JP2013071749A - Synthetic resin folding structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin folding structure in which curving along a folding line is prevented when a V-shaped groove is formed on a synthetic resin sheet with a thermal creasing line and then the sheet is folded at a right angle and fixed.SOLUTION: The folding structure is formed of a laminated plate obtained by stacking and bonding three or more synthetic resin sheets. In one or more intermediate synthetic resin sheets except the synthetic resin sheets forming the top and bottom faces of the laminated plate, core member fitting portions formed of a hole or a recessed part extending along the predetermined folding line, are provided in regions having a reduced width from a predetermined folding line across the predetermined folding line formed in the laminated plate. A core member made from a rigid body is fitted to the core member fitting portion substantially with no gap therebetween.

Description

  The present invention relates to an improvement in a synthetic resin bent structure in which a V-shaped groove is formed by a heat ruled line in a synthetic resin sheet, and is bent and fixed at a right angle by hot bending.

Conventionally, for example, wooden trays and tables used for transporting stretched sheets as disclosed in JP-A-53-88381, for example, have a structure in which plywoods are connected by angle-shaped metal fittings. Although it is cheap, the life of timber is short, warping on the flat surface, wood chips stick to food, and the trays are placed in a steamer, so mold is easily generated and there are problems with hygiene. It was.
Further, for example, the scaffolding plate disclosed in Japanese Patent Application Laid-Open No. 11-193627 is made of wood or metal and has a problem that it is heavy and heavy to carry.
Therefore, it is conceivable to use a synthetic resin plate as a raw material. In particular, when forming a tray or a scaffolding plate using a synthetic resin hollow sheet, the sheet is laminated as a single layer or appropriately laminated, and a V-shaped thermal ruled line. However, there is a problem that the short-side piece is warped along the folding lines L1 and L2 due to shrinkage after melting by the thermal ruled line (see FIG. 7). ).
Therefore, conventionally, the warping has been corrected by applying heat and mechanical load by post-processing. However, even after-processing, it may return to its original state due to temperature rise during use.
This is a problem common to a bent structure in which a synthetic resin sheet is bent by forming a V-groove fold line with a heat ruled line, and a solution has been desired.

JP 53-88381

  The problem to be solved by the present invention is that a core material made of a plate-like rigid body such as a metal plate is used when a heat-bending process is performed by forming a V-groove fold line with a thermal ruled line on a synthetic resin sheet. An object of the present invention is to provide a bent structure that is built-in to suppress the occurrence of warping and at the same time has increased strength.

This invention was invented in view of the above circumstances,
In the invention of claim 1,
In a synthetic resin folded structure formed by forming a V-groove folding line with a thermal ruled line on a synthetic resin sheet and subjecting one piece sandwiching the folding line to heat bending at a substantially right angle to the other piece ,
The synthetic resin sheet is composed of a laminated plate in which three or more synthetic resin sheets are laminated and bonded,
One or a plurality of intermediate synthetic resin sheets excluding the front and back surfaces of the laminate, and folded into an area having a short distance from the assumed fold line across the assumed fold line formed on the laminate Provide a core material fitting part consisting of a hole or recess extending along the assumed line,
A core material made of a plate-like rigid body is fitted to the core material fitting portion with substantially no gap.
In the invention of claim 2,
A core material fitting portion for forming a core material made of a plate-like rigid body is formed in a pair of regions on the left and right outer sides with respect to a pair of assumed folding lines provided on the left and right sides of the laminated plate. It is characterized by being.
In the invention of claim 3,
The synthetic resin sheet is made of a synthetic resin hollow body sheet,
The opening of the edge part of a laminated board is closed and sealed by heat processing, It is characterized by the above-mentioned.
In the invention of claim 4,
In the intermediate synthetic resin sheet, an auxiliary core material fitting that extends in a direction orthogonal to the pair of bending assumption lines in a region inside the pair of left and right bending assumption lines provided on both sides of the laminated board. A joint portion is provided, and the auxiliary core material made of a plate-like rigid body is fitted to the auxiliary core material fitting portion without any substantial gap.
In the invention of claim 5,
The folded structure according to claim 1 is a folded body having a U-shaped cross section,
A leg foot portion having a larger installation area than the lower end of the side wall portion is externally fitted to the lower end of the left and right side wall portions of the bent body.
In the invention of claim 6,
5. The bent structure according to claim 1 is a U-shaped bent body, and a V-shaped bent curve is formed by heat ruled lines at the lower portions of the left and right side walls of the bent body. Then, it is bent at a substantially right angle with respect to the side wall portion, and the bent portion serves as a leg foot portion.

