JPH0532211B2 - - Google Patents

Description

[Detailed description of the invention]

【0001】

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary injection stretch blow molding machine that can continuously perform injection molding of preforms and stretch blow molding of molded products such as bottles and containers.

【0002】

BACKGROUND ART As a molding machine of this type, a molding machine described in Japanese Patent Publication No. 53-22096 is generally known. This molding machine was developed by the inventor, and the lower base on the machine stand and the upper base above it are integrally connected by tie rods at the periphery, and the preform is formed between the two bases. It is constructed so that operations such as injection molding, temperature control, stretch blow molding, and molded product removal can be performed in sequence.

[0003] In addition, the injection core and blowing core devices, drive devices, etc. are installed on the upper side of the upper base, and a rotary plate with a net type on the lower side that also serves as a holding type is provided on the lower side of the upper base, and the rotary plate The structure is such that preforms injection-molded into a neck mold and molded products subjected to stretch-blow molding can be transferred using the holder.

【0004】

[Problems to be Solved by the Invention] In such a molding machine, the lower base and the upper base are in a fixed state, so the interval between the two bases cannot be changed according to the height dimension of the molded product. Even if the spacing is allowed, there is a molding restriction on the height dimension, which not only lacks versatility, but also has the drawback of having to raise the height of the injection and blowing cavity molds when molding small bottles etc. It was hot.

[0005] Also, since the injection cavity mold side is moved up and down relative to the neck mold on the upper base plate side to open and close the mold, the injection device can be placed with the nozzle touching the injection cavity mold or hot runner block at all times. First, it is necessary to touch the nozzle each time the mold is opened and closed, and to take measures to prevent resin from leaking from the nozzle.

[0006] Furthermore, since the injection cavity mold is pressed against the upper base from below to clamp the neck mold and the injection cavity mold, the clamping force is concentrated in the center of the upper base. The rotary disk is susceptible to deflection along with the upper base, and since the injection cavity mold is connected to the upper end of the mold clamping ram, the injection cavity mold is likely to sway laterally when the mold is closed due to the lateral pressure when the nozzle is touched. Due to this, it also has the disadvantage that uneven thickness tends to occur in the preform.

[0007] In addition, when transferred by a rotary disk, the preform and molded product draw a circular trajectory, whereas the blow cavity mold of the lower base is provided parallel to the tangent to the circular trajectory and can be opened and closed in the radial direction. Therefore, unless the mold is opened significantly larger than the diameter of the molded product, there are many problems such as the molded product hitting the end of the blow cavity mold during rotational transfer and being damaged.

[0008] This invention was devised to solve the above-mentioned conventional problems, and its purpose is to be able to change the height of the transfer plate together with the lifting plate according to the height dimension of the molded product, and to improve the injection cavity. It is an object of the present invention to provide a new injection stretch blow molding machine in which a mold can be installed on a base and an injection nozzle can be touched at all times, and furthermore, the bending of an elevating plate and a transfer plate due to mold clamping force can be prevented.

[0009]

[Means for Solving the Problems] The feature of the present invention according to the above object is that a support plate is provided above a base fixed on a machine base and connected by a plurality of tie rods, and a gap between the support plate and the base is provided. The lifting plate and the mold clamping plate on the upper part of the lifting plate are inserted into the tie rods so as to be able to move up and down, and a circular shape is inserted under the lifting plate which rotates intermittently at 120 degree intervals by a drive device installed at the center of the upper side of the lifting plate. A transfer plate is provided, and holding molds that can be opened and closed in the radial direction are attached to three sides of the lower surface of the transfer plate.
The stopping position of the holding mold is used as an injection operation section, a stretching blowing operation section, and an ejection operation section, and an injection cavity mold and a blowing cavity mold for closing the holding mold and the mold are installed on a base, and the injection cavity A mold clamping device is provided on a support plate above the mold by connecting a mold clamping ram to the mold clamping plate, and the injection cavity is passed through the holding mold through openings formed in the lifting plate and the transfer plate. An injection core that closes the mold is attached to the lower side of the mold clamping plate, and an elevating device using a cylinder and piston rod that moves the elevating plate up and down together with the transfer plate is provided between the base and the elevating plate. It is in.

[0010]

[Function] In this invention having the above structure, when the piston rod of the elevating device is reduced, the elevating plate descends together with the transfer plate, and the injection cavity mold and the holding mold are closed. Conversely, when the piston rod extends, the elevating plate lowers together with the transfer plate. is raised together with the transfer plate and returned to its original position, and the injection cavity mold and holding mold are opened.

