JP5316940B2 - Synthetic resin housing - Google Patents

Description

  The present invention has a synthetic resin casing, in particular, a body having a high shape retaining property, and when the inside is in a reduced pressure state, the reduced pressure is absorbed by the depressed deformation of the bottom wall of the bottom. The present invention relates to a synthetic resin casing.

  Conventionally, polyethylene terephthalate (hereinafter referred to as PET) resin biaxially stretched blow-molded casings, so-called PET bottles, have excellent transparency, mechanical strength, heat resistance, gas barrier properties, etc., and are used for various beverages. Widely used as a container. Conventionally, there is a so-called high-temperature filling method for filling a PET bottle with content liquids such as fruit juices and teas that require sterilization, and the contents liquid is filled into the casing at a temperature of about 90 ° C. Then, the cap is sealed and then cooled, and the inside of the housing is in a considerably reduced pressure state.

For this reason, for applications involving high-temperature filling as described above, a so-called reduced pressure absorption panel, which is a region that can be easily deformed by depression, is formed in the body part, and this reduced pressure absorption panel is used during pressure reduction. By deforming into a depressed shape, it maintains a good appearance and secures rigidity as a casing in parts other than the vacuum absorption panel so that there are no troubles in the transport line of the chassis, stacked storage, vending machines, etc. In other words, a so-called reduced pressure absorption function is exhibited.
Japanese Patent Laid-Open No. 08-048322

  On the other hand, when it is necessary to avoid the formation of the vacuum absorption panel on the body due to the design requirements related to the appearance of the housing, or the vacuum absorption panel itself is a part that is easily bent and deformed, In applications where surface rigidity must be increased to provide high shape retention to the body, a vacuum absorption function can be achieved by forming a depression in the bottom wall of the bottom without forming a vacuum absorption panel on the body. Use a synthetic resin casing.

  FIG. 6 shows that when the surface rigidity of the wall of the body part 4 is increased by the circumferential groove rib 7 and the inside is depressurized, the depressed part 11 of the depressed part 11 of the bottom part 5 exerts a reduced pressure absorption function. It is an example of the synthetic resin casing made to do.

  However, in the case of the type shown in FIG. 6, the wall thickness of the bottom wall is not necessarily uniform, and the reversal deformation gradually proceeds during decompression. As shown in the bottom view of FIG. 7B, the folds 18 are formed unevenly while forming a number of folds 18.

  Once the fold 18 is formed as described above, even if the cap is opened and the reduced pressure state is eliminated, the fold 18 becomes a hindrance and the depressed portion 11 can be sufficiently restored from the depressed deformation state. In addition, the liquid level of the content liquid (referred to as “entrance line” in the industry) does not drop sufficiently, so that there is a problem that the content liquid leaks outside when used with the cap removed. .

  In order to solve the above-mentioned problems in the prior art, the present invention provides a housing that exhibits a reduced pressure absorption function by a depression deformation accompanied by a reversal deformation of the depression portion at the bottom. It is an object to create a bottom wall structure that can be sufficiently restored from a deformed state.

Of the means for solving the above problems, the main configuration of the present invention is as follows.
A biaxial stretch blow molded synthetic resin casing,
Formed on the bottom surface of the bottom, with the inner peripheral edge of the grounding part provided around the periphery as the base, allowing the wall to be deformed inward during decompression, with the bottom wall recessed into the interior of the housing With a depressed part
The depressed portion includes a depressed peripheral wall portion standing upright from the vicinity of the inner peripheral edge of the ground contact portion at the peripheral portion, a depressed concave portion formed in a dome shape at the central portion, and an upper end portion of the depressed peripheral wall portion. Connecting the base end of the recess, and having a flat ring-shaped inverted wall portion formed so as to be able to be inverted and deformed with a gentle convex shape toward the outside of the housing ,
Furthermore, it is said that the peripheral rib wall portion that exhibits the function as the peripheral rib is disposed at the connecting portion between the upper end portion of the depressed peripheral wall portion and the inversion wall portion.

