JP6537770B2 - Plastic bottle - Google Patents

Description

  The present invention relates to plastic bottles.

  Plastic bottles (hereinafter, also simply referred to as "bottles") are widely used as bottles for beverages, and weight reduction thereof is required. As a method of reducing the weight of the bottle, it is common to make the wall thinner, but at the same time the thinning leads to a decrease in the strength of the bottle. Therefore, when designing a bottle, it is required to balance the contradictory elements of weight reduction and strength maintenance.

  In particular, bottles filled with contents such as beverages are required to be able to withstand a large top load (longitudinal compression load). In other words, when transporting and storing bottles, it is stored in a cardboard box in units of several to dozens of containers filled with the contents, or put together in a shrink pack or a binding band, etc. and stacked on a pallet Therefore, each lower bottle must be able to withstand a large top load.

  For this reason, efforts have been made to achieve both weight reduction and strength maintenance by devising the shape of the bottle. Specifically, the strength has been improved by forming an annular concave rib on the barrel of the bottle, and studies are being made to maintain the normal shape even when top load is applied. (See Patent Document 1).

JP, 2011-116427, A

  In response to recent rising awareness of resource saving, plastic bottles are required to be thinner. For this reason, it is difficult to meet the demand for further thinning by a method of improving the strength by devising the shape of the bottle as in the prior art and resisting the top load while maintaining the shape of the bottle at the normal time. There is.

  Therefore, the inventor of the present application tried to solve the above-mentioned problems by an approach completely different from the conventional one. That is, instead of maintaining the shape of a normal bottle, it was considered to resist top load by crushing a predetermined amount of the bottle filled with contents in the longitudinal direction.

  Specifically, first, for example, prior to storage in a cardboard box, the bottle is subjected to a relatively small top load, and the bottle shoulder is deformed so as to sink into the bottle barrel. Then, the bottle is to be stored in a cardboard box for transportation / storage with the depression state. The bottle stored in the cardboard box in this way is taken out of the cardboard box at the retailer or the like to which it is transported, and then the bottle shoulder which has been sunk so far is pulled out from the inside of the bottle body to form a normal bottle shape. It can be restored. That is, by deforming (sinking) the bottle in advance during transportation / storage, the bottle can be made to withstand the top load at the time of stacking cardboard boxes, and by being restored to a normal bottle shape after transportation, It becomes possible to store it in the shop as usual and to use it for drinking.

  However, the inventor of the present application found a new problem here. That is, when top load was applied to the bottle prior to storage in the cardboard box, a phenomenon was observed that a large depression was locally generated at the bottle shoulder, and the entire bottle shoulder did not become uniform. . As a result, the bottle opening above the bottle shoulder is inclined, and can not withstand the top load when stacking cardboard boxes, or stress concentrates on a part of the bottle shoulder, resulting in breakage, etc. There was a problem that the commodity value was greatly reduced.

  The present invention has been made in view of the above backgrounds, and the object thereof is to make it possible to sink and restore a thin plastic bottle without damaging the bottle shoulder and to be effective against top load. It is to provide a plastic bottle that can cope with

In order to achieve the above object, the plastic bottle of the present invention is a bottle which expands downward so as to connect a bottle mouth serving as a pouring spout of contents, a bottle barrel, the bottle mouth and the bottle barrel. A shoulder portion and a plastic bottle having the same, wherein the bottle shoulder portion has a first circumferential rib, a second circumferential rib and a third circumferential rib which are annular in order from the upper side on the same axis as the bottle opening. And, when a top load acts on the plastic bottle, the plastic bottle is deformed starting from the first circumferential rib, the second circumferential rib, and the third circumferential rib to shift to a depressed state in which the plastic bottle is depressed downward; drawable configured after the top load is released are also configured to be capable of maintaining the depressed state, from the depressed state to allow further restored after release of the top load upward It is what is.

