JP3337756B2 - Blow molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow molding machine,
In particular, the present invention relates to a blow molding machine provided with a means for cutting gate marks on a preform.

[0002]

2. Description of the Related Art Conventionally, a so-called four-station molding machine called a hot parison system or a one-stage system is known as a blow molding machine for performing stretch blow molding while retaining the amount of heat during injection molding of a preform. I have.

A four-station molding machine injects a molten resin into an injection cavity, cools it to form a preform, adjusts the temperature of the preform, and then performs blow molding in a blow cavity mold. Then, the final container is taken out by an ejector.

When a bottomed preform is molded by this blow molding machine, a gate mark protrudes from the bottom of the injection-molded bottomed preform. If the gate mark is untreated, the appearance of the bottom of the final container may be impaired, and the following means are known as means for eliminating this.

As a first conventional example, Japanese Patent Publication No. 58-3789 is disclosed.
Japanese Patent Application Laid-Open No. 5 (1999) -175566 discloses that a through hole is provided in a bottom portion of a blow cavity mold, a bottomed preform is inserted into a blow cavity so that the gate mark protrudes into the through hole, and the gate mark is formed by a pressing member and an extension rod. A means for crushing and flattening is disclosed.

As a second conventional example, Japanese Patent Publication No. Sho 58-5
Japanese Patent No. 4978 discloses means for cutting the gate mark with one cutter while the preform having a bottom is being conveyed from the injection molding station to the temperature control station.

Further, as a third conventional example, Japanese Patent Publication No.
Japanese Patent No. 40366 discloses that a through hole is provided at the bottom of a temperature control pot, a bottomed preform is inserted into a temperature control cavity, the gate mark protrudes into the through hole, and the gate mark is sandwiched between two cutters. Means for cutting are disclosed.

[0008]

However, in each of the above conventional examples, there are the following problems.

First, in the first conventional example, since the gate marks are hard, the gate marks are not completely eliminated only by crushing, and are blow-molded with the convex portions remaining at the bottom of the bottomed preform. As a result, the commercial value of the final container was reduced. In addition, there is a problem in that if a misalignment occurs in the bottomed preform, a gate mark cannot be inserted into the through hole.

[0010] Next, in the second conventional example, it is necessary to reduce the speed of the rotary conveyance in order to reliably cut the gate mark during the rotation and conveyance of the bottomed preform. There is a problem that the cycle time for molding the final container increases and the throughput decreases. In addition, since the gate mark is cut by the force of the preform moving with respect to the cutter, the bottomed preform may be bent. Further, the probability of reliably cutting the gate mark was lower than when using a nipper-shaped cutting member.

Next, in the third conventional example, the temperature control pot may drop without completely cutting the gate mark, and then the gate mark falls from above into the temperature control pot, and Traces sometimes adhered to the temperature control cavity surface. Further, even though the gate mark could be cut, threading of the resin occurred, and this thread sometimes adhered to the surface of the temperature control cavity. In any of these cases, the temperature could not be sufficiently controlled where the gate mark or the resin thread adhered. Furthermore, gate marks or stringing adhered to the temperature-regulating pot may adhere to the preform and impair the appearance of the final container.

SUMMARY OF THE INVENTION The present invention has been made to eliminate the drawbacks of the prior art, and has as its object to completely cut a gate mark of a bottomed preform and to form a cut piece of the gate mark on the surface of a temperature control cavity. It is an object of the present invention to provide a blow molding machine capable of performing sufficient temperature control without adhering resin or resin threads.

[0013]

To achieve the above object, according to an aspect of blow molding machine according to claim 1 is morphism denars form, a bottomed preform which is conveyed in a state in which retain heat during the molding In a molding machine having a temperature control station arranged in a temperature control means and performing temperature control before blow molding, the temperature control station includes a gate cutting device at a position avoiding a conveying path of the bottomed preform to be conveyed. The gate cutting device includes a cut section for cutting a gate mark of the bottomed preform located outside the temperature control means, and a collecting section for collecting a gate piece cut by the cut section. , The cutting portion has a cutting portion that cuts across the gate mark, and a cutting portion moving unit that moves the cutting portion to a position where the gate mark can be cut, and cuts the gate mark, The collection unit is A receiving unit that receives the gate piece cut by the cutting unit, and a receiving unit moving unit that moves the receiving unit to a position where the gate piece can be received, and collects the gate piece, I do.

According to a second aspect of the present invention, in the blow molding machine according to the first aspect, the cutting portion moving means moves the closed cutting portion downward in a closed state.

[0015]

In the blow molding machine according to the first aspect, after the preform is carried into the temperature control station,
After or before the temperature control operation using the temperature control device, the cutting portion is moved to a position where the gate mark of the preform existing outside the temperature control device can be cut, and the gate mark is cut, and the cut gate piece is cut. Collect.