  The casing having the above-described structure is configured to exhibit a reduced pressure absorption function by the depression-like deformation of the bottom wall of the bottom, and when the casing is in a reduced pressure state, the inverted wall portion is inverted and deformed. As a result, the depressed part is further depressed and deformed in the direction of the inside of the housing, and exhibits a reduced pressure absorption function.

  In such a type of housing, as described above, the depression deformation in the depression does not progress uniformly over the entire circumference, and it progresses unevenly while forming several folds, Even if this crease becomes an obstacle and the decompression state is eliminated by removing the cap, there arises a problem that it cannot be sufficiently restored from the depressed deformation state.

Therefore, in the main configuration described above, by arranging a peripheral rib wall portion that exhibits a function as a peripheral rib at the connection portion between the upper end portion of the depressed peripheral wall portion and the inversion wall portion,
The peripheral rib wall prevents the above-described crease formation from progressing to the peripheral edge, and when the decompressed state is eliminated, the peripheral rib wall elastically restores to the reversal wall during decompression. It is possible to sufficiently restore the depressed portion from the depressed deformation state while eliminating the broken line.

  Here, the peripheral rib wall portion disposed on the connecting portion between the upper end portion of the depressed peripheral wall portion and the reversing wall portion can be formed in various modes, for example, a flat ring-shaped ring-shaped flat portion, a peripheral groove Further, a configuration in which a circumferential step portion is formed can be employed.

  According to another configuration of the present invention, a plurality of radial ribs are formed radially from the recessed portion toward the peripheral portion in addition to the main configuration described above.

The number of formations and formation positions of folds accompanying non-uniform reversal deformation of the reversal wall during decompression are not constant depending on the wall thickness distribution of the bottom wall and the progress of decompression, etc. It differs for each use mode.
Therefore, the above configuration is for making the number of formations and formation positions of the folds constant. For example, by arranging three radial ribs radially at equal central angles, in particular, the inversion wall portion. The folds formed in the radial direction can be specified as the three folds formed in the region from the tip of the radial rib to the peripheral rib wall, and a constant depression is possible regardless of the individual casings. As a deformation amount, a constant reduced pressure absorption function can be exhibited.

  Still another configuration of the present invention is a round casing in which a plurality of circumferential groove ribs are formed in a cylindrical body in addition to the above main configuration.

  With the above configuration, by forming a plurality of circumferential groove ribs on the cylindrical body, the surface rigidity of the body is increased to provide high shape retention, and a vacuum absorbing panel is formed on the body during decompression. It is possible to provide a round casing capable of exhibiting a reduced pressure absorption function with the bottom.

Since the present invention has the above-described configuration, the following effects can be obtained.
In the casing having the main configuration of the present invention, in the casing that exhibits the reduced pressure absorption function by the depression deformation accompanied by the reverse deformation of the bottom wall of the bottom,
The peripheral rib wall prevents the formation of folds to the peripheral edge, and when opening the cap, the elastic ribs restore elastically when the cap is opened. However, the depressed portion can be sufficiently restored from the depressed deformation state.

  In the case where a plurality of radial ribs are formed radially from the recessed portion toward the peripheral portion, the number of formations and the positions of the folds can be made constant, and a constant depressed deformation is possible regardless of the individual housing. As an amount, a certain reduced pressure absorption function can be exhibited.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below along the examples with reference to the drawings.
FIG. 1 shows a first embodiment of a synthetic resin casing according to the present invention, wherein (a) is a front view and (b) is a bottom view. This housing 1 is a biaxial stretch blow-molded product made of PET resin having a mouth tube part 2, a shoulder part 3, a cylindrical body part 4, and a bottom part 5 and having a capacity of 350 ml.

  The body portion 4 is formed with three circumferential groove ribs 7 to increase the surface rigidity and to have high shape retention. A bottom portion 5 is continuously provided at the lower end of the body portion 4 via a heel wall portion 19 formed in a curved cylindrical shape. A grounding portion 16 is provided around the periphery of the bottom surface of the bottom portion 5. Yes.

