JP4725889B2 - Synthetic resin housing - Google Patents

Description

  The present invention is a synthetic resin casing, in particular, a biaxially stretched portion made of a synthetic resin, which has a body portion having high shape retention, and generates a reduced pressure inside after filling and sealing the content liquid. It relates to the structure of the bottom of the housing.

  In the case of a synthetic resin case in which a reduced pressure is generated inside after filling and sealing with the content liquid, the reduced pressure generated in the inside is absorbed so that unauthorized deformation due to the reduced pressure does not occur in the case.

This reduced pressure absorption function part is formed as a part that is easily depressed and deformed in a constant form due to reduced pressure, and is formed separately from the other part on the trunk or bottom of the housing. Sink deformation prevents the appearance of the body from appearing unnatural.
Japanese Patent Laid-Open No. 08-048322

  Among these reduced pressure absorption function parts, those formed on the body of the casing are conspicuous as the appearance of the casing, so if you dislike this, or the reduced pressure absorption function part itself is a part that tends to bend and deform. When it is desired to impart high shape retention to the body, it is necessary to provide a reduced pressure absorption function part only at the bottom of the housing.

  The decompression absorption function part of the bottom part disclosed in the above prior art has a structure in which the cylindrical wall of the conical cylinder located inside the grounding surface part of the bottom part has a bellows wall structure. The depressurized displacement at the bottom absorbs the reduced pressure inside the housing.

  However, in the above-described prior art, the decompression absorption function part at the bottom part has only a simple bellows wall structure, so that it can be displaced downward as in the case of the depression displacement into the housing. For this reason, there is a problem that there is a risk that the bottom center portion may protrude downward due to the weight of the filled content liquid.

  In the case of a biaxially stretched blow molded casing, the center part of the bottom part is an unstretched part, which is a thicker part than the other part, and the part close to the center part of the bottom part is also sufficient. Since it is a portion that is formed relatively thick by not being stretched, there is a problem that there is no guarantee that the molded bellows-like reduced pressure absorbing function portion can be properly stretched and deformed.

  Therefore, the present invention was devised to solve the above-described problems in the prior art, and the central portion of the bottom portion having the internal pressure resistance is maintained in a state in which the shape and posture thereof are substantially constant. It is a technical problem to absorb the decompression in the body by sinking into the torso, and while maintaining a stable self-supporting function, a stable and reliable decompression absorption action is obtained, and a large decompression absorption capacity is obtained. The purpose is to demonstrate.

  The biaxially-stretched blow molded synthetic resin casing of the present invention provides high shape retention to the cylindrical barrel, and the bottom portion connected to the lower end of the barrel is located in the center. A wall portion, a flat wall portion located outside the depressed wall portion, a leg wall portion located outside the flat wall portion to form a ground contact surface, and a trunk portion located outside the leg wall portion The heel wall part which forms the connection part with is comprised.

  At the boundary between the bottom leg wall portion and the flat wall portion, there is a circumferential groove that sinks into the body portion, and at least the inversion wall portion formed by the inner wall portion of the circumferential groove is generated at the reduced pressure. Therefore, it can be reversed and deformed.

  The body portion is formed as a cylindrical body having a sufficiently high shape retaining property by molding with a large wall thickness or applying appropriate reinforcing means.

  The depressed wall portion at the bottom is formed in a dome shape, the flat wall portion is a substantially flat ring plate shape, and the heel wall portion connecting the leg wall portion and the trunk portion is the leg wall. It has a curved wall structure that curves and rises from the head toward the body.

  The reversing wall portion is composed of the inner wall portion of the circumferential groove that is recessed in the trunk portion, and a large pressure reduction is applied to the inner portion composed of the recessed wall portion and the flat wall portion that is located inside the reversing wall portion. When this works, the reversal wall portion is reversed and deformed, and the inner portion composed of the depressed wall portion and the flat wall portion is depressed and displaced in the body portion, thereby exerting a large reduced pressure absorbing action.

  This decompression and absorption action causes the inner portion of the depressed wall portion and the flat wall portion located inside the leg wall portion to be depressed and displaced in the trunk portion, so that the leg wall portion is hardly deformed.

  Since the casing according to the present invention is a biaxially stretched blow-molded casing, the vicinity of the leg wall portion at the bottom is easy to form thinner than the other portions, but the inversion close to the leg wall portion. The wall portion can be specified and thinly formed easily by controlling the thickness of the preform, which is the primary molded product of the casing, in advance.

