JP2010013114A - Synthetic rein-made pull-open middle plug, and mold for molding the plug - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pull ring integrated with a horizontal rib exhibiting a large anti-skid effect by molding the horizontal rib in a "force-out" molding manner without considerably reducing the projecting height of the horizontal rib, in a pull-open middle plug. <P>SOLUTION: In the pull-open middle plug 1, the anti-skid horizontal rib 3 is erected in an inclined posture on the pull-out direction side of a mold for molding on an inner peripheral surface of the pull-ring 2 with a fill-up finger tip hooked thereto. Since the horizontal rib 3 is inclined, the substantial projecting height of the horizontal rib 3 is increased to improve the hooking of the finger tip. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pull-open inner stopper that pulls a pull ring to form an opening by fracture, and a molding die for the same.

As a conventional example showing a technique for forming a rib-shaped lateral rib extending in the circumferential direction in order to improve the catch of the fingertip that applies a pulling force to the pull ring on the inner peripheral surface of the pull ring of the pull-open plug, There is one disclosed in Japanese Unexamined Patent Publication No. 2003-221054.
JP 2003-221054 A

  The technique disclosed in this conventional example shows means for forming a pull ring with an outer core mold and an inner core mold. When releasing a molded product, the inner core mold is first extracted to expose the inside of the pull ring. After that, by pulling out the outer core mold, an attempt is made to satisfactorily achieve “reasonable removal” of the main body portion of the pull ring.

  Although the above-described conventional technology can satisfactorily achieve “forced removal” of the main body portion of the pull ring, including the conventional technology, the inner circumference of the pull ring has been conventionally improved by the inner core mold that has been extracted first. There has been a problem that “unreasonable” cannot be satisfactorily achieved by the protruding rib-shaped anti-slip lateral ribs protruding along the circumferential direction on the surface.

  That is, the lateral rib protruding from the inner peripheral surface of the pull ring is a portion that is “forcedly removed” from the inner core mold that is first extracted, so there is no room to escape from the contact with the mold. The degree of protrusion is greatly limited, and a sufficient anti-slip effect cannot be exhibited.

  Specifically, as shown in FIG. 7A, the protrusion height is allowed according to the elasticity exerted by the pull ring 2, and there is little catching with the inner core mold to be extracted. The cross-sectional shape along is designed to be an arc shape, and is formed as the in-mold lateral rib 3a.

  In this way, since the in-mold lateral rib 3a is greatly limited in consideration of “unreasonable removal”, as shown in FIG. Although it is “forcedly pulled out” with little collapse and is formed into the horizontal rib 3, the projecting height is small, so that the required anti-slip action cannot be exhibited.

  For this reason, in order to improve the catch of the fingertip, as shown in FIG. 8 (a), a "step part" for bathing the catch is formed on the top of the in-mold lateral rib 3a to form the in-mold lateral rib. When 3a is formed, the inner core mold is caught by this "step" when the inner core mold is extracted, and the lateral rib 3 that has been "unreasonably removed" is shown in FIG. 8 (b). The top portion provided with the “step portion” was scraped off almost half and formed into a state extending thinly in the die-cutting direction, and did not exhibit a high anti-slip action.

  In addition, in the general prior art shown in FIG. 7, for the purpose of forming the horizontal rib 3 having a large protruding height, as shown in FIG. 9 is increased, as shown in FIG. 9 (b), the obtained lateral rib 3 is formed in a state where the substantially increased height is cut off and thinly extended in the die-cutting direction, as shown in FIG. In the same manner as above, the anti-slip action was not achieved.

  Therefore, the present invention was devised to solve the above-described problems in the prior art, and it is technically possible to form the lateral ribs without excessive reduction in the protruding height. It is an object to obtain a pull ring integrally formed with a lateral rib that exhibits a large anti-slip action.

  The first main structure of the present invention is a synthetic resin pull-open in which an opening is formed by removing a portion surrounded by a fracture groove of a bottom wall that seals an assembled mouth by pulling up a pull ring. In the inner plug, the anti-slip horizontal rib is erected on the inner peripheral surface portion of the pull ring where the fingertip for lifting is caught, in a posture inclined along the circumferential direction toward the extraction direction of the molding die. There is a thing.

  Since the horizontal rib is erected in an inclined manner toward the extraction direction of the molding die, that is, the inner core mold, it has a structure that is easily crushed elastically by the inner core mold when the inner core mold is extracted. By this crushing, the hooking at the time of “unreasonable” from the inner core mold is reduced.

  As described above, since the degree of catching at the time of "unreasonable" from the inner core mold is reduced, the protruding height can be increased to such an extent that the anti-slip action can be exhibited. .

  According to another configuration of the first invention of the present invention, in addition to the first main configuration described above, the protruding height of the lateral rib is substantially equal to the depth of the lateral rib forming die surface for molding the lateral rib. Is.

  If the protruding height of the horizontal rib is approximately equal to the depth of the horizontal rib forming mold surface that forms the horizontal rib, the horizontal rib can be caught by the fingertip when the pull ring is pulled up by the fingertip. As a result, the lateral rib exhibits a non-slip action.