  Further, the bottom portion 5 is formed with a depressed portion 11 by causing the bottom wall to be depressed toward the inside of the housing 1 with the inner peripheral end of the grounding portion 16 as a base end. When the inside of the housing 1 is in a decompressed state, the recessed portion 11 is further recessed and deformed toward the inside of the housing 1 to exhibit a reduced pressure absorption function.

The detailed configuration of the depressed portion 11 is as follows.
That is, the depressed portion 11 includes a depressed peripheral wall portion 15 that is provided in the peripheral portion so as to stand upright from the vicinity of the inner peripheral end of the grounding portion 16, a depressed concave portion 12 that is formed in a dome shape at the central portion, and a depressed peripheral wall. Formed from a plate ring-shaped reversal wall 13 connecting the upper end of the portion 15 and the base end of the recessed recess 12;
Further, a flat and ring-shaped ring-shaped flat portion 14a, which is an embodiment of the peripheral rib wall portion 14 that functions as a peripheral rib, is formed at the connection portion between the upper end portion of the depressed peripheral wall portion 15 and the reversal wall portion 13. I am doing so.
Here, the inversion wall portion 13 is formed in a gently convex shape toward the outside of the housing so that it can be inverted and deformed in the inside of the housing.

FIG. 2 shows a state in which the depressed portion 11 is deformed when the housing 1 in FIG. 1 is filled with the content liquid at high temperature and sealed with the cap 21 and the inside of the housing is in a decompressed state. ) Is a front view, and (b) is a bottom view.
In FIG. 2A, from the state of FIG. 1 indicated by a two-dot chain line, the inversion wall portion 13 is inverted and deformed in the inner direction of the housing 1, and as a result, the depressed portion 11 becomes the housing 1 as indicated by an arrow. Depressed and deformed in the inner direction of the, and exerts a reduced pressure absorption function.
At this time, the liquid level Lf rises to a height position immediately below the lower end of the mouth tube portion 2 with the depression deformation of the depression portion 11.

  Here, the thickness of the bottom wall of the housing 1 is not necessarily uniform, and the reversal deformation gradually proceeds at the time of decompression. Therefore, the reversal deformation of the reversal wall portion 13 does not proceed uniformly over the entire circumference. While the folds 18 are formed, the process proceeds unevenly in an uneven shape, and finally the state shown in the bottom view of FIG.

The formation mode of the fold line 18 shown in FIG. 2 (b) is an example, and it appears in different modes depending on the individual casings or the progressing speed of the decompression, but is common in the following points. It has a form.
That is, several folds 18r (5 in the present embodiment) radially extend in the radial direction to the inner peripheral end of the ring-shaped flat portion 14a that functions as a peripheral rib, and adjacent folds. A fold 18p appears in the circumferential direction so as to connect the contact points of the 18r ring-shaped flat portion 14a with the inner peripheral end.
It should be noted that the region surrounded by the adjacent radial fold 18r (for example, the region cross-hatched in FIG. 2B) inside the circumferential fold 18p is greatly subject to the inverted reversal deformation of the reversal wall 13. It corresponds to the developed area.

  Then, when the cap 21 is opened from the state of FIG. 2 and the inside of the casing 1 is changed from the reduced pressure state to the normal pressure, the ring-shaped flat portion 14a is broken by the action effect as the peripheral rib, that is, the elastic restoring deformation action. The eye 18 is restored to a flat shape, that is, the crease 18 is eliminated, the reversal wall 13 is restored to the reverse shape, and the depression 11 is restored to the original shape shown in FIG. The surface Lf is lowered.

Here, FIG. 3 shows a variation of the peripheral rib wall portion 14 that exhibits the function as the peripheral rib, and is a longitudinal front view showing the vicinity of the bottom portion 5 in an enlarged manner.
1A is a ring-shaped flat portion 14a similar to the case 1 in FIG. 1, FIG. 1B is a circumferential groove 14b, and FIG. 1C is a circumferential step portion 14c, both of which are formed in a reduced pressure state. The function which eliminates 18 can be exhibited effectively.