In the invention of claim 1, a core material fitting portion extending along an assumed bending line is provided in a synthetic resin sheet in the middle of a laminated board in which three or more synthetic resin sheets are laminated and bonded, and a metal plate or the like is provided there. By fitting a core material made of a plate-like rigid body, even if a V-groove fold curve is formed by a heat ruled line, warping of the bent piece is prevented, making correction work unnecessary, and folding at the same time. The strength of the piece can be increased. Further, no warp occurs due to temperature rise during use.
In the invention of claim 2, the intermediate synthetic resin sheet is formed of a plate-like rigid body by providing a core material fitting portion in a region on the left and right outer sides of a pair of assumed folding lines formed on both sides of the laminate. By fitting the core material, it is possible to make a synthetic resin bent structure that has a U-shaped cross section and does not cause warping of the bent piece.
In the invention of claim 3, by using a synthetic resin hollow body sheet for the synthetic resin sheet, the strength can be increased while being lightweight, and the end face of the folded piece of the laminate is sealed by thermal processing. Water resistance and dust resistance can be provided.
In the invention of claim 4, the intermediate synthetic resin sheet is provided with the auxiliary core material fitting portion in the central region surrounded by the pair of bending assumption lines, and the auxiliary core material of the plate-like rigid body is fitted. In addition, the strength of the portion that becomes the loading platform at the center of the laminated plate can be increased together.
In invention of Claim 5 or Claim 6, the leg | foot part of a separate body or an integral body can be formed, the area of the installation surface of a bending structure can be enlarged, and the stability at the time of installation can be aimed at.
Thus, when used for applications such as trays for stretching and scaffolding boards for construction, the number of laminated synthetic resin sheets of three or more can be appropriately increased according to the strength required for the application. In addition, the core material made of a rigid body can be reinforced by inserting the core material into a plurality of layers as well as one layer as long as it is an intermediate layer of a laminated sheet of synthetic resin sheets. The required strength can be provided.
In addition, since no warping occurs, the flatness can be maintained, and it is stable as a placement or scaffolding for stretching, and at the same time, peeling such as stretching is easy. Stable when stacked.
Furthermore, since a synthetic resin sheet is used, it is light and inexpensive, does not generate wood chips or metal powder, can be washed in a circle, has good drainage, and does not rust.

It is a perspective view of the bending structure of Example 1. It is a disassembled perspective view of a bending structure. It is a side view which shows the heat bending process by a heat ruled line in steps, (a) is a laminated body, (b) shows formation of a heat ruled line, (c) shows bending. It is a top view which shows the top-plate part of a bending structure. It is a bending structure of Example 2 which bent the side wall part of the bending structure into the leg foot part. (A) is a cross-sectional view of the bent structure when the core material is plate-like, (b) is a cross-sectional view of the bent structure body through which the core material fitting portion penetrates a plurality of intermediate layers, (c) It is sectional drawing of the bending structure in which the core material fitting part was intermittently provided in the some intermediate | middle layer, and was provided with two or more. It is a perspective view of the conventional bending structure.