At this time, the cut gate piece is received and collected by the receiving section, so that the gate piece does not fall into the temperature control means. Similarly, the stringed resin thread is also collected by the receiving section, so that it does not enter the temperature control means and does not adhere to the temperature control cavity. Therefore, the trace of the gate or the resin thread does not adhere to the preform and does not impair the appearance of the final container.

Since the temperature control operation is performed in a shorter time than the preform molding operation, the cycle time does not increase even if the gate mark cutting operation is sufficiently secured.

Further, in the blow molding machine according to the second aspect, since the cutting portion moves downward while sandwiching the gate mark, it can be cut while pulling the gate mark, and the gate mark can be completely and reliably removed. Can be cut.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a blow molding machine 200 according to an embodiment.
FIG. In FIG.
The rotating disk 220 is provided on the machine 210 of the No. 0, and the rotating disk 220 can rotate intermittently with respect to the machine 210 in the direction of the arrow shown in the figure. The preform injection-molded at the injection molding station 202 is held by the lip mold 10 and rotated by the rotating plate 220 to perform a temperature control step of the preform. Each of the stations passes through a stretching blow station 206 that executes a stretching blow step and an eject station 208 that executes a step of taking out a molded product.

Here, a side view of the temperature control station 204 is shown in FIG. The temperature control station 204 is a lip type 1
0, a temperature control pot 20, and a gate cutting device 30.

The lip mold 10 has a pair of split dies 10a and 10a which can be opened in the left-right direction in the figure, and
The preform 300 has a lip cavity surface (not shown) that defines an outer wall of a lip portion (not shown) of the preform 300, and holds the preform 300.
A gate mark 300a is formed at the bottom of 0.

The temperature control pot 20 has a temperature control cavity (not shown) formed therein so that the preform 300 can be accommodated in the temperature control cavity. The temperature control pot 20 is configured by stacking ring-shaped temperature control blocks 24 divided into three stages in the vertical axis direction, and each temperature control block 24 is provided with hot water or the like controlled at a predetermined temperature. A water passage for circulating the temperature control medium and a heater (not shown) of an electric resistance heating type are provided so that the temperature can be controlled.

The gate cutting device 30 includes a cutter 40, a collecting tray 50, and a driving unit 60, and is provided outside the conveying path of the preform 300, and is used for conveying the preform 300 and controlling the temperature of the preform 300. It does not hinder the insertion operation.

The cutter 40 cuts the gate mark 300a, and in this embodiment, for example, an air-driven nipper is used. Since the cutter 40 cuts with the gate mark 300a interposed therebetween, the preform 300 is not bent at the time of cutting.

A collecting plate 50 is provided so as to cover the lower portion of the cutter 40, and the cut gate mark 3 is cut.
00a can be received. A collecting hole 52 is formed in the collecting plate 50, and the collecting plate 50 is inclined from the tip end toward the collecting hole 52, and a collecting pipe 54 is provided in the collecting hole 52 in communication therewith. The collection pipe 54 is connected to a suction pump (not shown). Therefore, the gate mark 300a received by the collection plate 50 is sucked from the collection pipe 54 so as not to enter the temperature control pot 20.

The cutter 40 and the collecting plate 50 are integrated via the apparatus main body 30a, and a driving section 60 is provided as a means for moving the position of the apparatus main body 30a. The drive section 60 includes a horizontal drive section 62 for moving the apparatus main body 30a in the horizontal direction, and a vertical drive section 64 for moving the apparatus main body 30a in the vertical direction. Each of the horizontal drive unit 62 and the vertical drive unit 64 drives the piston inserted into the cylinder by hydraulic pressure, but is not limited thereto, and may be driven by another reciprocating method. .

The driving section 60 is provided with a gate mark 300
Vertical and horizontal movement strokes are set in advance so that the cutter 40 can move to a position where the cutter a can be completely cut from the root. Further, it is preferable that a sensor such as a known optical sensor is provided so that it can be confirmed that the cutter 40 is arranged at a position corresponding to the gate mark 300a.

This embodiment is configured as described above.
Hereinafter, the operation will be described.

FIG. 2 shows a state where the preform 300 is held by the lip mold 10 and conveyed to the temperature control station 204.

Then, first, the temperature control pot 20 is raised, the preform 300 is stored in the temperature control pot 20, a temperature control step is performed, and after this temperature control step is completed, the temperature control pot 20 Descends and returns to the state before the temperature control step. This temperature control step may use a temperature control core or preliminary blow air.

Next, the position of the gate mark 300a of the preform 300 is detected by a sensor (not shown). As shown in FIG. 3, the horizontal drive unit 62 moves the cutter 40 horizontally to a position immediately below the gate mark 300a. To move the apparatus body 30a. Then, as shown in FIG. 4, the apparatus main body 30a is raised in the vertical direction by the vertical drive unit 64, and the cutter 40 is arranged at a position corresponding to the base of the gate mark 300a.