  In addition to the first main configuration described above, another configuration of the first invention of the present invention is provided with a plurality of horizontal ribs in parallel.

  In the case where a plurality of horizontal ribs are provided in parallel, the anti-slip action can be enhanced by the increase in the number of horizontal ribs.

  The second main configuration of the present invention is a mold for molding the inner peripheral surface of the pull ring, and the lateral groove-shaped lateral rib molding die surface formed in the lateral rib molding mold part has a substantially equal groove width. In addition, the mold surface portion is inclined to the die cutting direction side, and the die surface portion on the die cutting direction side is configured to have a cross-sectional structure inclined at an acute angle with respect to the die cutting direction.

  Since the horizontal rib forming die surface has substantially the same groove width and is inclined toward the mold drawing direction side, the molded in-mold horizontal rib is entirely formed on the inner core mold drawing direction side. Molded in an inclined posture.

  For this reason, at the time of extraction of the inner core mold, the in-mold horizontal rib receives a crushing force toward the extraction direction side and the pull ring main body side by the horizontal rib forming mold surface while being caught by the inner core mold.

  At this time, the side surface on the inclined side of the in-mold horizontal rib, that is, the side surface on the side in the extraction direction of the inner core mold, is a space between the tilted inner rib and the pull ring main body due to the displacement of the inner core mold. Form.

  For this reason, this space becomes a “relief allowance” for the in-mold lateral rib that is being crushed, and the in-mold lateral rib is smoothly collapsed and collapsed.

  Since the pull ring main body portion where the “relief allowance” is formed is a portion where the in-mold lateral rib is not formed at all, the pressed in-mold lateral rib can be easily elastically depressed and thereby deformed. The in-mold lateral rib is retracted from being caught with the inner core mold.

  Another configuration of the second invention of the present invention is that, in addition to the second main configuration described above, the lateral rib mold surface is gently depressed at the open end of the lateral rib mold surface on the side opposite to the mold release direction. The skirt type surface part to be formed is formed.

  In the case where the hem mold surface part that gently sinks the horizontal rib molding die surface is formed, the degree of crushing action against the inner rib in the mold by the inner core mold can be weakened by the initial catch, and thereby the mold The crushing deformation of the inner lateral rib can be achieved smoothly.

Since the present invention has the above-described configuration, the following effects can be obtained.
In the first invention of the present invention, since the lateral rib has a structure that is easily elastically crushed by the inner core mold, the hook at the time of `` unreasonable '' from the inner core mold is reduced, As a result, it is possible to reduce the occurrence of unauthorized deformation in “shaving” by the inner core mold.

  Further, since the protruding height of the lateral rib can be increased to such an extent that the anti-slip action can be exerted, it becomes easy to obtain a pull ring having a high anti-slip effect.

  If the protruding height of the lateral rib of the first invention is substantially equal to the depth of the lateral rib forming mold surface for molding the lateral rib, the lateral rib can be reliably caught on the fingertip. The lateral ribs exhibit a sufficient anti-slip action, and thereby a stable pull-up pulling operation can be obtained.

In the first invention in which the plurality of lateral ribs are provided in parallel, the anti-slip action can be enhanced, and a reliable pull-up pulling operation can be obtained.

  In the second invention of the present invention, when the inner core mold is extracted, a “relief allowance” is formed on the side of the in-mold lateral rib in the direction of extraction. As a result, the lateral rib in the mold is retracted from the catch with the inner core mold, so that the lateral rib can be formed with less shaving, thereby providing a desired anti-slip lateral rib. Can be molded stably.

  In the second aspect of the present invention, in which the hem mold surface portion that gently sinks the lateral rib forming mold surface is formed, it is possible to smoothly achieve crushing deformation of the in-mold lateral rib. More stable molding of the lateral rib to be exhibited can be obtained.

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

  The pull-open inner plug 1 (refer to FIG. 1 hereinafter) is an integrally molded product that is injection-molded with polypropylene resin or low-density polyethylene resin. Is provided with a cylindrical pouring tube 11 whose diameter is expanded upward via an inner flange-shaped top wall 9 at the upper end of the assembled tube 7 to be undercut coupled by the above, and a spout is formed at the lower end of the pouring tube 11 The bottom wall 5 is opened continuously, the extraction cylinder 11 is surrounded, and a locking cylinder 10 having a low height is installed upright, and a lid (not shown) is locked and assembled when the lid is closed. On the lower surface of the top wall 9, a seal cylinder that is tightly fitted into the shed is provided.

  A thin loop-shaped fracture groove 6 is formed on the lower surface of the bottom wall 5 to define a spout opening location, and a pull ring that is pulled up when the spout is opened is formed on the upper surface of the bottom wall 5 inside the fracture groove 6. 2 are integrally provided via a support column 4.

  Three protrusion-shaped anti-slip horizontal ribs 3 are provided in parallel along the circumferential direction on the inner peripheral surface of the pull ring 2 where the fingertips are hooked. 3), the vertical cross-sectional shape has a substantially constant protruding height and is inclined in the direction of extraction of the inner core mold (not shown).

