JP4136998B2 - Blow molded body - Google Patents

Description

  The present invention relates to a blow molded article having a double wall panel structure in which reinforcing ribs are formed.

  Conventionally, in order to reinforce a blow molded article having a double wall panel structure composed of front and back panel walls and side peripheral walls surrounding the panel walls, ribs connecting the two panel walls are formed. As this type of rib, as described in the following Patent Documents 1 to 5, the rib extends continuously from one panel wall of the double wall panel structure toward the other panel wall, and is narrow on both side surfaces. A rib having a substantially trapezoidal cross-section formed by the top surface portion, and a vertically extending from one panel wall of the double-wall panel structure toward the other panel wall, and welded together to form a plate shape Ribbed ribs (so-called hidden ribs) are known. In addition, as described in Patent Documents 6 to 7 below, a rib is also known in which a reinforcing member is wrapped.

JP 2004-58286 A Japanese Patent Laid-Open No. 2003-165152 JP-A-6-71739 JP-A-6-179236 Japanese Patent Laid-Open No. 5-254002 Japanese Patent Laid-Open No. 11-188782 Japanese Patent Laid-Open No. 9-11323

These reinforcing ribs are generally formed along the length direction of the blow molded body, and if the blow molded body is a flat panel-shaped blow molded body having a substantially rectangular shape in plan view, it is arranged in a row parallel to either side or It is formed in multiple rows. However, such a blow-molded body is likely to warp or deform along the diagonal direction because of the long length in the diagonal direction, or when a load is applied to the center of the panel wall in the thickness direction. If the number of ribs is increased and the thickness of the blow molded body is increased, these warpage and deformation can be suppressed. However, this increases the weight of the product and increases the cost.
The present invention was made in view of this problem in the conventional panel-shaped blow molded article, and by devising the arrangement of the ribs, the rigidity of the panel is increased, and warpage and deformation along the diagonal direction are suppressed. Objective.

  The present invention relates to a blow-molded body having a double-wall panel structure having a substantially quadrangular shape in plan view and comprising a panel wall on the front and back sides and a side wall surrounding the four sides, and one panel wall and the other panel wall are connected in the vicinity of four corners. Reinforcing ribs are formed, extending from one panel wall continuously to the other panel wall in a substantially vertical direction, and the tip thereof being welded to the inside of the other panel wall. On the other hand, it is characterized in that it is formed in the shape of a small wall. In this blow molded article, not only a panel with a uniform thickness, but also, for example, a step composed of a thick outer peripheral frame part and a thin inner peripheral part is formed on the one panel wall which is substantially equal to the difference in thickness. And the rib formed in the location of the level | step difference is included.

In the blow-molded product, the rib may be a double-walled rib formed by both side surface portions continuous to the panel wall and a top surface portion at the tip thereof, or both side surface portions continuous to the panel wall are welded to each other. It is a hidden rib. These may be combined. The rib may extend substantially vertically from both panel walls toward the opposing panel wall, and both ends may be welded to each other at an intermediate position between the two panel walls.
Furthermore, in the blow molded article, the rib is preferably formed along a plane substantially perpendicular to a diagonal line connecting opposing corners. Further, it is desirable that the parting line is set at a location closer to the one panel wall than the center of the side wall.

In the case where the rib is composed of a double-walled rib composed of both side surface portions continuous to the panel wall and the top surface portion at the tip thereof, the top surface portion of the rib continuously extending from one panel wall is used as the other panel. It can also be kept in a position very close to the inside of the other panel wall without being welded to the wall. Alternatively, the top surface portions of the ribs continuously extending from both panel walls can be opposed to each other at positions very close to each other without being welded to each other. In this case, the initial rigidity of the panel is not strong compared with the case of welding, but when the panel is deformed by applying a load pushing the panel wall in the thickness direction, the top surface of the rib comes into contact with the other panel wall. Alternatively, the top surface portions of both ribs come into contact with each other, the subsequent rigidity is increased, and the same effect as that of the welded rib is achieved.
Moreover, the rib according to the present invention and a conventional rib can be freely applied to the blow molded body.