  According to the present invention, for example, by applying a top load to the plastic bottle prior to storage in the cardboard box, a compressive load is applied to the bottle shoulder, and the first circumferential rib, the second circumferential rib and the third circumferential rib The bottle shoulder can be deformed from the point of origin to the state of depression. In this case, since the first circumferential rib, the second circumferential rib and the third circumferential rib are all annular in shape coaxial with the bottle opening, the bottle shoulder is deformed so as to be uniformly depressed about the bottle opening Do. Therefore, it is possible to cause the bottle shoulder to buckle due to a compressive load without tilting the bottle opening and to shift to the depressed state, and the stress generated on the bottle shoulder at the time of the transition is the first circumference Since the ribs, the second circumferential rib and the third circumferential rib are dispersed, it is possible to suppress local stress concentration and breakage due to it.

  In addition, in the plastic bottle that has been shifted to the depressed state, when top load is further applied, a tensile load is applied to the bottle shoulder which is sunk in the bottle barrel. For this reason, it is possible to endure, for example, a large top load when cardboard boxes are stacked in a stable shape.

  Preferably, the bottle shoulder has a first diameter rib extending radially from the bottle opening toward the bottle barrel, between the first circumferential rib and the second circumferential rib. Between the second circumferential rib and the third circumferential rib, it is preferable to have a second diameter rib radially extending from the bottle port side toward the bottle body.

  According to this configuration, the bottle shoulder is deformed so as to be folded back along the first diameter rib and the second diameter rib, and the plastic bottle is shifted to the depressed state by preventing the inclination of the bottle opening more reliably. Can.

  Preferably, the first radial rib and the second radial rib may be arranged to be circumferentially shifted about the bottle opening in top view.

  According to this configuration, when the plastic bottle is shifted to the depressed state, the transmission of the stress generated in the first diameter rib and the second diameter rib is suppressed, and the stress concentration and the breakage in the bottle shoulder portion are more reliably suppressed. It is possible to

  Preferably, the bottle barrel may have a pressure absorbing surface that deforms so as to expand with the transition of the bottle shoulder to the depressed state.

  According to this configuration, the pressure rise inside the plastic bottle can be absorbed by the bulging of the pressure absorbing surface when the plastic bottle is deformed to the depression state. Therefore, for example, when top load is applied prior to storage in a cardboard box, it becomes possible to reduce the reaction force (force acting on the inside of the plastic bottle from the inside of the plastic bottle) caused by the increase in internal pressure. The shoulder can be stably depressed to prevent inclination of the bottle mouth, and transition to a depressed state that can withstand the top load when stacking cardboard boxes can be made.

It is a perspective view of the plastic bottle concerning a 1st embodiment. It is a front view of the plastic bottle of FIG. It is a top view of the plastic bottle of FIG. Fig.4 (a) is an enlarged view around the shoulder part of the plastic bottle of FIG. 1, FIG.4 (b) is the half end view cut | disconnected by XX of FIG. 4 (a). Fig.5 (a) is the expansion perspective view seen from each of the upper surface side and front side about the state before the deformation | transformation of the plastic bottle of FIG. 1, FIG.5 (b) is the state in the plastic bottle of FIG. It is an expansion perspective view seen from each of the upper surface side and the front side, and Drawing 5 (c) is an enlarged perspective view seen from each of the upper surface side and the front side about a state after modification of a plastic bottle of FIG. 6 (a) is an enlarged perspective view of a state of an initial deformation of the plastic bottle of FIG. 1, and FIG. 6 (b) is an enlarged perspective view of a state where the deformation of the plastic bottle of FIG. (C) is an enlarged perspective view of the plastic bottle of FIG. 1 after deformation. It is an expansion perspective view around a shoulder of a plastic bottle concerning a 2nd embodiment. It is a top view of the plastic bottle of FIG. Fig.9 (a) is an enlarged view around the shoulder part of the plastic bottle of FIG. 7, FIG.9 (b) is the semi-end surface figure cut by the YY line | wire of FIG. 9 (a). It is an expansion perspective view around a shoulder of a plastic bottle concerning a 3rd embodiment. It is a top view of the plastic bottle of FIG. 12 (a) is an enlarged view around the shoulder of the plastic bottle of FIG. 10, and FIG. 12 (b) is a half end view cut along the line Z-Z of FIG. 12 (a). FIG. 13 (a) is a perspective view of a plastic bottle according to the fourth embodiment, and FIG. 13 (b) is an enlarged perspective view around the shoulder of the plastic bottle of FIG. 13 (a). Fig. 14 (a) is a perspective view of a plastic bottle according to a fifth embodiment, and Fig. 14 (b) is an enlarged perspective view around the shoulder of the plastic bottle of Fig. 14 (a).

