JP2003155020A - Injection molded synthetic resin container and production equipment for its mold structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection molded container with a uniform thickness having a threaded mouth part and a body part having a diameter larger than that of a mouth part, and provide a mold structure capable of economically producing the same. SOLUTION: This molded container can be released from a mold even if the container is injection-molded. This container is made of an elastic synthetic resin, has the body part 2 having an inner diameter larger than that of the mouth part 1 with its stepped part connected with R-curved lines 7, 8 in a smooth undercut shape and has a uniform thickness. A multi-staged loose piece structure and function are employed in a mold core for molding the container and for releasing the threaded part 4 and the body part 2. On the first stage, in order to easily release the mold of the threaded part undercut, the cavity plate for the threaded part is moved forward for releasing the same from a mouth inner diameter core, on the second stage, a body inner diameter core is moved forward for releasing the threaded part 4 of the molded container, and on the third stage an ejecting core is moved forward from the bottom 9 of the container for releasing the container (A) from the body inner diameter core.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection-molded container and a mold structure manufacturing apparatus.

[0002]

2. Description of the Related Art Conventional injection-molded containers generally have a straight inside shape in which the inner part of the mouth and the inner part of the body have no undercut from the mouth to the body. Further, there are many cases in which the screw portion has a split-type structure in which the screw portion operates left and right. In the case where the shape of the body and mouth of the container is smaller than that of the body of the container as in the case of the BLOW molding method, the injection-molded container cannot be demolded.

In the conventional method for producing a synthetic resin container, many blow molding containers are commercially available. However, there is a limit to the number of blow molds. In particular, in the case of a wide-mouthed container, the mouth is secondarily processed. It had the above drawbacks. Also, injection and blow containers have become commercially available, and PE
It seems that it has become possible to produce T bottles and wide-mouthed containers, but since these manufacturing devices are mass-produced, they are commercially available containers such as PET bottles and are related to pharmaceuticals and cosmetics. In the wide-mouthed container, universality is economically problematic because the cost of the mold and the equipment of the manufacturing machine is high.

[0004]

The conventional injection-molded container is a container having a shape without undercut in the inner diameter of the mouth and the inner diameter of the body, and has a complicated split-type structure in which the screw portion operates left and right. In a container formed by a mold, the side wall dimension of the body portion becomes thicker, and sink marks due to the contraction of the surface are apt to occur, resulting in a defect in appearance quality. In addition, the method of forming the screw part is low in productivity because the mold structure is a split mold to separate the undercut of the screw, and the number of molds formed from the mold is limited in one row direction, so productivity is low. There was a problem.

According to the present invention, the container inner diameter portion 2 of the container (A) is larger than the inner diameter portion 1 of the container (A) by connecting an undercut portion having a step of the body portion with an R-shaped curved portion. An injection molding die having a function and structure that can be released from the inner diameter portion 1 and can be released from the molded screw portion 4 by applying the elasticity of synthetic resin, and is an economical container with high productivity. Is intended to provide.

[0006]

In order to achieve the above object, the present invention provides a container inner diameter portion larger than the inner diameter portion (1) in a container of an injection molding method using a synthetic resin material having appropriate elasticity. A container formed of (2) and a bottom part (9), and in the outer shape of the container, a screw part (4) is provided on the outer peripheral part of the neck-long part (3), and a step (5) is provided below it.
The outer peripheral portion (2b) of the body portion (2a) has a rounded shape (6) and a bottom seat portion (10) at the upper portion, and the step portion between the inner diameter portion (1) and the inner diameter portion (2) is The structure of the container was formed in a shape connected by the R curve portions (7) and (8).

In order to manufacture the above-mentioned container, the mold structure of the present invention is constructed in the form of a pinpoint gate system, and has a fixed side mounting plate (20) and a runner stripper plate (2).
1) and the fixed side mold plate (22) to the cavity bush (2
8), the runner groove (43) and the pinpoint gate (44) are provided, and the runner lock pin (29) is inserted into the fixed side mold and the movable side mold plate (23). ) Is inserted and the core holder plate (2
4) is a mold structure in which a core (36) for the inner diameter of the mouth is inserted and formed by a receiving plate (25), a spacer block (26) and a movable side mounting plate (27).