A core material fitting portion is formed on a synthetic resin sheet in the middle of a laminated body in which three or more synthetic resin sheets are stacked along an assumed bending line by a heat ruled line, and the core material made of a plate-like rigid body is used as the core material. By fitting in the fitting part, the occurrence of warpage along the folding line due to the thermal ruled line was suppressed, and at the same time the strength was improved.
Hereinafter, embodiments in which the synthetic resin bent structure of the present invention is applied to a tray having a U-shaped cross section will be described with reference to the drawings.

The tray T shown in FIG. 1 includes a folded structure 1 having a U-shaped cross section serving as a tray main body, and a pair of leg feet 10 fitted to the lower end of the folded structure 1.
As shown in FIG. 3A, the bent structure 1 is formed by using a V-shaped heat bar V on a laminated plate 5 in which three or more (three in the illustrated example) synthetic resin hollow body sheets are stacked and bonded. From the structure (see FIG. 3 (c)) that is pressed and melted to form a pair of left and right bent grooves L1 and L2 (see FIG. 3 (b)) and then bent and welded at a substantially right angle after this melting. It has become.

  In this example, the synthetic resin corrugated cardboard is used as the synthetic resin hollow body sheet, which is discharged and molded as a single unit by one extrusion. Further, synthetic resin sheets that can be subjected to heat bending, such as other hollow synthetic resin sheets, can be used.

As shown in FIG. 2, the laminated plate 5 includes a first synthetic resin hollow body sheet 2 serving as a surface layer, a second synthetic resin hollow body sheet 3 serving as an intermediate layer, and a back surface (inner surface) layer. 3 It is comprised by bonding together the synthetic resin hollow body sheet 4.
And in the second synthetic resin hollow body sheet 3 of the intermediate layer that is not exposed on the front surface and the back surface, the bending assumption lines L1 ′, L2 ′ sandwiched between the bending assumption lines L1 ′, L2 ′ formed on the laminated plate 5, In the region 3A of the side wall forming portion having a short distance from L2 ′, the core material fitting portion 6 including a hole or a recess extending along the assumed folding lines L1 ′ and L2 ′ is provided.

In the present embodiment, the core material fitting portion 6 is formed of a rectangular through-hole, and the core material 7 is formed on the core material fitting portion 6 so that the outer peripheral surface thereof is substantially the same as the inner peripheral surface of the core material fitting portion 6. It is fitted so that there is no gap.
The core material 7 is made of a metal plate such as an aluminum plate or other plate-like rigid body, and the entire core material 7 has only to be large enough to be accommodated in the core material fitting portion 6 without any gap. In order to enhance, it is formed in a channel shape in cross section, but it may be a simple flat plate shape or any other shape such as a plate having an angle cross section in which only one is bent.

  The lengths of the core material fitting portion 6 and the core material 7 are preferably formed to be long corresponding to the bending assumption lines L1 ′ and L2 ′, but the thickness and dimensions of the laminated plate 5, the strength of the core material 7, and the like It is sufficient that the length is set so as not to cause warpage, and at least half the length of the assumed bending lines L1 ′ and L2 ′ is preferable, and the center of the assumed bending lines L1 ′ and L2 ′ is fitted to the core material. It is preferable to align the part 6 and the center of the core material 7.

  The first synthetic resin hollow body sheet 2 is integrally bonded with an adhesive tape or adhesive on the second synthetic resin hollow body sheet 3 in which the core material 7 is fitted in the core material fitting portion 6. The upper surface of the joint portion 6 is closed, and the third synthetic resin hollow body sheet 4 is integrally bonded with an adhesive tape or an adhesive under the second synthetic resin hollow body sheet 3 to close the lower surface of the core material fitting portion 6. Then, the three layers of the synthetic resin hollow body sheets 2, 3, 4 are bonded together to form the laminated plate 5.