[0011] Therefore, after injection molding of the preform, the piston rod of the elevating device is extended while the mold clamping ram is reduced, and the injection cavity mold, the injection core, and the holding mold are opened by returning the elevating plate. The return position is maintained by the lifting device, and the preform and the molded product can be rotated and transferred by the transfer plate.

[0012] In addition, the mold clamping force from above in the injection operation section is received by the base, and the lifting plate and transfer plate that are narrowed between the mold clamping plate and the injection cavity mold are free in the vertical direction. Since the mold is in this state, the mold clamping force is not concentrated in the central portion, causing no deflection, and uneven thickness of the preform, which is caused by deflection, does not occur.

[0013]

[Embodiment] In the figure, 1 is a machine stand, and a base 2 is fixed to the upper part. Above the base 2, a support plate 3 is connected to the base 2 by tie rods 4, 4 at three points on the periphery.
It is connected to and located horizontally.

[0014] Also, between the base 2 and the support plate 3, an elevating plate 5 and a mold clamping plate 6 are provided, and an ear piece 5 bored at the edge is provided.
a, 6a are slidably inserted into the tie rods 4, 4, and are provided horizontally so that they can be raised and lowered and moved toward and away from each other.

[0015] On the lower side of the elevator board 5, there is a circular transfer board 8 that rotates intermittently at 120 degree intervals by a hydraulic or electric drive device 7 fixed to the upper center of the elevator board 5. The sides are held by members 9 and rotatably attached by a shaft 10 in the center.

[0016] A pair of split molds 11 are attached to three sides of the lower surface of the transfer plate 8 so as to be openable and closable in the radial direction.
There is a holding mold 12 which also serves as a neck type, and the stopping position of this holding mold 12 is as shown in FIG.
They can be used as an injection operation section A, a stretch blow operation section B, and an ejection operation section C, respectively.

[0017] On the base 2 corresponding to the injection operation part A,
An injection cavity mold 13 is installed. This injection cavity mold 13 is mounted and fixed on a base 14 fixed to the upper surface of a base plate by a pin 14c via a spring member 14a.

[0018] Also, inside the pedestal 14, a hot runner block 16 is fixedly provided to the base 2, and an injection device 15 constantly touches a sprue gate of the hot runner block 16 with its nozzle.

[0019] Between the tip of the nozzle 16a of the hot runner block 16 and the cavity gate 13a of the injection cavity mold 13, there is a gap between the bottom of the base and the top surface of the base created by the spring member 14a.
14b, and when the spring member 14a is compressed by pressure from above and the base 14 bottoms out on the top surface of the base, the tip of the nozzle 16a touches the cavity gate 13a.

[0020] At a corresponding position above the injection cavity mold 13, a hydraulically operated mold clamping device 18 is installed to lock the cylinder 1.
8a is connected to the support plate 3, and a mold clamping ram 19 is connected to the mold clamping plate 6, and from the openings 5b and 8a bored in the lifting plate 5 and the transfer plate 8 below the mold clamping plate 6,
An injection core 17 that closes the holding mold 12 and the injection cavity mold 13 is mounted facing downward.

[0021] Base 2 corresponding to the stretch blow molding section B
At the top, a blow cavity mold 20 is connected to a piston rod 22 of a hydraulically operated opening/closing device 21, and is installed so as to be freely openable and closable in the radial direction.

[0022] Further, above the blowing cavity mold 20, an opening 5b formed in the elevator plate 5 and the transfer plate 8,
From 8a, the holding mold 12 and the blowing cavity mold 2
A blowing core 23 that closes the mold with 0 is fixedly attached to the lower side of the mold clamping plate 6.

[0023] Furthermore, an expansion device 25 of a rod 24 is installed above the mold clamping board 6 and extends through the mold clamping board 6 and the blowing core 23 to the inside of the blowing cavity mold 20. The extension rod 24 is connected to the lower end of the piston rod 26 which is actuated by the piston rod 26.

[0024] As shown in FIG. 5, the base 2 corresponding to the take-out operation section C has a molded product guide hole 27, and the mold clamping plate 6 corresponds to the guide hole 27.
A take-out device 28 is attached to the upper side.

[0025] This take-out device 28 consists of a pair of wedge-shaped mold opening plates 30 attached to the lower end of a piston rod 29 operated by air, and the mold opening plates 30 penetrate the mold clamping plate 6 and the lifting plate 5. Then, the split mold 11 of the holding mold 12 is pushed open in the radial direction, and the molded product whose opening portion is held between the holding mold 12 is released.