A plastic bottle according to a preferred embodiment of the present invention will be described with reference to the attached drawings.
In the following description, the side with the mouth of the bottle is the upper side, and the side with the bottom of the bottle is the lower side. The cross-sectional shape means a cross-sectional shape in a plane perpendicular to the central axis of the bottle.

First Embodiment
As shown to FIGS. 1-4, the plastic bottle 1 (henceforth "the bottle 1") has the opening 2, the shoulder 3, the trunk | drum 4, and the bottom 5 in an order from an upper side. These parts (2, 3, 4 and 5) are integrally formed and constitute a bottomed cylindrical bottle wall for storing the beverage therein. As a beverage, it is suitable for storing non-carbonated beverages such as water, green tea, oolong tea, blended tea, sports drinks or fruit juice. In addition, the bottle 1 is suitable for a large-sized bottle having a capacity of more than 1 liter, and here, for example, 2 liters is used, but the present invention is not limited to this, 1 liter It can also be applied to less than bottles.

The bottle 1 is formed by, for example, a stretch molding method such as biaxial stretch blow molding, using a thermoplastic resin such as polyethylene, polypropylene or polyethylene terephthalate as a main material.
An example of the manufacturing process of the bottle 1 will be described. First, a thermoplastic resin is injected into a mold, and a preform is injection molded. The preform is composed of a mouth having the same shape as the mouth 2 and a bottomed cylindrical portion connected to the lower side of the mouth. After injection molding, the preform is set in a blow molding machine, and the tubular portion of the preform is heated. Then, the tubular portion is stretched in the longitudinal direction by the stretch rod, and compressed air is blown to stretch the tubular portion in the lateral direction. The stretched cylindrical portion is pressed against the inner surface of the mold and then solidified. Thereby, the shoulders 3, the body 4 and the bottom 5 are formed, and a series of forming of the bottle 1 is completed.

  As shown in FIG. 4, the upper end of the mouth 2 is open and functions as a pouring spout of a beverage. The opening of the mouth 2 is opened and closed by attaching and detaching the cap 21. The shoulder 3 gradually widens in cross section downward. That is, the shoulder 3 expands downward so as to connect the opening 2 with the smallest diameter in the bottle 1 to the upper end of the body 4 constituting the maximum width in the bottle 1. Moreover, the ridgeline connecting the shoulder 3 and the upper end of the trunk 4 is a substantially sinusoidal curve extending alternately and repeatedly the ridges 12 and the valleys 14 in the circumferential direction. Specifically, the top of the peak 12 is located at the middle of one side of the square, and the top of the valley 14 is located at the corner of the square, corresponding to the square cross-sectional shape of the body 4.

  The body 4 is a square tubular portion having a square cross-sectional shape as a basis. More specifically, as shown in FIG. 3, in the square cross-sectional shape of the body 4, four square corners 31 are arcs, and a straight line portion 33 is provided between adjacent corners 31, 31. Further, as shown in FIG. 1 and FIG. 2, the body 4 has a constricted portion 40 and a depressed portion 80 for finger insertion in the middle in the vertical direction. As shown in FIG. 2, when the trunk 4 is divided into three areas in the vertical direction, the trunk 4 has a constriction 40, an upper trunk 42 above the constriction 40, and a lower side of the constriction 40. And the lower torso portion 44. The upper body 42 and the lower body 44 are portions having a square cross-sectional shape which is constant in the vertical direction. In the upper body portion 42 and the lower body portion 44, a plurality of continuous grooves 50 and a plurality of intermittence grooves 52 extending in the circumferential direction are alternately formed in the vertical direction. Further, as shown in FIG. 4, a pressure absorbing surface 16 recessed toward the inside of the bottle 1 is respectively formed on the upper side surface of the upper body portion 42. The shapes of the mouth 2, the body 4 and the bottom 5 are not particularly limited, and can be designed as appropriate.