  The laminated plate 5 incorporating the core material 7 formed in this way is subjected to a thermal bending process consisting of thermal ruled lines as shown in FIG. 3, and the left and right sides are bent at a right angle to form a pair of left and right side walls. 1A and the top plate portion 1B supported by the side wall portion 1A are formed into a U-shaped cross section.

The first synthetic resin hollow body sheet 2 and the third synthetic resin hollow body sheet 4 of the laminated plate folded as described above are synthetic resin hollow body sheets in a direction intersecting with the folding lines L1 and L2. From the viewpoint of strength, it is preferable to form the flow line, and therefore, an opening communicating with the hollow portion is exposed at the lower end portion of the side wall portion 1A of the bent structure 1. On the other hand, the flow of the second synthetic resin hollow body sheet 3 is preferably orthogonal to the flow of the first and third synthetic resin hollow body sheets 2 and 4.
In the present invention, it may be used as a tray with the above-described configuration. However, in this embodiment, the end portion is closed by heat processing and sealed in a circular arc shape to prevent intrusion of liquid such as water and dust. Thereby, washing with water becomes possible, and it is preferable in terms of hygiene as a tray on which food is placed. Furthermore, the integration of the three-layer synthetic resin hollow body sheets 2, 3, 4 is strengthened by thermal processing.

Since the lower end of the side wall portion 1A of the bent structure 1 is a curved surface R, a separate leg foot portion 10 may be fitted to widen the contact surface with the installation surface.
The leg foot portion 10 has a fitting groove portion 11 that fits the lower end of the side wall portion 1A, and extends the bottom wall of the fitting groove portion 11 to one or both in order to widen the contact area with the installation surface. You may provide the extension part 12 to be made.
The leg foot portion 10 may be fitted with the lower end of the side wall portion 1A and has a wider installation surface than the lower end of the side wall portion 1A. In the present invention, the leg foot portion 10 may or may not be provided. .

In the above embodiment, the structure in which the core material 7 is built only in the side wall portion of the bent structure 1 is shown, but the auxiliary core material 9 may be built in the top plate portion.
The auxiliary core material 9 is also made of a plate-like rigid body, but may be the same as or different from the core material 7.
In Example 2, the laminated plate 5 has a three-layer structure as in Example 1, and the second synthetic resin hollow body sheet 3 serving as an intermediate layer is bent as shown in FIG. Auxiliary core material fitting consisting of a hole or a recess extending in a direction orthogonal to the assumed bending lines L1 'and L2' is placed in the wide top plate forming region 3B sandwiched between the assumed lines L1 'and L2'. A plurality of portions 8 are provided at substantially equal intervals, and the auxiliary core material 9 of a plate-like rigid body is fitted to the auxiliary core material fitting portion 8 with substantially no gap.

In the illustrated example, since the folded structure 1 has a three-layer structure, the core material fitting portion 6 and the auxiliary core material fitting portion 8 are formed in the second synthetic resin hollow body sheet 3 which is the only intermediate layer. However, in the case of four or more layers, the intermediate layer is composed of a plurality of synthetic resin hollow body sheets, so that the intermediate layer synthetic resin is different from the core material fitting portion 6 and the auxiliary core material fitting portion 8. You may form in a hollow body sheet.
Since other configurations are the same as those of the first embodiment, the description thereof is omitted.
In this case, the warp of the side wall portion can be suppressed, and the strength of the top plate portion can be increased together with the side wall portion.

The tray T according to the third embodiment folds the side wall portion 1A which is vertically erected by heat-bending the lower portion of the side wall portion 1A of the bent structure 1 with a heat ruled line without separating the leg and foot portions. A different configuration is shown in which the bent portions are bent inward at right angles (horizontal) along the curves L3 and L4, and the bent portions are used as the leg feet 10 ′.
In this case, the laminated plate 5 can be formed into a tray T having a top plate portion 1B supported by a pair of side wall portions 1A with leg feet 10 ′ only by hot bending with a heat ruled line.