[0026] Reference numeral 31 denotes an air or hydraulically operated lifting device, in which a cylinder 31a is placed on the board surface of the base 2, a piston rod 31b is connected to a rotating member 7a in the center of the transfer board 8, and the base 2 and the elevator board are connected. 5.

[0027] The lifting position of the lifting plate 5 by this lifting device 31 is limited by the extension length of the piston rod 31b, but by adjusting the length, the height position of the lifting plate 5 can be adjusted according to the height dimension of the molded product. It can be set arbitrarily according to the setting position, and by maintaining the elevator plate 5 together with the transfer plate 8 at the set position, the preform 40 and the molded product 41 can be transferred by rotation of the transfer plate 8.

[0028] In the illustrated example, the elevating device 31 is provided at the center, but it may be provided at the periphery of the elevating board 5. In this case, a plurality of elevating devices may be arranged in a well-balanced manner. become.

[0029] In the above embodiment, in the mold clamping state shown in FIG. 2, the preform 40 and the bottle-shaped molded product 4
When the molding of step 1 is completed and the next step is to open the mold, the mold clamping force by the mold clamping device 18 is first removed;
The mold clamping rod 19 returns to its original position due to hydraulic pressure.

[0030] In addition, in the lifting device 31, the piston rod 31b is extended by hydraulic pressure or the like, and the lifting plate 5
At the same time, the transfer board 8 is raised and returned. This results in Figure 2
As shown in FIG. 2, in the injection molding operation section A, the injection core 17, the holding mold 12, and the injection cavity mold 13 are opened, and the preform 40 is inserted into the holding mold 1.
2 holds the neck part and the injection cavity mold 13
And the mold is released from the injection core 17.

[0031] As the mold clamping force is released, on the injection cavity mold side, the pedestal 14 moves away from the top surface of the base plate to the position restricted by the pin 14c due to the repulsive force of the spring member 14a, and thereby the hot runner block 16
The nozzle tip also moves away from the cavity gate 13a, and the nozzle touch is released.

[0032] In the stretch blowing operation section B, the blowing cavity mold 20 is opened, and the molded product 41 is released from the mold by moving the blowing core 23 and the holding mold 12 upward.

[0033] As shown in FIG. 1, when the mold opening is completed, the driving device 7 rotates the transfer plate 8 by 120 degrees while the lifting device 31 maintains the lifting plate 5 at its set height position. The preform 40 is then transferred to the stretch blowing operation section B, and the molded product 41 is transferred to the takeout operation section C.

[0034] After stopping, the lifting device 31 switches to a contraction operation of the piston rod 31b, and the mold clamping device 18 switches to a mold clamping operation, so that the mold clamping plate 6, the lifting plate 6, and the transfer plate 8 are lowered. , as shown in FIG. 1, in the injection operation section A, an injection cavity mold 13,
The holding mold 12 and the injection core 17 are closed.

[0035] Although not shown in the drawing, in the stretch blowing operation section B, the preform is first located at the center of the blowing mold 20 in the mold open state, and in that state, the blowing mold 2 is opened.
0 is closed by the opening/closing device 21, and the holding mold 1
2 and the blowing core 23 are closed.

[0036] Furthermore, a mold clamping force is applied by the mold clamping device 18 to perform injection molding of a preform 40 in the injection operation section, and stretch blow molding of a bottle-shaped molded product 41 is performed in the stretch blow operation section B. Retrieval operation part C
Then, as shown in FIG. 5, the take-out device 29 is activated to push the mold opening plate 30 into the parting line of the holding mold 12, to push open the split mold 11 in the radial direction, and to release the molded product 41 into the holding mold. Remove from mold 12.

[0037] When the molding and unloading in each operating section are completed, the process switches again to mold opening, and the lifting plate 5 and mold clamping ram 19 are returned to their original positions.

[0038] For this reason, preform 4
The process from the injection molding of 0 to the stretch blow molding and removal of the bottle-shaped molded product 41 is carried out by the lifting plate 5 and the transfer plate 8.
This is carried out continuously by the lifting and lowering operations of , and the intermittent rotation of the transfer plate 5 every 120 degrees.