  Another casing of the present invention is provided with a plurality of transverse grooves that are radially located at equal central angles in a portion from the leg wall portion to the heel wall portion.

  The plurality of transverse grooves act as a general “split groove” for the cylindrical structure portion of the bottom peripheral edge portion where the leg wall portion is located, and thereby, from the depressed wall portion and the flat wall portion. When the inner part is displaced into the torso, the leg wall part slightly indents the inside, thereby facilitating the displacement of the inner part described above, and the reduced pressure exerted thereby. The amount of absorption is increased.

  Moreover, another casing of the present invention is such that the inverted wall portion is a portion extending from the inner wall portion of the circumferential groove to the flat wall portion.

  By extending the reversal wall part not only to the inner wall part of the circumferential groove but also to the flat wall part adjacent thereto, the reversal wall part itself can be easily subjected to reverse deformation, and the depressed wall part and the flat wall part It is possible to increase the amount of depression displacement of the inner part consisting of

  Further, another housing according to the present invention is a flat wall portion that accompanies the bending deformation of the reversal wall portion due to the weight effect of the content liquid between the lower surface that is the ground contact surface of the leg wall portion and the lower surface of the flat wall portion. Steps larger than the descending displacement dimension are provided.

  Even if bending deformation occurs in the reversal wall part due to the weight of the content liquid by making the step larger than the downward displacement dimension of the flat wall part due to the bending deformation of the reversal wall part due to the weight effect of the content liquid, The lower surface of the flat wall portion is not positioned lower than the lower surface of the leg wall portion, whereby the stable “seat” function of the leg wall portion can be exhibited.

  Therefore, a stable self-supporting function of the housing can be obtained from the time when the content liquid is filled to the time when it is sealed with the cap, and when the decompression disappears after opening.

  Further, another housing of the present invention is provided with a plurality of reinforcing ribs that are radially located at equal central angles on the depressed wall portion.

  By providing a plurality of reinforcing ribs on the recessed wall, it is possible to increase the heat resistance and internal pressure resistance of the recessed wall, thereby deforming the inverted wall with insufficient mechanical strength from the recessed wall side. The adverse effects of force can be almost eliminated.

  Another casing of the present invention has a cylindrical body portion in which a plurality of reinforcing circumferential grooves are provided in parallel.

  The barrel portion is cylindrical, and a plurality of reinforcing circumferential grooves are provided in parallel to constitute the barrel portion, whereby the barrel portion can be effectively reinforced, thereby improving the shape retention of the barrel portion. .

Since the present invention has the above-described configuration, the following effects can be obtained.
In the case of the present invention, the inner part consisting of the recessed wall part and the flat wall part located in the center part of the bottom part is recessed and displaced in the trunk part, thereby exerting a reduced pressure absorption action, so that a large reduced pressure The amount of absorption can be obtained reliably.

Further, the reduced pressure absorption action is to cause the inner portion of the depressed wall portion and the flat wall portion located inside the leg wall portion to be depressed and displaced in the trunk portion, so that the leg wall portion is hardly deformed. Thus, even if the reduced pressure absorption action is exhibited, the “seat” by the leg wall portion is stably maintained.

  In the part from the leg wall part to the heel wall part that is provided with a plurality of transverse grooves that are radially located at equal central angles, the plurality of transverse grooves act as a general “split groove”. In addition, it is easy to cause the depression displacement of the inner part composed of the depressed wall portion and the flat wall portion, and the reduced pressure absorption amount to be exhibited is increased, so that a large reduced pressure absorption amount can be obtained smoothly. .

  In the case where the inversion wall portion is a portion extending from the inner wall portion of the circumferential groove to the flat wall portion, the inversion wall portion is not only the inner wall portion of the circumferential groove but also the flat wall portion adjacent thereto. By extending to the part, the reversal wall part itself can be easily reversed and the amount of depression displacement of the inner part consisting of the depression wall part and the flat wall part can be increased. You can get action.