FIG. 6 shows another embodiment.
FIG. 6A illustrates the case where the core material 7 has a plate shape instead of a U-shaped cross section, but may be a hollow pipe shape, a corrugated shape, a continuous uneven shape, or other folded plate structure. As described above, any cross-sectional shape can be used.
In FIG. 6B, the intermediate layer 3 is composed of a plurality of layers (two layers in the illustrated example), and the core material fitting portion 6 is composed of a hole that is integrally formed through the plurality of intermediate layers 3. The core material fitting portion 6 is fitted with one core material 7.
FIG. 6C illustrates a case where the intermediate layer 3 is composed of three or more layers, and the core material fitting portion 6 is provided not intermittently between the plurality of intermediate layers 3, but provided intermittently. The core material 7 is fitted to the core material fitting portion 6.
Moreover, the core material fitted to one core material fitting part may be formed integrally by combining a plurality of members.

In the above embodiment, the tray including the top plate portion and the pair of side wall portions has been described as the folding structure. However, in the present invention, the folding structure is formed by performing at least one thermal bending process using a thermal ruled line. If it exists, it may be an angle-shaped article or an article having an arbitrary shape having three or more folding lines.
In addition, it goes without saying that various design changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Folding structure 1A Side wall part 1B Top plate part 2 The 1st synthetic resin hollow body sheet (surface layer)
3 Second synthetic resin hollow sheet (intermediate layer)
3A Region of side wall forming portion 3B Region of top plate forming portion 4 Third synthetic resin hollow body sheet (back surface (inner surface) layer)
DESCRIPTION OF SYMBOLS 5 Laminated board 6 Core material fitting part 7 Core material 8 Auxiliary core material fitting part 9 Auxiliary core material 10, 10 'Leg foot part 11 Fitting groove part 12 Extension part V V-shaped heat bar L1, L2 Folding curve ( (For side wall formation)
L1 ', L2' bending assumption lines L3, L4 bending curves (for leg and foot formation)

Claims (6)

A synthetic resin fold formed by forming a V-groove fold with a heat ruled line on a synthetic resin sheet, bending one piece sandwiching the fold to the other piece at a substantially right angle, and welding together. In the structure,
The synthetic resin sheet is composed of a laminated plate in which three or more synthetic resin sheets are laminated and bonded,
One or a plurality of intermediate synthetic resin sheets excluding the front and back surfaces of the laminate, and a hole extending along the assumed bending line in one region facing the expected bending line formed on the laminated plate Or provide a core material fitting part consisting of a recess,
A bent structure comprising: a core made of a rigid body integrally formed with the core material fitting portion and fitted with substantially no gap.   A core material fitting portion for fitting a core material made of a rigid body is formed in a pair of regions on the left and right sides with respect to a pair of assumed bending lines provided on the left and right sides of the laminate. The bent structure according to claim 1. The synthetic resin sheet is a hollow sheet,
The folded structure according to claim 1 or 2, wherein an opening at an end of the laminated plate is sealed by thermal processing and sealed.   Auxiliary core material fitting that extends in a direction perpendicular to the pair of bending assumption lines in a region that is inside the pair of left and right bending assumption lines provided on both sides of the laminated board with an intermediate synthetic resin sheet The bent structure according to any one of claims 1 to 3, characterized in that a rigid auxiliary core member is fitted to the auxiliary core member fitting portion without any gap. The folded structure according to claim 1 is a folded body having a U-shaped cross section,
A bent structure, wherein a leg foot portion having a larger installation area than the lower end of the side wall portion is externally fitted to the lower end of the left and right side wall portions of the bent body. The folded structure according to claim 1 is a folded body having a U-shaped cross section,
A lower part of the left and right side wall portions of the bent body is formed with a V-groove-shaped fold curve with heat ruled lines and bent at a substantially right angle with respect to the side wall portion, and the bent portion serves as a leg foot portion. A bent structure.

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