  The blow molded body of the double-wall panel structure according to the present invention has a rib that is formed in a shape that is thin with respect to the corner, so that the rigidity of the panel is particularly high and the panel wall is subjected to a load that pushes the panel wall in the thickness direction. It is strong against deformation, and in particular, can be prevented from being bent or deformed along the diagonal direction, and is suitable for use as, for example, a floor panel or a wall board.

Hereinafter, with reference to FIGS. 1-12, the blow molded object of the double wall structure which concerns on this invention is demonstrated concretely.
A blow molded body 1 shown in FIG. 1 is substantially rectangular in a plan view, and includes an outer peripheral frame portion 2 having a large thickness and an inner peripheral portion 3 having a small thickness. When the cross-sectional structure of the blow molded body 1 is examined in detail, as shown in FIGS. 1 and 2, a double wall composed of front and back panel walls (first panel wall 4 and second panel wall 5) and side peripheral walls 6 surrounding four sides. The first panel wall 4 has a first panel outer peripheral wall 7 and a first panel inner peripheral wall 8 having a step S in the vertical direction, and a first panel side wall 9 connecting the steps. The second panel wall 5 is a flat surface without a step, and the step S appears as a difference in thickness between the outer peripheral frame portion 2 and the inner peripheral portion 3.

A rib 11 is formed in the vicinity of each corner, and a rib 12 is formed in the center of each side at the level difference portion of the blow molded body 1. The rib 11 is formed long in a direction (indicated by a double-headed arrow X in FIG. 1) substantially perpendicular to a diagonal line (not shown) that connects opposite corners, and is arranged in a shape of a small corner for each corner. As shown in FIG. 3, the rib 11 extends vertically from the first panel wall 4 (the first panel outer peripheral wall 7 and the first panel inner peripheral wall 8) toward the second panel wall 5, and the tip thereof is the second panel wall. 5 is composed of side surface portions 11a and 11b continuous to the first panel wall 4 (the first panel outer peripheral wall 7 and the first panel inner peripheral wall 8) and a top surface portion 11c narrowed in a trapezoidal shape. The side wall 11 a forms part of the first panel side wall 9.
The rib 12 is formed long in a direction along a plane parallel to each side portion. As shown in FIG. 4, the rib 12 also extends from the first panel wall 4 (the first panel outer peripheral wall 7 and the first panel inner peripheral wall 8) toward the second panel wall 5, and the tip thereof is the second panel wall. 6 is composed of both side surface portions 12a and 12b continuous to the first panel wall 4 (the first panel outer peripheral wall 7 and the first panel inner peripheral wall 8) and a top surface portion 12c narrowed in a trapezoidal shape. The side wall 12a forms part of the first panel side wall 9.

  The blow molded body 1 is used, for example, as a container lid (the first panel wall 4 side is the back surface and the second panel wall 5 side is the surface). The rib 11 enhances the rigidity against bending along the diagonal direction of the panel, and the rib 12 enhances the rigidity against bending along the direction parallel to each side portion, thereby suppressing deflection and deformation with respect to the load from above. Further, the weight of the blow molded body 1 does not increase with the rigidity enhancement.

  5 and 6 show a part of the manufacturing process of the blow molded body 1, wherein 13 is a parison, and 14 and 15 are dies. The parting lines of the dies 14 and 15, that is, the parting lines of the blow molded body 1 are set closer to the first panel wall 5 than the center of the side peripheral wall 6 (the center position in the panel thickness direction). . Accordingly, the dies 14 and 15 first come into contact with the parison 13 at the location circled in FIG. 5, and the parison 13 is unlikely to be cooled and stretched at the location, so the location surrounded by the circle in FIG. Becomes the thickest and is relatively strengthened. By setting the parting line as described above, both side portions of the ribs 11 and 12 (in the vicinity of the top surface portions 11c and 12c) are strengthened, and at the same time, in the vicinity of the lower end of the side peripheral wall 6 (for example, the blow molded body 1 is covered with a lid). , The side of the first panel wall 4 becomes the back surface, that is, the lower side) is reinforced along the parting line, and the blow molded body 1 has the effect of increasing the rigidity against the load from above.

A blow molded body 21 shown in FIGS. 7 and 8 has a substantially rectangular shape in plan view, and is a double wall panel comprising front and back panel walls (first panel wall 24, second panel wall 25) and side peripheral walls 26 surrounding four sides. It has a structure and a uniform thickness as a whole. Ribs 31 are formed in the vicinity of each corner, and the ribs 31 are formed long in a direction substantially perpendicular to a diagonal line (not shown) connecting the opposite corners, and are arranged in a square shape with respect to each corner. ing.
As shown in FIG. 8, the rib 31 includes a first rib 32 and a second rib 33, and the first rib 32 extends vertically from the first panel wall 24 toward the second panel wall 25, and the first panel wall 24. It is a double-walled rib composed of both side surface portions 32a and 32b continuous to each other and a top surface portion 32c narrowed in a trapezoidal shape. The second rib 32 is a so-called hidden rib extending from the second panel wall 25 toward the first panel wall 24 and having both side surfaces 33a and 33b welded to each other to form a plate shape. The tips of the first rib 32 and the second rib 33 are welded together to constitute the rib 31.

  The blow molded body 21 is used as, for example, a floor panel or a wall board. The ribs 31 enhance the rigidity against bending along the diagonal direction of the panel, and suppress deflection and deformation with respect to the load from above. Further, the weight of the blow molded body 1 does not increase with the rigidity enhancement. If necessary, such ribs 31 may be formed parallel to each side.

The ribs 31 of the blow molded body 21 can be replaced with the ribs 41 and 51 having the forms shown in FIGS. The rib 41 includes a first rib 42 and a second rib 43, and the first rib 42 extends vertically from the first panel wall 44 toward the second panel wall 45, and is formed on both side surfaces 42 a that are continuous with the first panel wall 44. 42b and a top wall portion 42c narrowed in a trapezoidal shape, a double wall rib. The second rib 42 extends vertically from the second panel wall 45 toward the first panel wall 44, and is composed of both side surface portions 43a and 43b continuous to the first panel wall 45 and a top surface portion 43c narrowed in a trapezoidal shape. It is a double-walled rib. The tips of the first rib 42 and the second rib 43 are welded together to constitute the rib 41.
The rib 51 extends from the first panel wall 54 toward the second panel wall 55, and its tip is welded to the inner surface of the second panel wall 55. It is comprised by the top surface part 51c narrowed in trapezoid shape.

  In addition, when the rib consists of a 1st rib and a 2nd rib in the blow molded object 21, both can also be comprised by a hidden rib. Further, hidden ribs can be formed in the blow molded body 1 instead of the ribs 11 and 12.

FIG. 11 shows an example in which the top surface portion of the rib continuously extending from the first panel wall toward the second panel wall is not welded to the inside of the second panel wall, and FIG. An example in which the top surfaces of the ribs extending continuously from the second panel wall are not welded to each other will be described.
FIG. 11 shows the same cross section as FIG. 3 when the rib 11 not welded to the second panel wall 5 is formed in the blow molded body 1 shown in FIG. Used. The rib 11 extends vertically from the first panel wall 4 (the first panel outer peripheral wall 7 and the first panel inner peripheral wall 8) toward the second panel wall 5, and is narrowed in a trapezoidal shape on both side surfaces 11a and 11b. It is comprised by the surface part 11c, and the top surface part 11c has reached the position very close to the 2nd panel wall 5 (there is a clearance gap D between the panel walls 5). In this example, since the top surface portion 11c of the rib 11 is not welded to the second panel wall 5, there is an advantage that a welding mark (a trace of welding) does not appear on the outer surface of the second panel wall 5.

  FIG. 12 shows the same cross section as FIG. 9 when the first and second ribs are not welded to each other in the blow molded body 21 shown in FIG. The code is used. The rib 41 includes a first rib 42 and a second rib 43, and the first rib 42 extends vertically from the first panel wall 44 toward the second panel wall 45, and is formed on both side surfaces 42 a that are continuous with the first panel wall 44. 42b and a top surface portion 42c narrowed in a trapezoidal shape, and the second rib 42 extends vertically from the second panel wall 45 toward the first panel wall 44 and is continuous with the first panel wall 45. 43b and a top surface portion 43c narrowed in a trapezoidal shape, and both the top surface portions 42c and 43c are very close to each other (there is a gap D).