Particularly, in the form of the container (A), the structure of the multi-step core for removing the screw portion (4) and the inner diameter portion (2) from the inner diameter portion (1) is provided, and the inner diameter core (37) The core hollow shaft (37b) that slides to the inner diameter of the mouth inner diameter core (36) and the lower surface portion (37a) have the mouth inner diameter core (3).
It is formed in an integral shape for setting on the upper surface portion of 6), and the upper surface portion (38a) of the projecting core pin (38) is provided near the circumference of the upper surface portion of the body inner diameter core (37) and has an umbrella-shaped taper. The portion (38b) is in sliding contact with the tapered portion of the body inner diameter core (37), and the projecting core bottom surface portion (38c) is in sliding contact with the bottom surface portion of the body inner diameter core (37) and is integral with the core shaft (38d). It is a structure of a split core that is formed as a whole.

The ejector plates (33a) (33b) for operating the body inner diameter core (37) are provided with a key holder (40) and a half-moon shaped key (41) provided near the lower surface of the core hollow shaft (37b). Has been installed. The core shaft (38d) is attached to the ejector plates (34a) (34b) for actuating the projecting core pin (38).
It is fitted by a key ring (40a) and a half-moon shaped key (41a) provided near the lower surface of the.

In addition, a spring (42) is inserted into the core holder plate (24) to operate the movable side mold plate, and the stop bolt (32) is screwed into the receiving plate (25). -To fit the ejector-guide pin (31) in order to stabilize the sliding movement of the plates (33a) (33b) and the ejector plates (34a) (34b), and to retract the projecting core pin (38) to the normal position. The return pin (30) was fitted into the mold structure of the injection-molded container.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described based on examples with reference to the drawings. In FIG. 1, reference numeral A
Shows the shape of the container molded by injection molding.
It is integrally molded with a synthetic resin material having appropriate elasticity.

The container A of the present invention is a container having a bottom portion 9 having a diameter of the trunk inner diameter portion 2 larger than that of the mouth inner diameter portion 1 and having a bottom portion 9 with a screw portion 4 formed on the outer peripheral portion of the neck length 3. 5 is provided on the upper portion of the body outer peripheral portion 2b of the body portion 2a, the R shape 6 and the bottom seat portion 1
In the step portion between the inner diameter 1 of the mouth and the inner diameter 2 of the body, an R curve portion 7 and an R curve portion 8 are formed in a smooth undercut shape of a connecting curve shape. The inner diameter portion 2 is a container manufactured by easily separating from the inner diameter portion 1 of the mouth.

In order to manufacture the above container, FIGS.
It is an embodiment which sequentially shows an injection molding die structure and an operating structure for separating and taking out a molded container.

Regarding the mold structure of the present invention, the names, shapes, functions, etc. of parts for general mold structures, such as guide pins for operating each plate, bushes, sprue bushes, mold cooling, etc. The description of the hole portion and the cap bolt for mounting each portion is omitted, and the pin point gate and the runner type mold structure relating to the present invention are required, and are required for the molding process of the injection molding container of the present invention and the mold releasing process. It is an Example which shows the structure of a fixed side metallic mold and a movable side metallic mold.

FIG. 3 shows a pin-point gate type mold structure for molding a container, in which the gate is a shape injected from the bottom rear surface of the container. The fixed side mold includes a fixed side mounting plate 20, a runner plate 21, a cavity bush 28 inserted in the fixed side mold plate 22, and a runner lock pin 29.
And the runner groove 43 and the pinpoint gate portion 44.

In the movable side mold structure, the screw side cavity bush (35) is inserted in the movable side mold plate (23), and the inner diameter core (36) is inserted in the core holder plate (24). 25), a spacer block (26) and a movable side mounting plate (27).

Particularly, the shape of the movable core is the function and structure of the multi-step core which separates the screw portion 4 and the inner diameter portion 2 from the inner diameter portion 1 from the shape of the container A. 37) is a core hollow shaft (37b) that slides to the inner diameter of the mouth inner diameter core (36), and a lower surface portion (37a) is integrally formed with the upper surface portion of the mouth inner diameter core (36) to form a protruding core pin. Upper surface of (38) (38
a) is provided near the circumference of the upper surface of the body inner diameter core (37), and the umbrella-shaped tapered portion (38b) is provided on the body inner diameter core (3).
The core bottom surface (38c) for sliding contact with and protruding from the tapered portion (7) has a sliding contact surface on the bottom surface of the body inner diameter core (37) and is formed integrally with the core shaft (38d). It is a split core structure.