  Next, FIG. 4 shows a second embodiment of the synthetic resin casing according to the present invention. Compared with the casing of the first embodiment shown in FIG. The third embodiment is characterized in that three radial ribs 17 are formed at equal central angular positions, and the structure of the other parts is the same as that of the casing of the first embodiment.

  FIG. 5 shows a state in which the depressed portion 11 is deformed when the housing 1 in FIG. 4 is filled with the content liquid at a high temperature and sealed with the cap 21 and the inside of the housing is in a decompressed state. ) Is a front view, and (b) is a bottom view. From the state of FIG. 4 indicated by a two-dot chain line, the depressed portion 11 is depressed and deformed in the inner direction of the housing 1 as indicated by an arrow, and the decompression absorbing function is Demonstrate.

  Here, the effect of forming the radial ribs 17 in the second embodiment is shown in the bottom view of FIG. 5B. By forming the radial ribs 17, the radial folds 18r can be formed. The region from the tip of the radial rib 17 to the inner peripheral end of the ring-shaped flat portion 14a can be specified, that is, the number of formations and formation positions of the folds 18r, 18p can be made constant regardless of individual casings, Regardless of the individual housing, it is possible to achieve a constant depression deformation amount, that is, to exhibit a constant decompression absorption function.

  Then, when the cap 21 is opened from the state of FIG. 5 and the inside of the housing 1 is changed from the reduced pressure state to the normal pressure, the ring-shaped flat portion 14a is broken due to the action effect as the peripheral rib, that is, the elastic restoring deformation action. While the eye 18 is restored to a flat shape, the inversion wall portion 13 is restored to the inversion shape, the depressed portion 11 is restored to the original shape shown in FIG. 4, and the liquid level Lf is lowered.

  Next, FIG. 6 shows a conventional synthetic resin casing. Compared with the casing of the first embodiment shown in FIG. 1, a peripheral rib is formed at the connecting portion between the depressed peripheral wall portion 15 and the inverted wall portion 13. There is no provision of the ring-shaped flat portion 14a that exhibits the function as described above, and the upper end of the depressed peripheral wall portion 15 and the inversion wall portion 13 are directly connected.

  FIG. 7 shows the state of the depression deformation of the depression 11 when the enclosure 1 of FIG. 6 is sealed with a cap 21 and the inside of the enclosure is in a reduced pressure state, (a) is a front view, (b) ) Is a bottom view, and in FIG. 6 (a), the inverted wall portion 13 is inverted and deformed in the inner direction of the housing 1 from the state of FIG. 11 is depressed and deformed in the inner direction of the housing 1 and exhibits a reduced pressure absorption function. And the liquid level Lf rises with this depression deformation.

  At this time, as in the case of the first embodiment, the wall thickness of the bottom wall is not necessarily uniform, and the reversal deformation gradually proceeds at the time of decompression. While forming a number of folds 18 without proceeding uniformly, it progresses unevenly in an uneven shape, and finally, as shown in the bottom view of FIG. Several (four in this embodiment) folds 18r extend to the upper end of the depressed peripheral wall 15 and the peripheral folds 18r and the upper end of the depressed peripheral wall 15 are connected to each other. A fold 18p appears in the direction.

8A and 8B show an example of a deformation mode of the depressed portion 11 when the cap 21 is removed from the state shown in FIG. 7, and FIG. 8A is a front view and FIG. 8B is a bottom view. In addition, even when opened, the ring-shaped flat that exhibits the function as a peripheral rib, that is, the function of restoring the fold 18 portion to a flat shape by an elastic restoring deformation action as in the case of the first embodiment. Since the peripheral rib wall portion 14 such as the portion 14a is not formed, the crease 18 remains as it is, the depressed portion 11 hardly recovers from the depressed deformation state, and as a result, the liquid level Lf does not decrease. The problem of leaking will occur.
Of course, there are various degrees of restoration from the depressed deformation state depending on the individual enclosures, but as a whole, sufficient restoration is not allowed.