Thus, the cutter 40 has the gate mark 300a.
Can be sandwiched at the base, and the gate mark 300a can be cut. However, the gate mark 300a is softened by the retained heat and may not be easily cut. Therefore, the gate mark 300a is reliably cut by lowering the apparatus main body 30a with the cutter 40 sandwiching the gate mark 300a and cutting the gate mark 300a while pulling the gate mark 300a. As shown in FIG. 5, the cut gate mark 300 a is received by the collection dish 50, rolls in the direction of the collection hole 52, and is sucked and collected from the collection pipe 54.

When the apparatus body 30a descends with the cutter 40 sandwiching the gate mark 300a, stringing of the resin may occur. However, this resin thread is collected similarly to the cut gate mark 300a. It is received by the plate 50 and is sucked and collected from the collection pipe 54 through the collection hole 52.

Then, the drive unit 60 causes the apparatus body 30a
Is moved outward of the rotating plate 220 to return to the original state shown in FIG. Thus, the gate cutting device 30 is arranged at a position that does not hinder the conveyance of the preform 300,
By rotating the rotating plate 220, the preform 300 can be transported to the next stretch blow station 206 (see FIG. 1). In this stretching blow step, the preform 300
Is a preform having no gate mark 300a, so that a final container having good appearance after stretch blow molding can be obtained.

Generally, in a blow molding machine,
Since the temperature adjustment step is completed in a shorter time than the injection molding step of the preform, in the blow molding machine 200 of the present embodiment, the gate mark 300a is cut using the idle time after the temperature adjustment step. Things. Therefore, there is no need to extend the total process time until the final container is formed, and it is not necessary to perform difficult control for performing the gate mark cutting step simultaneously with other steps.

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

For example, in the embodiment, the cutting operation of the gate mark is performed after the temperature control step. However, the present invention is not limited to this, and the cutting operation of the gate mark can be performed before the temperature control step. . Gate marks are hardened in the cooled state and are easier to cut.In particular, if the temperature control step is a temperature control step of cooling the preform, the gate marks may be removed after the temperature control step. Preferably, a cutting operation is performed.

Further, for the same reason, the gate mark is separated from the state where the cutter 40 sandwiches the gate mark 300a in FIG. 4 until the cutter 40 is lowered as shown in FIG. Can be cooled to facilitate cutting.

[0040]

As described above, in the blow molding machine according to the first aspect, the cut gate pieces and the threaded resin thread are collected by the receiving section, and these are collected in the temperature control pot. Prevents the temperature control pot from continuously penetrating into the temperature control cavity and maintaining the proper temperature control effect of the temperature control pot. In addition, the gate piece or thread string adheres to the preform and impairs the appearance of the final container. There is an effect that can be prevented.

Further, since the gate trace is cut after or before the temperature control step which is completed in a relatively short time, an increase in cycle time can be prevented.

In the blow molding machine according to claim 2,
The cut portion has an effect that the gate mark can be completely and reliably cut while pulling the gate mark.

[Brief description of the drawings]

FIG. 1 is a plan view showing a blow molding machine according to an embodiment.

FIG. 2 is a side view showing a mold structure of a temperature control station in the blow molding machine according to the embodiment.

FIG. 3 is a side view showing a state in which the cutter has moved to a position immediately below a gate mark in the mold structure of FIG. 2;

FIG. 4 is a side view showing a state where a cutter is raised and a gate mark is sandwiched in the mold structure of FIG. 2;

FIG. 5 is a side view showing a state in which the cutter descends and a gate mark is cut in the mold structure of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lip type 20 Temperature control pot 30 Gate cutting device 40 Cutter 50 Collection dish 60 Drive part 300 Preform 300a Gate mark

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 49/00-49/80 B29B 11/06

Claims (2)

(57) [Claims] 1. A is morphism denars form, a bottomed preform which is conveyed in a state in which retain heat during the molding, it has a temperature regulating station for temperature control before the blow molding was placed in the temperature control unit In the molding machine, the temperature control station includes a gate cut device at a position avoiding a conveyance path of the bottomed preform to be conveyed, and the gate cut device includes the bottomed preform located outside the temperature control unit. A cut section for cutting the gate mark, and a collecting section for collecting a gate piece cut by the cut section, wherein the cut section cuts across the gate mark, and the gate mark Cutting section moving means for moving the cutting section to a position at which the cutting section can be cut, and cutting the gate mark, the collecting section receiving a gate piece cut by the cutting section, Get The door member and a receiving portion moving means for moving the receiving unit to receive a position capable recovering the gate pieces, blow molding machine, characterized in that. 2. The blow molding machine according to claim 1, wherein the cutting section moving means moves the cutting section in a closed state downward.