The ejector plates (33a) (33b) for operating the body inner diameter core (37) are provided with a key holder (40) and a half-moon shaped key (41) provided near the lower surface of the hollow core shaft (37b). Has been installed. The core shaft (38d) is attached to the ejector plates (34a) (34b) for actuating the projecting core pin (38).
It is fitted by a key ring (40a) and a half-moon shaped key (41a) provided near the lower surface of the.

Further, a spring (42) is inserted into the core holder plate (24) to operate the movable side mold plate, and the stop bolt (32) is screwed into the receiving plate (25). -To fit the ejector-guide pin (31) in order to stabilize the sliding movement of the plates (33a) (33b) and the ejector plates (34a) (34b), and to retract the projecting core pin (38) to the normal position. 2 is a mold structure of an injection molding container configured by fitting a return pin (30).

The embodiment shown in FIG. 4 shows a working state of the mold when the injection molding machine starts to open the mold. When the fixed-side mold is opened, the mold plate 23 of the movable-side mold in which the screw portion cavity bush 35 is inserted is opened by the spring 42, and the container formed by being fixedly placed by the stop bolt 32 has a screw portion. When the body inner diameter core and the projecting core 4 are interlocked and actuated forward with 4 in the screw cavity, a gap is formed in the outer peripheral portion of the mouth inner diameter core and the inner wall portion of the neck portion 3 of the container. It is a figure which shows the state which the screw part 4 formed in the outer peripheral part of the neck long part 3 elastically easily mold-releases.

The embodiment shown in FIG. 5 shows the state of operation of the mold when the injection molding machine has completed the mold opening. The ejector plate 33a is slidably connected to the ejector plates 33a and 33b fitted with the pulling shaft fittings 45 attached to the fixed-side mold plate 22 and the body inner-diameter core 37 of the movable-side mold. Three
The body inner diameter core 37 fitted in 3b moves forward, and the outer peripheral screw portion 4 of the neck portion 3 of the molded container (A)
Shows a state where they are elastically separated. At this time, a particularly important element is that the inner diameter portion 1 of the container has a screw portion 4 due to the gap.
FIG. 7 is a diagram showing that the undercut portion of FIG.

The embodiment shown in FIG. 6 shows a working state of a mold when the ejector shaft of the molding machine advances after the completion of mold opening of the injection molding machine. As the ejector shaft of the molding machine moves forward, the ejecting cores 38 fitted to the ejector plates 34a and 34b are protruded.
The container A is pushed forward from the inner surface of the bottom 9 of the container by the core top surface portion 38a. In this case, a particularly important factor is that in the body inner diameter portion 37, the step portion between the mouth inner diameter portion 1 and the body inner diameter portion 2 is formed into a smooth undercut shape by the R-shaped curved portions 7 and 8. Due to the elasticity of the resin, the body inner diameter core 37 is easily separated from the inner peripheral portion of the formed inner diameter portion 1.

At this time, a state in which the inner peripheral surface of the body inner diameter portion 2 of the molded container and the outer peripheral surface of the body inner diameter core are in close contact with each other in a vacuum state is provided in the body inner diameter core 37 with an air passage hole portion. Three
It is a figure which shows the function and structure which relieve | moderate operation | movement of the protrusion core and mold release of a container by 9 substantially.

[0024]

The container (A) of the present invention according to claim 1 is embodied in the form described above, and has the following effects. Conventional injection-molded containers are limited to a single-row or two-row array structure of cavities and cores because the shape of the body and the mold release structure of the screw part are complicated split mold structures. However, there was a problem that productivity was low. The form of the container of the present invention has a form in which it can be released from the mold with an injection molding die and has a structure in which a plurality of pieces can be arranged in a plurality, so that it has high productivity and an economical effect. Also in terms of the appearance quality of the container, since the thickness of the body is uniform, sink marks in the body appearance due to shrinkage after molding are eliminated, and the printing accuracy is improved even in the secondary process of printing on the body, There is an effect that the appearance quality is guaranteed.

[Brief description of drawings]

FIG. 1 shows an embodiment of an injection container according to the present invention,
FIG. 3 is a cross-sectional view taken along the E-line of FIG. 2.

FIG. 2 is a plan view of the container A.

FIG. 3 is a cross-sectional view showing a mold structure for manufacturing the container.

FIG. 4 is a cross-sectional view showing a first stage operation state of the mold when the mold opening is started.