  As mentioned above, although the structure of this invention and its effect were demonstrated along the Example, embodiment of this invention of this invention is not limited to the said Example.

  The synthetic resin casing of the present invention is a bottom wall that exhibits a reduced pressure absorption function at the bottom without forming a reduced pressure absorption panel in the body portion, and can be sufficiently restored from the depressed deformation state accompanying the reduced pressure. It is a housing having a structure that can be used with confidence, and can be used in a wider area in the bottle field that requires high-temperature filling.

(A) which shows 1st Example of the housing of this invention is a front view, (b) is a bottom view. (A) which shows the deformation | transformation aspect of the bottom wall at the time of pressure reduction of the housing of FIG. 1 is a front view, (b) is a bottom view. It is explanatory drawing which shows the variation of a surrounding rib wall part. (A) which shows 2nd Example of the housing of this invention is a front view, (b) is a bottom view. FIG. 5A is a front view and FIG. 5B is a bottom view showing a deformation mode of the bottom wall during decompression of the housing of FIG. 4. (A) which shows the housing of a prior art example is a front view, (b) is a bottom view. (A) which shows the deformation | transformation aspect of the bottom face at the time of pressure reduction of the housing of FIG. 6 is a front view, (b) is a bottom view. (A) which shows the deformation | transformation aspect of a bottom face at the time of opening a cap from the state of FIG. 7 is a front view, (b) is a bottom view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Housing 2; Mouth part 3; Shoulder part 4; Trunk part 5; Bottom part 7; Circumferential groove rib 11; Depression part 12: Depression recessed part 13; Inverted wall part 14: Peripheral rib wall part 14a; 14b; peripheral groove 14c; peripheral step portion 15; depressed peripheral wall portion 16; ground contact portion 17; radial ribs 18 (18r, 18p); fold 19; heel wall portion 21; cap Lf;

Claims (6)

A biaxially stretched blow-molded synthetic resin housing with the bottom surface of the bottom (5) and the inner periphery of the grounding portion (16) provided around the periphery as the base end. A recessed portion (11) formed by allowing the bottom wall to be recessed toward the inside of the housing so as to be capable of being deformed in a recessed direction, and the recessed portion (11) has a peripheral portion of the grounding portion (16). A depressed peripheral wall portion (15) provided upright from the vicinity of the inner peripheral edge, a depressed concave portion (12) formed in a dome shape at the center, and an upper end portion and a depressed portion of the depressed peripheral wall portion (15) The base end portion of the recess (12) is connected, and has a flat ring-shaped inverted wall portion (13) formed so as to be capable of being inverted and deformed with a gentle convex shape toward the outside of the housing , and A synthetic resin casing having a structure in which a peripheral rib wall portion (14) that functions as a peripheral rib is disposed at a connecting portion between the upper end portion of the depressed peripheral wall portion (15) and the reversal wall portion (13).
Annular ring like flat portion in flat connecting part of the upper portion and the inverted wall portion (13) of the depression peripheral wall (15) forming a (14a), the circumferential rib wall (14) and claims 1, wherein Synthetic resin housing.
Upper portion and the connecting portion to form a peripheral groove (14b) of the inversion wall (13), the circumferential rib wall (14) and claims 1 synthetic resin bottle body according depressed wall portion (15).
The synthetic resin casing according to claim 1, wherein a peripheral step portion (14c) is formed at a connection portion between the upper end portion of the depressed peripheral wall portion (15) and the reversal wall portion (13) to form a peripheral rib wall portion (14).
The synthetic resin casing according to claim 1, 2, 3 or 4, wherein a plurality of radial ribs (17) are formed radially from the depressed recess (12) toward the peripheral edge. The synthetic resin casing according to claim 1, 2, 3, 4 or 5, wherein the casing is a round casing in which a plurality of circumferential groove ribs (7) are formed on a cylindrical body (4).

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