  A step larger than the downward displacement dimension of the flat wall portion is provided between the lower surface, which is the ground contact surface of the leg wall portion, and the lower surface of the flat wall portion, due to the bending deformation of the inverted wall portion due to the weight effect of the content liquid. For example, even if the reversal wall portion is bent and deformed due to the weight of the content liquid, the lower surface of the flat wall portion is not positioned lower than the lower surface of the leg wall portion. The stable "seat" function of the housing can be exhibited, and the stable self-standing function of the housing is obtained during the period from filling the content liquid to sealing with the cap and when the decompression disappears after opening. Therefore, safe and stable handling of the housing can be obtained.

  When the recessed wall is provided with a plurality of reinforcing ribs that are radially located at equal central angles, the heat resistance and internal pressure resistance of the recessed wall can be improved, and the mechanical strength is sufficient. Therefore, the adverse effect of the deformation force from the recessed wall portion side on the non-inverted wall portion can be almost eliminated, and a stable decompression absorption operation by the invertible wall portion can be obtained.

  In the case where a plurality of reinforcing circumferential grooves are provided in parallel to the cylindrical body, the body can be effectively reinforced, thereby improving the shape retention of the body, Therefore, the stable grip handling by the hand of the housing can be obtained.

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

  FIG. 1 is an overall front view showing a first embodiment of a biaxially-stretched blow molded synthetic resin casing according to the present invention. The casing is a cylindrical body portion 11 whose lower end is closed by a bottom 1. A mouth tube portion 14 provided with a thread and a neck ring on the outer peripheral surface thereof is connected to the upper end of the sleeve through a shoulder portion 13.

  In this case, the body 11 as a main part of the container is formed with a sufficient thickness, or a plurality of (in the illustrated example, six) reinforcing circumferential grooves 12 are formed as in the illustrated embodiment. By being arranged side by side, it has a sufficiently high shape retention in appearance.

  A bottom portion 1 (see FIGS. 2 and 3) connected to the lower end of the trunk portion 11 is located at the center, and has a dome-like depression wall portion 2 depressed in the trunk portion 11, and the depression wall portion 2. A flat ring-plate-like flat wall portion 5 provided continuously at the outer peripheral end via a stepped portion 4 having an enlarged diameter, and a peripheral groove 6 recessed in the body portion 11 at the outer peripheral end of the flat wall portion 5. A flat ring plate-like leg wall portion 8 continuously provided, and an outer peripheral end of the leg wall portion 8 and a lower end of the trunk portion 11, and a heel wall formed into a curved and rising cylindrical shape. Part 9.

  On the lower surface (inner surface) of the recessed wall portion 2, a plurality (six in the illustrated example) of reinforcing ribs 3 are provided radially at equal central angles, and the reinforcing ribs 3 are integrally provided. The recessed wall portion 2 can be given a relatively large stretch, and the heat resistance and internal pressure resistance of the recessed wall portion 2 can be improved.

  The step portion 4 and the flat wall portion 5 are portions that prevent the internal stress generated during biaxial stretch blow molding from affecting the leg wall portion 8 in the combined portion of the recessed wall portion 2 and the reinforcing rib 3. Also, it is a portion that elastically receives the internal pressure acting on the bottom 1.

  The circumferential groove 6 is provided around the boundary between the leg wall portion 8 and the flat wall portion 5, but between the lower surface (grounding surface) of the leg wall portion 8 and the lower surface of the flat wall portion 5. Since there is a step d, the inner wall portion of the circumferential groove 6 is smaller in height than the outer wall portion by this step d, and the inner wall portion having a smaller height width is the inverted wall. Part 7 is formed.

  The reversal wall portion 7 is thinned to such an extent that it can be reversed and deformed. The reversal wall portion 7 is formed by forming a primary molded product that is biaxially stretch blow molded into a casing. When this is done, this temporary molded product is achieved by molding it in a preset form with thickness control.

  When the decompression in the housing is increased, the reversal wall portion 7 is inversely elastically deformed by the decompression force with the bottom portion of the substantially circumferential groove 6 as a base point, and as shown in phantom lines in FIG. The reinforcing rib 3, the stepped portion 4 and the flat wall portion 5) are depressed and displaced in the body portion 11, and the reduced pressure generated by the depressed displacement is absorbed.

  Moreover, this inversion wall part 7 is not restrict | limited to the inner wall part of the circumferential groove 6, The outer peripheral end part of the flat wall part 5 connected to this inner wall part is shape | molded thinly, and this circumferential groove A portion from the inner wall portion of 6 to the outer peripheral end portion of the flat wall portion 5 may be the reverse wall portion 7.