  The shoulder portion 3 has a plurality of first blocks 331 annularly arranged around the mouth 2 and a plurality of second blocks 332 annularly arranged on the outer periphery of the plurality of first blocks 331. . The first block 331 and the second block 332 are formed by projecting a preform from the inside to the outside of the bottle 1 and have a substantially square shape in top view. By arranging the first block 331 and the second block 332 in an annular manner as described above, a first circumferential rib, which is an annular groove surrounding the periphery of the opening 2, is formed between the opening 2 and the first block 331. A second circumferential rib 312, which is an annular groove surrounding the first circumferential rib 311, is formed between the first block 331 and the second block 332. Furthermore, on the outer peripheral side of the second block 332, a third peripheral rib 313 which is an annular groove surrounding the outer periphery of the second peripheral rib 312 is formed. The first circumferential rib 311, the second circumferential rib 312, and the third circumferential rib 313 can also be viewed as steps or bent portions formed in the shoulder 3 having a substantially truncated conical shape.

  End portions 331a to 331c of the first block 331 are formed substantially in a straight line. Further, the second block 332 is also formed in a substantially linear shape at its end portions 332a to 332c. Therefore, the first circumferential rib 311, the second circumferential rib 312, and the third circumferential rib 313 formed at the end of the first block 331 and the second block 332 respectively have a circle centered on the opening 2 in top view A plurality of grooves having linear ridge lines in contact with the ring form an annular shape.

  Further, since the plurality of first blocks 331 are annularly arranged at predetermined intervals, the first diameter ribs 321 are formed between the end portions 331 b and 331 b of the adjacent first blocks 331 and 331. Similarly, the second diameter rib 322 is formed between the end portions 332b, 332b of the adjacent second blocks 332, 332. Each of the first diameter rib 321 and the second diameter rib 322 is a groove extending radially from the mouth 2 side toward the trunk 4 side. Further, as shown in FIG. 3, the first diameter rib 321 and the second diameter rib 322 are arranged to be shifted by an angle θ in the circumferential direction centering on the mouth 2 in top view.

  The deformation (sinking) of the bottle 1 of the present embodiment described above will be described.

  As shown in FIG. 5, when a top load (vertical compression load) is applied to the upper surface of the cap 21 attached to the mouth 2 in the direction indicated by the arrow F (vertically downward), the force is applied to the mouth 2 Through the shoulder 3. As described above, since the first circumferential rib 311, the second circumferential rib 312, and the third circumferential rib 313 are formed on the shoulder portion 3 coaxially with the mouth portion 2, the cross-sectional shape of the bottle 1 changes Stress concentration occurs at these sites.

  The plurality of first blocks 331 formed between the first circumferential rib 311 and the second circumferential rib 312 due to the stress concentration, and the plurality formed between the second circumferential rib 312 and the third circumferential rib 313 A compressive load acts on the second block 332 of FIG. The compression load causes the first block 331 and the second block 332 to bend, resulting in an unstable shape. As a result, when buckling occurs in the first block 331 first, as shown in FIG. 5B, the first circumferential rib 311 and the second circumferential rib 312 are deformed as a starting point, and the plurality of first blocks 331 Fold back along the second circumferential rib 312 and sink downward. The adjacent first blocks 331 and 331 folded downward are also folded back to the opening 2 side so as to approach each other from the first diameter rib 321 formed between them.