  The protruding height of the horizontal rib 3 is set to be approximately the same as the protruding height of the horizontal rib 3 that can exhibit the anti-slip effect.

  Therefore, when pulling up the pull ring 2 with the fingertip, the lateral rib 3 is hooked on the fingertip with a hooking force corresponding to the protruding height, and exhibits an anti-slip action.

  The lateral rib molding die surface 13 (refer to FIG. 4 hereinafter) formed in the inner core mold lateral rib molding die portion 12 has a rectangular lateral groove shape whose longitudinal cross-sectional shape is inclined toward the extraction direction side of the inner core mold. Therefore, the side surface on the extraction direction side is inclined at an acute angle with respect to the molding surface of the inner peripheral surface of the pull ring 2, and the open edge on the anti-extraction direction side is a skirt shape that sinks gently. A surface portion 14 is formed.

  The lateral rib forming die surface 13 having the lateral groove shape is formed with a depth substantially equal to the protruding height of the lateral rib 3 that can exhibit an anti-slip action.

  The in-mold lateral rib 3a injection-molded in the state shown in FIG. 5 is in a “forced removal” state with respect to the lateral rib molding die 12 as shown in FIG. 6 by extracting the inner core mold. Since the die surface of the horizontal rib forming die surface 13 on the extraction direction side is inclined at an acute angle, a space is formed on the extraction direction side of the in-die horizontal rib 3a due to the extraction displacement of the horizontal rib forming mold portion 12.

  This space is a portion where the in-mold lateral rib 3a to be crushed by the lateral rib molding die portion 12 can be positioned so as to fall down, so that it functions as a clearance allowance S. ”So that the crushing deformation of the in-mold lateral rib 3a is facilitated.

  In particular, the portion of the pull ring 2 where the clearance allowance S is formed is not a portion where the in-mold lateral rib 3a is protruded, and therefore is not compressed elastically deformed. The in-mold lateral rib 3a portion positioned at the portion is pushed into the pull ring 2 without undergoing large shaving deformation.

  Further, since the bottom mold surface portion 14 is formed at the open edge of the lateral rib molding die surface 13 on the side opposite to the extraction direction, the lateral rib molding for the in-mold lateral rib 3a is performed during the extraction operation of the lateral rib molding die portion 12. The catch of the mold part 12 is prevented from increasing rapidly.

  The in-mold lateral rib 3a is deformed into the lateral rib 3 due to the scraping action at the time of “unreasonable removal”. The degree of deformation is that the in-mold lateral rib 3a is inclined in the extraction direction. Since the clearance allowance S is formed, the lateral rib 3 having a large protruding height can be formed.

  As described above, the technology relating to the pull ring of the present invention makes it possible to give a desired protruding height to a portion that requires forced punching, and is widely used for applying the forced punching technology. Expansion can be expected.

It is a whole longitudinal cross-sectional view which shows one embodiment of this invention. It is a principal part expansion longitudinal cross-sectional view of a pull ring. FIG. 3 is a detailed sectional view further enlarging the main part of FIG. 2. It is an expansion longitudinal cross-sectional view of a horizontal rib shaping die part. It is an expanded sectional view which shows the shaping | molding state of an in-mold horizontal rib. FIG. 10 is an enlarged explanatory view of a “forced removal” forming operation of the lateral rib. It is explanatory drawing which shows the conventional horizontal rib. It is explanatory drawing which shows the modification of the conventional horizontal rib. It is explanatory drawing which shows another modification of the conventional horizontal rib.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Pull-open inside plug 2; Pull ring 3; Horizontal rib 3a; In-mold horizontal rib 4; Post 5; Bottom wall 6; Breaking groove 7; Assembly cylinder 8; 11; pouring cylinder 12; horizontal rib molding die 13; horizontal rib molding die surface 14; skirt die surface S; clearance allowance

Claims (5)

The pull ring in which the fingertip for pulling up is caught in the pull-open plug that forms the opening by breaking and removing the portion surrounded by the breaking groove of the bottom wall that seals the assembled mouth by pulling up the pull ring A synthetic resin pull-open inner plug in which an anti-slip horizontal rib is erected on the inner peripheral surface portion of the inner wall surface in a posture inclined along the circumferential direction toward the drawing direction of the molding die. 2. The synthetic resin pull-open inner plug according to claim 1, wherein the protruding height of the horizontal rib is substantially equal to the depth of the horizontal rib forming die surface for forming the horizontal rib. The synthetic resin pull-open inner plug according to claim 1 or 2, wherein a plurality of lateral ribs are provided in parallel. The horizontal groove-shaped horizontal rib forming mold surface formed in the horizontal rib forming mold portion of the mold for forming the inner peripheral surface of the pull ring has a substantially equal groove width and is inclined to the die-cutting direction side. In addition, a mold for forming a pull-open plug having a cross-sectional structure in which a die surface portion on the die-cutting direction side is inclined at an acute angle with respect to the die-cutting direction. 5. The pull-opening middle plug molding die according to claim 4, wherein a hem mold surface portion for gently sinking the horizontal rib molding die surface is formed at an open end portion of the lateral rib molding die surface on the side opposite to the mold release direction.

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