, a parison is molded in an injection mold attached to a mold clamping device, and the inside and outside of the mold clamping device are The parison is removed from the injection mold and the parison temperature is controlled by a movable parison temperature control tube that can be moved between At least the second parison temperature adjustment is carried out by or by sequentially storing the parison in a plurality of fixed parison temperature adjustment cylinders, and the parison is taken out from the fixed parison temperature adjustment cylinder after the parison temperature adjustment is completed and stored in a blowing mold. The process consists of each of the above-mentioned processes, in which a blow molded product is formed by blowing compressed air while stretching it with a stretching rod, performing stretch blow blow molding, and then taking out the hollow molded product from the blow mold and transporting it to the hollow molded product discharge section. Transfer of the parison from the movable parison temperature control tube to the fixed parison temperature control tube, movement of the parison between each fixed parison temperature control tube if there are multiple fixed parison temperature control tubes, and blowing from the fixed parison temperature control tube. The movement of the parison into the mold and the movement of the hollow molded product from the blowing mold to the hollow molded product discharge section are performed by respective gripper devices arranged in an array so as to reciprocate horizontally at the same time. , the time required for one cycle of each gripper device is less than or equal to the time required to form the parison in the injection mold and remove it by the moving parison temperature control tube;
An injection stretch blow molding method characterized by: 2. An injection device capable of injecting molten resin, a mold clamping device to which an upper injection mold and a lower injection mold for parison molding that receive the molten resin from the injection device are attached, and between the inside and outside of the mold clamping device a movable parison temperature control tube, and one parison temperature control tube arranged a fixed distance apart from a stopping position outside the mold clamping device of the movable parison temperature control tube, or one parison temperature control tube successively separated from each other by the fixed distance. a plurality of fixed parison temperature control tubes arranged in line; and a blowing metal arranged in alignment with the movable parison temperature control tube and the fixed parison temperature control tube and spaced from the fixed parison temperature control tube by the predetermined distance. a mold; a hollow molded product discharge section arranged in line with the movable parison temperature control tube, the fixed parison temperature control tube, and the blow mold and spaced from the blow mold by the predetermined distance; the movable parison temperature control tube A gripper device for temperature adjustment that is movable between a stop position outside the mold clamping device and a fixed parison temperature adjustment cylinder and that can grip the parison, and when there are multiple fixed parison temperature adjustment cylinders,
a temperature regulating gripper device movable between each fixed parison temperature regulating tube and capable of gripping the parison; and a temperature regulating gripper device movable between the fixed parison temperature regulating tube and the blow mold and capable of grasping the parison; a gripper device for stretch blow molding equipped with a blow tube for blowing air into the mold and an extendable stretching rod; An injection stretch blow molding apparatus comprising: a gripper apparatus for temperature adjustment, a gripper apparatus for stretch blow molding, and a gripper apparatus for discharging at the same time in a horizontal direction.