FIG. 5 is a cross-sectional view showing a second stage operation state of the mold when the mold opening is completed.

FIG. 6 is a cross-sectional view showing a state in which a container molded by a projecting core that is interlocked with the advancement of an ejector shaft of an injection molding machine is released from a mold.

[Explanation of symbols]

A injection molding container 1 mouth inner diameter 2 inner diameter 3 neck length 4 screw part 5 steps 6 R section 7 R curve section 8 R curve section 9 bottom 10 Bottom seat 20 Fixed side mounting plate 21 runner stripper plate 22 Fixed side template 23 movable side template 24 core holder plate 25 support plate 26 Spacer block 27 Movable side mounting plate 28 cavity bush 29 runner lock pin 30 Return pin 31 ejector guide pin 32 stop bolts 33a Ejector on plate 33b Ejector plate bottom 34a ejector on plate 34b Ejector plate bottom 35 Screw Cavity Bush Core for 36 ports 37 Core for Inner Diameter 37a Body inner diameter core bottom part 37b Body inner diameter core Hollow shaft 38 Core for protrusion 38a Core top surface part 38b core taper part 38c Core bottom part 38d core shaft 39 air holes 40 keychain 41 Half Moon Key 40a key holder 41b Half moon key 42 spring 43 runner 44 pinpoint gate 45 Tension shaft fittings 46 Tension shaft Ejector shaft for N molding machine

Continued front page    F-term (reference) 3E033 AA04 BA13 CA06 DA03 DB02                       DD01 FA02                 4F202 AG07 AG23 AH55 CA11 CB01                       CK02 CK06 CK32 CK42 CK53                       CM02 CM07 CM31

Claims (2)

[Claims] 1. A container according to an injection molding method using a synthetic resin material having an appropriate elasticity, the container having an inner diameter portion (2) larger than an inner diameter portion (1) and a bottom portion (9), Regarding the outer shape of the container, a screw portion (4) is provided on the outer peripheral portion of the neck portion (3) and a step (5) is provided on the lower portion thereof, and an R shape (on the upper portion of the outer peripheral portion (2b) of the body portion (2a) ( 6) and the bottom seat (10) at the bottom, and the step portion between the inner diameter portion (1) and the inner diameter portion (2) of the mouth is connected by the R curve portions (7) and (8). Injection molded container formed by. 2. A mold structure for manufacturing an injection-molded container is constructed in the form of a pinpoint gate system and has a fixed side mounting plate (2).
0), runner stripper plate (21), fixed side mold plate (22), cavity bush (28) is inserted, runner groove (43) and pinpoint gate (44) are provided, and runner lock pin (29) is inserted. The fixed side mold and the movable side mold plate (23) are provided with a screw portion cavity bush (35).
And a movable side mold formed by a receiving plate (25), a spacer block (26) and a movable side mounting plate (27) by inserting a core inner diameter core (36) into the core holder plate (24). In the multi-stage core removal structure in which the screw portion (4) and the inner diameter portion (2) of the container (A) are separated from the inner diameter portion (1), the inner diameter core (37) is the inner diameter core (37). 36) The hollow core shaft (37)
b) and the lower surface (37a) are integrally formed with the upper surface of the mouth inner diameter core (36), and the upper surface (38a) of the projecting core pin (38) is the upper surface of the body inner diameter core (37). An umbrella-shaped tapered portion (38b), which is provided near the circumferential portion of the portion, is in sliding contact with the tapered portion of the body inner diameter core (37), and the protruding core bottom portion (38c) is the body inner diameter core (37). ) Is in sliding contact with the bottom of the core shaft (38d) and is integrally formed with the core shaft (38d). A key holder (4) provided near the lower surface of the core hollow shaft (37b) on the ejector plates (33a) (33b) for operating the body inner diameter core (37).
0) and half-moon shaped key (41). A key holder (40a) provided near the lower surface of the core shaft (38d) and a half-moon shaped key (4) on the ejector plates (34a) (34b) for operating the projecting core pin (38).
1a). In addition, a spring (42) is inserted into the core holder plate (24) to operate the movable side mold plate 23, and the stop bolt (32) is screwed into the receiving plate (25). 33a) (33b) and ejector plate (34
a) An injection formed by fitting an ejector guide pin (31) for stabilizing the sliding movement of (34b) and a return pin (30) for retracting the projecting core pin (38) to the normal position. Manufacturing equipment for mold structure of molding container.