  As the shoulder portion 3 sinks inwards, the pressure inside the bottle 1 rises. This pressure rise causes the pressure absorbing surface 16 to bulge outward. Thereby, the rise in the internal pressure of the bottle 1 is absorbed.

  Even after being deformed as shown in FIG. 5B, when the top load is continuously applied, the first circumferential rib 311 and the second circumferential rib 312 are provided to the plurality of first blocks 331 folded downward. The tensile load acts between the On the other hand, a compressive load continues to act on the plurality of second blocks 332 between the second circumferential rib 312 and the third circumferential rib 313. When the second block 332 is bent due to this compressive load and buckling occurs, as shown in FIG. 5C, the second circumferential rib 312 and the third circumferential rib 313 are deformed as a starting point, as shown in FIG. The two blocks 332 fold back along the third circumferential rib 313 and sink downward. The adjacent second blocks 332, 332 folded downward are also folded back toward the mouth 2 so as to approach each other from the second diameter rib 322 formed therebetween.

  The depressed state of the bottle 1 in the depressed state shown in FIG. 5 (c) is maintained even after releasing the top load that has been operated. In the bottle 1 in such a depressed state, when a top load further acts, a tensile load is generated in any of the plurality of first blocks 331 and second blocks 332, so that no buckling occurs and stability is achieved. Can resist top load.

  In this bottle 1, for example, the top load is applied to the bottle 1 prior to storage in a cardboard box to shift from the normal state shown in FIG. 5 (a) to the depressed state shown in FIG. 5 (c). Transported and stored in a cardboard box with the condition of depression. As a result, even when cardboard is stacked on the pallet, the bottle 1 in the lower cardboard box has a large top load due to the reaction force against the tensile load and the reaction force based on the internal pressure rising with the depression. Can withstand.

  Since the first circumferential rib 311, the second circumferential rib 312 and the third circumferential rib 313 are all annular grooves coaxial with the mouth 2, the shoulder 3 centers the mouth 2 when transitioning to the depressed state It deforms to sink uniformly as. That is, it is possible to shift to the depression state without tilting the mouth 2 and to be in a state capable of withstanding the top load when the cardboard boxes are stacked.

  Further, by pulling out from the inside of the body 4 the shoulder 3 that has been sunk in the retail store or the consumer at the transport destination, it is possible to restore it to a normal bottle shape. That is, by deforming (sinking) the bottle in advance during transportation / storage, the bottle can be made to withstand the top load at the time of stacking cardboard boxes, and by being restored to a normal bottle shape after transportation, It becomes possible to store it in the shop as usual and to use it for drinking.

  Each of the first circumferential rib 311, the second circumferential rib 312, and the third circumferential rib 313 exhibits an annular shape by a plurality of continuous grooves having linear ridge lines in contact with a circle centered on the opening 2 in top view. ing. Therefore, it is possible to deform the shoulder portion 3 when the top load is applied prior to storage in the cardboard box so as to fold back along the straight ridge line of the groove. Therefore, compared with the case where the ridge line of the annular groove is curved, the inclination of the opening 2 can be prevented more surely, and the state can be shifted to a depressed state that can withstand the top load when piled up cardboard boxes. .

  Furthermore, the rise of the internal pressure of the bottle 1 is absorbed by the expansion of the pressure absorption surface 16, so that when the top load is applied prior to the storage in the cardboard box, the reaction force generated by the increase of the internal pressure is It is possible to reduce. Therefore, the shoulder portion 3 can be stably depressed to prevent inclination of the mouth portion 2, and the state can be shifted to a depressed state that can withstand the top load when the cardboard boxes are stacked.

  Then, with reference to FIG. 6, the result of numerical analysis regarding deformation (dent) and stress when top load is applied to the bottle 1 will be described. Here, a numerical analysis model of the bottle 1 was created using a general-purpose program, and structural analysis using the finite element method was performed to evaluate deformation and stress occurring in the bottle 1. The thickness of the numerical analysis model of the bottle 1 reproduces the variation due to the part although it is minute as in the plastic bottle manufactured by the actual injection molding. Assuming that the top load acts with the bottle 1 placed on a desk and the shoulder 3 is depressed, the numerical analysis model of the bottle 1 restrains the bottom and loads the cap 21 with a vertically downward load. Boundary conditions were set to operate.

  In the numerical analysis model of the bottle 1, as shown in FIG. 6 (a) to FIG. 6 (c), even if the top load acts, a state in which the shoulder 3 collapses with the mouth 2 hardly inclined I understand. This is because the shoulder portion 3 of the bottle 1 is deformed so as to be folded back along the ridge line of the groove, and the first diameter rib 321 and the second diameter rib 322 are offset in the circumferential direction, so that the first diameter It is considered that the stress transfer and stress concentration along the rib 321 and the second diameter rib 322 did not occur. As a result, the shoulder 3 of the bottle 1 model is restrained from local deformation, and is uniformly sunk while maintaining the symmetry.

Second Embodiment
Next, with reference to FIGS. 7-9, the plastic bottle 1A (henceforth "the bottle 1A") which concerns on 2nd Embodiment is demonstrated. The shape of the periphery of the shoulder portion of the bottle 1A is different from that of the bottle 1, and the same configuration is appropriately denoted by the same reference numeral, and the description thereof is omitted.

  In the shoulder 3A of the bottle 1A, a first circumferential rib 311A which is an annular groove surrounding the periphery of the opening 2 and a second circumferential rib 312A which is an annular groove which surrounds the first circumferential rib 311A are formed in top view Ru. Furthermore, a third circumferential rib 313 which is an annular groove surrounding the outer periphery of the second circumferential rib 312 is formed. That is, the shoulder 3 </ b> A has a first circumferential rib 311 </ b> A, a second circumferential rib 312 </ b> A and a third circumferential rib 313 coaxially with the mouth 2. Each of the first circumferential rib 311A, the second circumferential rib 312A, and the third circumferential rib 313A can also be regarded as a stepped portion or a bent portion formed in the shoulder portion 3 having a substantially truncated cone shape.

  The shoulder 3A of the bottle 1A has no protrusion such as a first block 331 and a second block 332 around the mouth 2 like the bottle 1 described above. For this reason, the first circumferential rib 311A, the second circumferential rib 312A and the third circumferential rib 313A do not have linear ridges, and as shown in FIG. 7, a circle centered on the opening 2 in top view It is annularly formed.

  In the bottle 1A configured as described above, stress concentration occurs first along the first circumferential rib 311A, the second circumferential rib 312A, and the third circumferential rib 313A by the action of the top load. Then, a compressive load acts on a portion between the first circumferential rib 311A and the second circumferential rib 312A and a portion between the second circumferential rib 312A and the third circumferential rib 313A in the shoulder portion 3A. Local buckling occurs. Thereby, the bottle 1A can be shifted to a depressed state in which the upper part of the third circumferential rib 313A is depressed inward.

Third Embodiment
Next, a plastic bottle 1B (hereinafter referred to as "bottle 1B") according to a third embodiment will be described with reference to FIGS. The shape of the periphery of the shoulder portion of the bottle 1B is different from that of the bottle 1, and the same reference numerals will be given to the same configuration as appropriate, and the description will be omitted.

  The shoulder 3B of the bottle 1B, like the bottle 1, includes a plurality of first blocks 331B annularly arranged around the mouth 2, and a plurality of first blocks 331B annularly arranged on the outer periphery of the plurality of first blocks 331B. It has two blocks 332B. The first block 331B has end portions 331Ba to 331Bc formed in a substantially linear shape. The second block 332B also has end portions 332Ba to 332Bc formed in a substantially linear shape. For this reason, the first circumferential rib 311B, the second circumferential rib 312B and the third circumferential rib 313B are each formed in an annular shape by a plurality of continuous grooves having linear ridge lines in contact with a circle centered on the opening 2 in top view. It is presenting.

  Further, by forming the first block 331B and the second block 332B, the bottle 1 is also formed in that the first circumferential rib 311B, the second circumferential rib 312B and the third circumferential rib 313B are formed in order from the mouth 2 side. Is the same as Furthermore, the first diameter rib 321B is formed between the end portions 331Bb and 331Bb of the adjacent first blocks 331B and 331B, and the first diameter rib 321B is formed between the end portions 332Bb and 332Bb of the adjacent second blocks 332B and 332B. The point in which the two-diameter rib 322 B is formed is also the same as the bottle 1.

  The bottle 1B differs from the bottle 1 in the arrangement of the first diameter rib 321B and the second diameter rib 322B. That is, as described above, while the first diameter rib 321 and the second diameter rib 322 of the bottle 1 are arranged by being shifted by an angle θ in the circumferential direction centering on the mouth 2 in top view (see FIG. 3 And the first diameter rib 321B and the second diameter rib 322B of the bottle 1B are arranged on the same straight line (see FIG. 11).

  The top load acts on the bottle 1B configured as described above, so that the shoulder 3B can be deformed so as to fold back along the straight ridge line of the groove. Since the first diameter ribs 321B and the second diameter ribs 322B are arranged on the same straight line, the stress is transmitted along the transition to the depressed state. In this case, it is possible to suppress stress concentration and local deformation and to sink uniformly while maintaining the symmetry by reducing the variation in thickness and the like.

Fourth Embodiment
Next, with reference to FIG. 13, a plastic bottle 1C (hereinafter, referred to as "bottle 1C") according to a fourth embodiment will be described. The shape of the periphery of the shoulder of the bottle 1C is different from that of the bottle 1, and the same configuration is given the same reference as appropriate, and the description thereof is omitted. Moreover, in FIG.13 (b), illustration of cap 21 periphery is abbreviate | omitted.

  The shoulder 3C of the bottle 1C is, like the bottle 1, a plurality of first blocks 331C annularly arranged around the mouth 2, and a plurality of first blocks 331C annularly arranged on the outer periphery of the plurality of first blocks 331C. It has two blocks 332C. The first block 331C has end portions 331Ca, 331Cb, and 331Cc formed in a substantially linear shape. The second block 332C has end portions 332Ca, 332Cb, and 332Cc formed in a substantially linear shape. Therefore, each of the first circumferential rib 311C, the second circumferential rib 312C, and the third circumferential rib 313C has an annular shape by a plurality of continuous grooves having linear ridge lines in contact with a circle centered on the opening 2 in top view. It is presenting.

  Further, by forming the first block 331C and the second block 332C, the bottle 1 is also formed in that the first circumferential rib 311C, the second circumferential rib 312C and the third circumferential rib 313C are formed in order from the mouth 2 side. Is the same as Furthermore, the first diameter rib 321C is formed between the end portions 331Cb and 331Cb of the adjacent first blocks 331C and 331C, and the first diameter rib 321C is formed between the end portions 332Cb and 332Cb of the adjacent second blocks 332C and 332C. The point in which the two-diameter rib 322C is formed is also the same as the bottle 1.

  The bottle 1C differs from the bottle 1 in the arrangement of the second diameter rib 322C. That is, in the bottle 1, the number of the second blocks 332 arranged is the same as the number of the first blocks 331, while in the bottle 1C, the number of the second blocks 332C arranged is 2 of the first block 331C. It has been doubled. Therefore, the number of the second diameter ribs 322C disposed on the shoulder 3C of the bottle 1C is twice as large as that of the bottle 1. Further, the first diameter rib 321C and the second diameter rib 322C of the bottle 1C are arranged to be aligned on the same straight line, and the bottle 1C has a plurality of pillars extending in the vertical direction inside the pressure absorbing surface 16C. It differs from the bottle 1 also in that the rib 16C1 of the

  The top load acts on the bottle 1 </ b> C configured as described above, so that the shoulder 3 </ b> C can be deformed so as to fold back along the straight ridge line of the groove. Since the first diameter ribs 321C and the second diameter ribs 322C are arranged on the same straight line, stress is transmitted along them in the transition to the depressed state. In this case, it is possible to suppress stress concentration and local deformation and to sink uniformly while maintaining the symmetry by reducing the variation in thickness and the like.