【0039】

Effects of the Invention As described above, the present invention includes a lifting plate and a mold clamping plate that are vertically movably inserted into the tie rod between the base and the support plate above the base. A circular transfer plate is provided, which rotates intermittently at intervals of 300 degrees, and has holding molds on three sides of the lower surface.
The stopping position of the holding mold is used as an injection operation part, a stretching blowing operation part, and an ejection operation part, and the holding mold, an injection cavity mold for closing the mold, and a blowing cavity mold are installed on the base, and the injection cavity mold is A mold clamping device is provided on the upper support plate by connecting a mold clamping ram to the mold clamping plate, and the injection cavity mold and the mold are passed through the holding mold through openings formed in the lifting plate and the transfer plate. The closing injection core is attached to the lower side of the mold clamping plate, and an elevating device using a cylinder and piston rod that moves the elevating plate up and down together with the transfer plate is provided between the base and the elevating plate, resulting in the following effects. play.

[0040] Since the transfer plate provided on the lifting plate is free in the vertical direction, its height position can be changed together with the lifting plate within the extension range of the piston rod of the lifting device, and the height of the molded product can be changed. Since it is possible to adjust the height of the molded product, there is no restriction on the height of the molded product, and there is no need to raise the height of the injection and blow cavity molds even when molding small bottles.

[0041] The injection cavity mold is installed on the top surface of the base, and the mold is opened and closed by moving the transfer board up and down, so the injection device can be placed with the nozzle touching the injection cavity mold or hot runner block at all times.
There is no longer a need to touch the nozzle each time the mold is opened or closed, which was previously required, and resin leakage from the injection device is also eliminated.

[0042] Since mold clamping is performed on the injection cavity mold installed on the top surface of the base, there is no need to provide mold clamping devices at two locations, upper and lower. In addition, even if the transfer plate is sandwiched between the injection cavity mold and the mold clamping plate together with the lifting plate, it is not restrained in the vertical direction, so it will not bend due to the mold clamping force. There is no uneven thickness of the preform caused by warping and bending.

[0043] The elevating device raises and returns the elevating plate, and the preform and molded product extracted from the injection and cavity molds are rotated and transferred to the next operating section at the top of the mold, so even if there is a mold on the top surface of the base, the transfer is easy. In addition, there is no need for the opening dimension of the blow cavity mold to be significantly larger than the diameter of the molded product, as in the past.

[0044] Since the holding molds are arranged on three sides of the lower surface of the transfer plate, the installation area of the holding molds is wider than when holding molds are arranged on all four sides, and the holding molds are configured to be horizontally long. Since it is possible to increase the number of molded products, it has better mass productivity than conventional molding machines.

[0045] Since the number of holding molds and the number of mold clamping devices are reduced, various related devices are also unnecessary, and the entire molding machine is simplified, so maintenance management is easier than with conventional molding machines. It has the advantage of being easy to use and reducing costs.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional side view extending from the injection operation section to the stretch blow operation section when the mold is closed in the injection stretch blow molding machine according to the present invention.

FIG. 2 is a longitudinal side view extending from the injection operation section to the stretch blow operation section when the mold is opened.

FIG. 3 is a longitudinal sectional front view of the injection operation section during mold opening.

FIG. 4 is a plan view with the upper part cut away from the mold clamping plate.

FIG. 5 is a longitudinal sectional side view of the mold release operation section.

[Explanation of symbols]

1... Machine base 2... Base 3... Support plate 4... Tie rod 5... Elevating plate 6... Mold clamping plate 7... Drive device 8... Transfer plate 12... Holding mold 13... Injection cavity Mold 17...Injection core 18...Mold clamping device 19...Mold clamping rod 20...Blowing cavity mold 23...Blowing core 24...Extension rod 25...Extending device 28...Ejecting device 30...Mold opening plate 31 ...Elevating device 31a...Cylinder 31b...Piston rod.

Claims (1)

[Claims] A support plate is connected with a plurality of tie rods above a base fixed on the machine base, and a lift plate and a mold clamping plate on the top of the lift plate are movable up and down on the tie rods between the support plate and the base. A circular transfer plate is installed below the elevator plate and rotates intermittently at 120 degree intervals by a drive device installed at the center of the upper side of the elevator plate, and the transfer plate opens and closes in the radial direction on three sides of the lower surface of the transfer plate. A flexible holding mold is attached, and the stopping positions of the holding mold are used as an injection operation part, a stretch blowing operation part, and an ejection operation part, and the holding mold and an injection cavity mold and a blowing cavity mold that close the mold are placed on the base. A mold clamping device is installed on the support plate above the injection cavity mold by connecting a mold clamping ram to the mold clamping plate, and the holding mold is penetrated through the openings made in the lifting plate and the transfer plate. Then, an injection core that closes the injection cavity mold is attached to the lower side of the mold clamping plate, and an elevating device using a cylinder and a piston rod that moves the elevating plate up and down together with the transfer plate is provided between the base and the elevating plate. An injection stretch blow molding machine comprising: