JP2008273563A - Transport container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bottom plate of a carrying container made of a synthetic resin, which has a sufficient strength to prevent the bottom plate from deforming even though a heavy object is stored in the carrying container without increasing the weight of the container. <P>SOLUTION: The upper surface 2a of the bottom plate 2 is formed at a flat state, the lower surface 2b of a center section of the bottom plate 2 is formed along an arc a1 where the center A1 is located above the center section of the bottom plate 2, and the lower surface 2b of a peripheral section of the bottom plate 2 is formed along an arc b2 where the center B1 is located below the peripheral section of the bottom plate 2. Consequently, the center section of the bottom plate 2 becomes a thick wall and the peripheral section of the bottom plate 2 becomes a thin wall, so that toughness of the bottom plate 2 can be enhanced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transport container that is molded into a rectangular box by injection molding using a synthetic resin as a material.

  This type of transport container is used as a returnable box for transporting parts or a container for delivering goods in the logistics process, when storing and transporting heavy items or stacking and storing them in multiple stages. In addition, the container bottom plate to which a large load is applied is likely to be deformed. Therefore, as shown in FIG. 5, ribs are provided in a lattice shape on the lower surface of the bottom plate to increase the rigidity and prevent the deformation of the bottom plate (see, for example, Patent Documents 1 and 2).

Japanese Utility Model Publication No. 62-150323 JP 2000-226021

  In a container with ribs on the bottom surface of the bottom plate, the strength of the bottom plate can be increased by increasing the number of ribs installed or by increasing the thickness of the ribs to a thickness of about 4 mm, which is the limit of sink marks. The strength can be increased by increasing the thickness of the bottom plate itself without providing ribs.

However, increasing the number of ribs installed on the bottom surface of the bottom plate, increasing the thickness of the ribs, or increasing the thickness of the bottom plate increases the weight of the container. There is a problem that it is inconvenient to handle when the is empty.
Even if the container for transporting goods is transported to a destination such as a handrail, a conveyor, or a vehicle until it reaches the destination, it must be loaded and unloaded by the operator when the container is loaded on the destination or when the container is lowered at the destination. Is indispensable, and if the weight of the container to be loaded / unloaded is heavy, the burden on the worker will be increased. In order to reduce the transportation work, it is desired to use a lightweight container. However, there is no conventional container having a strong bottom plate and a light weight.

  In view of the above-mentioned problems of the prior art, the present invention does not cause deformation of the bottom plate of a transporting container used for a returnable box even if a heavy object is accommodated without increasing the weight of the container. It is an object to configure to a certain degree of strength.

  In order to solve the above problems, the present invention provides a transport container made of synthetic resin in which reinforcing ribs are integrally provided on the bottom surface of the bottom plate, and the bottom plate has a large thickness at the center and a small thickness at the periphery. The bottom surface of the center of the bottom plate is placed along an arc centered above the center of the bottom plate, the bottom surface of the periphery of the bottom plate is placed along an arc centered below the periphery of the bottom plate, and these arc surfaces are connected continuously. The bottom surface of the bottom plate is formed in the curved surface shape.

According to this, since the center part of the bottom plate where the load from the articles stored in the container is most concentrated is thickened to increase the rigidity, the heavy object placed on the bottom plate when the heavy object is stored in the container Even if a large downward load is applied, the bottom plate is not easily deformed, and the original shape can be maintained without being bent or warped. Further, since the peripheral portion of the bottom plate is thin, there is no increase in weight associated with varying the thickness of the bottom plate, and the weight of the container can be reduced.
In addition, by making the bottom surface of the thick portion at the center of the bottom plate and the bottom surface of the thin portion at the peripheral portion into a curved shape along a predetermined arc, the bottom plate has a flat top surface and a curved bottom surface. The thickness gradually changes continuously from the thick central portion to the thin peripheral portion. The toughness of the bottom plate is increased by providing the thickness of the bottom plate so as to continuously change.

  In the above configuration, if the ribs provided on the bottom surface of the bottom plate are provided so that the installation density per unit area is high in the central portion of the thick bottom plate and the installation density is low in the peripheral portion of the thin bottom plate, the ribs are stored. The rigidity of the center part of the bottom plate where the load of the article is concentrated can be further increased.

  The transport container of the present invention is applied to a container integrally molded by injection molding using a synthetic resin material such as polypropylene or polyethylene. In addition, when the container molded by injection molding has a large or small wall thickness on the container peripheral surface, deformation such as sinking or bending easily occurs due to a difference in cooling time. Therefore, the difference in thickness between the central part and the peripheral part of the bottom plate and the difference in thickness between the bottom plate and the other parts of the container are set within a range in which the container can be molded without causing deformation during injection molding. Is done.

A preferred embodiment of the present invention will be described with reference to the drawings.
1 is a perspective view of an upper surface side and a lower surface side of a transport container according to an embodiment of the present invention, FIG. 2 is a top view of the container of FIG. 1, and FIG. 3 is a longitudinal and short side along a cutting line in FIG. FIG. 4 is a cross-sectional end view in the short direction of the container according to another embodiment.

  As shown in FIGS. 1 and 2, the transport container 1 according to the present invention surrounds a bottom plate 2 having a rectangular shape in plan view with side plates 3, 3, 4, and 4, and a plurality of ribs 5 are provided on the lower surface of the bottom plate 2. It is formed in a bottomed box shape projecting downward and having an upper surface opened.

The side plates 3 and 3 are connected to the two short sides of the bottom plate 2, and the side plates 4 and 4 are connected to the two long sides and folded substantially at right angles to the bottom plate 2 to rise upward at an appropriate height. The flange 6 has an upper portion projecting outward.
The bottom plate 2 has a flat upper surface 2a on which the stored articles are placed, and ribs 5 that protrude downwardly from the lower surface with an appropriate length are arranged in a vertical and horizontal lattice pattern on the lower surface 2b. And while each said side plate and the flange 6 are formed with the substantially same thickness, the bottom plate 2 curves the lower surface 2b, makes the thickness continuously different, and thickens the center part of the bottom plate 2, The peripheral part is formed thinner than that.

More specifically, a cross section of the bottom plate 2 when the container 1 is cut along a line segment (AA) along the longitudinal direction passing through the center O of the bottom plate 2 shown in FIG. 2 is shown in FIG. As described above, the central portion of the lower surface 2b is along an arc of radius a1 centered on the point A1 on the vertical line passing through the center O, and both peripheral portions near the side plates 3 and 3 of the lower surface 2b are more than the bottom plate 2, respectively. It is formed along a circular arc of radius a2 with the center A2 below.
Further, a cross section of the bottom plate 2 when the container 1 is cut by a line segment (BB) along the short direction passing through the center O of the bottom plate 2 is a lower surface 2b of the bottom plate 2 as shown in FIG. Is centered along a circular arc having a radius b1 centered on a point B1 on the vertical line passing through the center O, and both peripheral portions near the side plates 4 and 4 of the lower surface 2b have the center B2 below the bottom plate 2, respectively. It is formed along the arc of the radius b2. In FIG. 3, illustration of the rib 5 integral with the lower surface 2b of the bottom plate 2 is omitted.
As shown in FIG. 3, the lower surface 2b is formed in a curved surface shape in which curved surfaces along the respective arcs are connected to each other, whereby the thickness between the upper and lower surfaces 2a, 2b of the bottom plate 2 is the center portion thereof. It is provided so as to be thickest at the center O of the film, and gradually become thinner from there to the periphery.

  In addition, the ribs 5 provided integrally with the lower surface 2b of the bottom plate 2 are not arranged at equal intervals throughout the lower surface 2b as shown in FIG. 5, but are shown in FIG. 1 (B). As shown, the installation density per unit area is high in the central area of the bottom plate 2 and lower in the peripheral area.

  As described above, the container 1 of the present embodiment has a thickened central portion of the bottom plate 2 where loads from articles stored in the container 1 are concentrated to increase the rigidity, and further, the lower surface 2b of the central portion of the bottom plate 2. The installation density of the ribs 5 provided in the above is increased. Therefore, even if a large downward load is applied from the article placed on the bottom plate 2, the bottom plate 2 is not easily deformed, and it is possible to maintain the original shape without bending or warping. Further, since the peripheral portion of the bottom plate 2 is thin and the interval between the ribs 5 is increased, the weight of the bottom plate 2 does not increase and the container 1 can be reduced in weight.

In the embodiment shown in FIG. 1, the bottom plate 2 is provided so that the thickness of the bottom plate 2 changes along both the long and short sides of the rectangular bottom plate 2 in a plan view. You may provide so that thickness may change along a direction. It is more preferable if the thickness is provided so as to change at least along the longitudinal direction.
The cross section of the bottom plate 2 when the thickness is changed only along the longitudinal direction of the bottom plate 2 having a rectangular shape in plan view is a line segment along the longitudinal direction passing through the center (A-A in FIG. 2). ), When the container 1 is cut, the shape is the same as that shown in FIG. On the other hand, when the container 1 is cut by a line segment (BB in FIG. 2) along the short direction passing through the center of the bottom plate 2, the shape shown in FIG. 4 (A) is obtained. When the container 1 is cut along a nearby line segment (C-C in FIG. 2), the shape shown in FIG. 4B is obtained. In FIG. 3, the rib 5 is not shown.

  In addition, the form of the illustrated container 1 is an example, and the present invention is not limited to the illustrated form, and can be configured in other appropriate forms, and the present invention can also be applied to a foldable container. The size of the container 1 and the thickness of each part including the bottom plate 2, the dimensions of the thick and thin portions of the bottom plate 2, the rate of gradually changing the thickness from the center to the periphery of the bottom plate 2, the number of ribs 5 installed The molding specifications of the container 1 such as the arrangement thereof can be appropriately set in consideration of the usage form of the container 1 such as the size and type of articles to be stored and the weight thereof.

It is the upper surface side perspective view (A) and lower surface side perspective view (B) of the container for conveyance of one Embodiment of this invention. It is a top view of the container of FIG. FIG. 3 is a longitudinal center cut end view (A) along the AA cut line in FIG. 2 and a short cut center end view (B) along the BB cut line in FIG. The center cutting end view (A) of both short directions along the BB cutting line of Drawing 2 in the container for transportation of other embodiments, and the cutting end view of the short direction along the CC cutting line of the figure (B). It is a lower surface side perspective view of the conventional container for conveyance.

Explanation of symbols

1 Transport container, 2 bottom plate, 2a top surface, 2b bottom surface, 3 (short side) side plate, 4 (long side) side plate, 5 rib, 6 flange

Claims (2)

In a synthetic resin transport container in which reinforcing ribs are integrally provided on the bottom surface of the bottom plate,
The thickness of the bottom plate is large at the center and small at the periphery, and the bottom surface of the bottom plate is along an arc centered above the center of the bottom plate, and the bottom surface of the bottom plate is the bottom plate periphery. A container for transportation characterized by being formed along an arc centered at the bottom. The transport container according to claim 1, wherein the density of ribs is set high at the center of the bottom plate and low at the periphery of the bottom plate.

Images