Fifth Embodiment
Next, a plastic bottle 1D according to the fifth embodiment (hereinafter, referred to as "bottle 1D") will be described with reference to FIG. The shape of the periphery of the shoulder portion of the bottle 1D is different from that of the bottle 1, and the same configuration is appropriately denoted by the same reference numeral, and the description thereof is omitted. Moreover, in FIG.14 (b), illustration of cap 21 periphery is abbreviate | omitted.

  Shoulder 3D of bottle 1D is formed so that slopes 331D and 332D which are a part of slopes of quadrangular pyramids which differ in size may be piled up, respectively. As a result, the first circumferential rib 311D, the second circumferential rib 312D and the third circumferential rib 313D having linear ridge lines are formed in a step-like manner around the slopes 331D and 332D so as to surround the mouth 2. Ru. Each of the first circumferential rib 311D, the second circumferential rib 312D, and the third circumferential rib 313D is formed in a rectangular ring shape with rounded corners.

  Also in the bottle 1D configured as described above, the top load acts to fold the shoulder 3D along the straight ridge of the step, thereby suppressing stress concentration and local deformation, and maintaining symmetry. It becomes possible to sink uniformly.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. That is, those to which those skilled in the art appropriately modify the design of these specific examples are also included in the scope of the present invention as long as they have the features of the present invention. For example, each element included in each specific example described above and its arrangement, material, conditions, shape, size, and the like are not limited to those illustrated, and can be appropriately changed. For example, the number of circumferential ribs (311, 312, 313) may be three or more. For example, if the head space can be made relatively large, the number of circumferential ribs may be increased to three or more. Moreover, the cross-sectional shape of the trunk | drum 4 can be made into a rectangle. In this case, at least one of the first circumferential rib 311, the second circumferential rib 312, and the third circumferential rib 313 may be formed into a flat annular shape, and further, an elliptical annular circumferential rib and a perfect circular annular circumferential rib It is also possible to combine various forms of circumferential ribs, such as a combination of Moreover, each element with which each embodiment mentioned above is equipped can be combined as much as technically possible, and what combined these is also included in the scope of the present invention as long as the feature of the present invention is included.

  1: Bottle (plastic bottle) 2: Mouth (bottle mouth) 3: Shoulder (bottle shoulder) 4: Torso (bottle barrel) 16: Pressure absorbing surface 311: First circumference Rib, 312: Second circumferential rib, 313: Third circumferential rib, 321: First diameter rib, 322: Second diameter rib

Claims (3)

A plastic bottle having a bottle mouth serving as a pouring spout of contents, a bottle body, and a bottle shoulder expanding downward so as to connect the bottle mouth and the bottle body,
The bottle shoulder has a first circumferential rib, a second circumferential rib and a third circumferential rib, which are annular grooves, in order from the upper side, coaxially with the bottle opening, and the top of the plastic bottle When the load acts, it shifts from the first circumferential rib, the second circumferential rib, and the third circumferential rib as a starting point and shifts downward to a depressed state, and the top load is released even after the top load is released. It is configured to be able to maintain a depressed state, and further configured to be able to be pulled upward from the depressed state so as to be able to be restored after the release of the top load ,
The plastic bottle, wherein the bottle body has a pressure absorbing surface that deforms so as to expand with the transition of the bottle shoulder to the depressed state . The bottle shoulder is
Between the first circumferential rib and the second circumferential rib, there is provided a first diameter rib radially extending from the bottle opening side toward the bottle barrel side,
The plastic according to claim 1, further comprising a second diameter rib radially extending from the bottle opening side toward the bottle barrel side between the second peripheral rib and the third peripheral rib. Bottle. The plastic bottle according to claim 2, wherein the first diameter rib and the second diameter rib are arranged to be circumferentially shifted around the bottle opening in top view.