  The step d formed between the leg wall portion 8 and the flat wall portion 5 is deformed by the reversal wall portion 7 due to the weight effect of the content liquid, and is displaced downward by the deformation deformation of the reversal wall portion 7. It is formed to a value larger than the displacement dimension of the flat wall portion 5 so that the leg wall portion 8 exhibits a stable grounding function.

  Further, when the inner wall portion of the circumferential groove 6 is the reversal wall portion 7 and the outer wall portion of the circumferential groove 6 is configured not to be the reversal wall portion 7, the reversal wall portion 7 is a flat wall. The part 5 is hardly deformed in the direction in which it is displaced downward, so that the step d can be set to the same level (about 0.5 mm) as the step in the case where general decompression occurs.

  4 and 5 show a second embodiment of the housing according to the present invention, in which a transverse groove 10 is added to the bottom 1 of the first embodiment shown in FIGS. It is.

  Eight transverse grooves 10 are provided in a portion from the leg wall portion 8 to the heel wall portion 9 radially and at equal central angles, and a cylindrical portion formed by the leg wall portion 8 and the heel wall portion 9 is formed. Acts as a "groove".

  That is, by providing the transverse groove 10, the portion from the leg wall 8 to the heel wall 9 is easily elastically deformed slightly while being guided by the transverse groove 10, and thereby the inversion wall portion. 7 can be smoothened, and the amount of reduced pressure absorption obtained can be increased by the amount of deformation of the portion from the leg wall 8 to the heel wall 9.

  In addition, since the portion from the leg wall portion 8 to the heel wall portion 9 is slightly elastically deformed by the crossing groove 10, an inversion wall is formed on the portion from the leg wall portion 8 to the heel wall portion 9. Since the deformation force accompanying the reverse deformation of the portion 7 does not concentrate and distributes substantially evenly by the transverse groove 10, even if elastic deformation occurs in the leg wall portion 8, this leg wall portion 8 proper grounding function is maintained.

It is a whole front view showing the example of the first embodiment of the present invention. FIG. 2 is an enlarged vertical sectional view of a bottom portion of the first embodiment example shown in FIG. 1. It is an expanded bottom view of the bottom part of the example of 1st embodiment shown in FIG. It is a whole front view which shows the example of 2nd embodiment of this invention. It is a bottom view of the bottom part of the example of 2nd embodiment shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Bottom part 2; Recessed wall part 3; Reinforcement rib 4; Step part 5; Flat wall part 6; Circumferential groove 7; Inverted wall part 8; Leg wall part 9; Heel wall part 10; Reinforcing circumferential groove 13; shoulder 14; mouth tube part d;

Claims (6)

  After filling and sealing the content liquid, a biaxially stretched blow-molded synthetic resin casing in which reduced pressure is generated inside, the bottom part connected to the lower end of the cylindrical body having high shape retention, A dome-shaped recessed wall portion located in the center and recessed in the body portion, a flat wall portion having a substantially flat ring plate shape located outside the recessed wall portion, and located outside the flat wall portion. A leg wall portion that is connected to the trunk portion via a heel wall portion that rises with a curved outer peripheral end, and is surrounded by a boundary portion between the leg wall portion and the flat wall portion. A synthetic resin casing in which a groove is provided and at least an inverted wall portion constituted by a wall portion inside the circumferential groove is formed so as to be capable of being inverted and deformed.   The synthetic resin casing according to claim 1, wherein a plurality of transverse grooves are provided in a portion from the leg wall portion to the heel wall portion so as to be radially arranged at equal central angles.   The synthetic resin casing according to claim 1 or 2, wherein the reverse wall portion is a portion extending from the inner wall portion of the circumferential groove to the flat wall portion.   A step larger than the downward displacement dimension of the flat wall portion is provided between the lower surface, which is the ground contact surface of the leg wall portion, and the lower surface of the flat wall portion, due to the bending deformation of the reversal wall portion due to the weight effect of the content liquid. The synthetic resin casing according to any one of claims 1 to 3.   The synthetic resin casing according to any one of claims 1 to 4, wherein a plurality of reinforcing ribs that are radially located at equal central angles are provided on the depressed wall portion.   The synthetic resin casing according to any one of claims 1 to 5, wherein a plurality of reinforcing circumferential grooves are provided in parallel in the cylindrical body portion.

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