It is a perspective view of the blow molded object which concerns on this invention. It is AA sectional drawing. It is the BB sectional drawing. It is the CC sectional drawing. It is sectional drawing explaining the manufacturing method. It is sectional drawing explaining the manufacturing method similarly. It is a perspective view of the blow molded object which concerns on this invention. It is the DD sectional drawing. It is sectional drawing which shows the cross-sectional shape of another rib. It is sectional drawing which shows the cross-sectional shape of another rib. It is sectional drawing which shows the cross-sectional shape of another rib. It is sectional drawing which shows the cross-sectional shape of another rib.

Explanation of symbols

1, 21 Blow molding 2 Outer frame 3 Inner frame 4, 24, 44, 54 First panel wall 5, 25, 45, 55 Second panel wall 6 Side wall 11, 12, 31, 41, 51 Rib

Claims (8)

In a blow molded body of a double wall panel structure having a substantially quadrangular shape in a plan view and comprising a side wall surrounding the front and back panel walls and four sides, a reinforcement for connecting one panel wall and the other panel wall in the vicinity of four corners. ribs are formed, the ribs, in which its tip is welded to the inside of the other panel walls continuously from one panel wall extends substantially perpendicularly toward the other panel walls, sides continuous with the panel wall It is composed of a surface portion and a top surface portion at the tip thereof, and the ribs of the double wall where the both side surface portions are continuous at both ends in plan view, or the both side surface portions continuous to the panel wall are continuous at both ends in plan view and welded together to form a plate The blow molded body , which is a hidden rib, and is formed in a shape that is narrower than the corner. The blow-molded body is composed of an outer peripheral frame portion having a large thickness and an inner peripheral portion having a small thickness. A step substantially equal to the thickness difference is formed on the one panel wall, and the rib is formed at the position of the step. The blow molded article according to claim 1, wherein the blow molded article is provided. In a blow molded body of a double wall panel structure having a substantially quadrangular shape in a plan view and comprising a side wall surrounding the front and back panel walls and four sides, a reinforcement for connecting one panel wall and the other panel wall in the vicinity of four corners. Ribs are formed, the ribs extend substantially vertically from both panel walls to the opposing panel walls, and both ends are welded to each other at an intermediate position between the two panel walls. Consists of continuous side surfaces and a top surface at the tip thereof, and the both side surfaces are continuous double-walled ribs, or both side surfaces continuous to the panel wall are continuous at both ends in plan view and welded together. A blow-molded product characterized in that it is a plate-like hidden rib, and is formed in a small shape with respect to the corner portion. In a blow molded body of a double wall panel structure having a substantially quadrangular shape in a plan view and comprising a side wall surrounding the front and back panel walls and four sides, a reinforcement for connecting one panel wall and the other panel wall in the vicinity of four corners. Ribs are formed, the ribs extend substantially perpendicularly from one panel wall toward the other panel wall, and are composed of both side surface portions continuous to the one panel wall and the top surface portion of the tip thereof , Both side surface portions are double-walled ribs that are continuous at both ends in plan view , and the top surface portion is located close to the inside of the other panel wall, and is formed in the shape of a faint corner with respect to the corner. A blow molded article characterized by that. The blow-molded body is composed of an outer peripheral frame portion having a large thickness and an inner peripheral portion having a small thickness. A step substantially equal to the thickness difference is formed on the one panel wall, and the rib is formed at the position of the step. The blow molded article according to claim 4 , wherein the blow molded article is provided. In a blow molded body of a double wall panel structure having a substantially quadrangular shape in a plan view and comprising a side wall surrounding the front and back panel walls and four sides, a reinforcement for connecting one panel wall and the other panel wall in the vicinity of four corners. ribs are formed, the rib extends substantially perpendicularly toward the panel wall which faces continuously from both the panel wall consists of a top wall of the both side surfaces and the tip that is continuous with each panel wall, the two side surface portions Is a double-walled rib that is continuous at both ends in plan view , with both top surfaces facing each other and in close proximity at the middle position of both panel walls. A blow molded article characterized by being made. The blow molded body according to any one of claims 1 to 6 , wherein the rib is formed along a plane substantially perpendicular to a diagonal line connecting opposing corners. The blow molded body according to any one of claims 1 to 7 , wherein the parting line is set at a location closer to the one panel wall than the center of the side peripheral wall.

Images