JP2010001066A - Plastic sheet-made box body, its production method, production device and corner member for stacking plastic sheet-made box body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sturdy plastic sheet-made box body, its production method and a production device for producing the box body inexpensively with a fewer parts not requiring a separate member such as a frame member for reinforcing the open top end of the box body made of a plastic corrugated board box etc. <P>SOLUTION: The plastic sheet-made box body 1 is formed in a box shape with an open top end face using a plastic sheet. The top end edge of at least two facing sidewalls 9, 10 of the sidewalls 9, 10, 11, positioned on the outside periphery of the plastic box body is turned back outward to structure the edge double layered. The inside face of turned back parts 9b, 10b are mutually fused. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plastic sheet box formed in a box shape using a plastic sheet-like member (hereinafter referred to as “plastic sheet”) such as a plastic cardboard made of a thermoplastic resin, and a method for manufacturing the same. The present invention relates to a manufacturing apparatus and a corner member for volume stacking of plastic sheet boxes.

JP-A-10-109368 JP 2001-354228 A

  Conventionally, plastic cardboard boxes manufactured using this type of plastic cardboard are superior to paper cardboard boxes because they are not easily soiled by dust or dust, are clean, and have water resistance. It is widely used for storing and transporting industrial products, foodstuffs, and daily necessities. The plastic cardboard box is lighter than a plastic case or the like, and is characterized in that it can be easily transported. Furthermore, the plastic cardboard box is made of a plurality of plastic cardboard boxes in order to efficiently store and transport the plastic cardboard box, such as when storing and transporting articles such as industrial products, foodstuffs, and daily necessities. It is often stored and transported with cardboard boxes stacked one above the other.

  By the way, the plastic cardboard box is formed by cutting a plastic cardboard made of thermoplastic resin into a predetermined shape and bending it into a box shape. Manufactured by joining.

  At that time, as a joining technique for joining the joining margins of the plastic cardboard, for example, as disclosed in JP-A-2001-354228, ultrasonic waves are applied to the plastic cardboard to generate frictional heat. And a technique for melting and joining plastic corrugated cardboard made of a synthetic resin having thermoplasticity, as disclosed in JP-A-10-109368, have already been proposed. .

  The plastic corrugated cardboard box according to the above Japanese Patent Application Laid-Open No. 2001-354228 is an assembly box made of a die-cut plastic corrugated sheet, and all the constituent members of the box are made of the same polyolefin-based material. The bonding between the materials is performed by welding, and ultrasonic waves are used as welding means.

  In addition, the plastic corrugated board bonding method according to the above-mentioned Japanese Patent Application Laid-Open No. 10-109368 is substantially the same thickness as the hot plate so that the hot plate for heating the bonded surface is not pressed beyond contacting the bonded surface. The spacing plate is provided in the vicinity of the heating plate in the same plane as the heating plate, the heating plate and the spacing plate are sandwiched between the joining surfaces, and the joining surface is melted by the heat of the heating plate. Then, the bonding surfaces are brought into close contact with each other, and the cardboards are bonded to each other by heat welding.

  However, the conventional technique has the following problems. That is, in the case of the plastic corrugated cardboard box according to the above-mentioned Japanese Patent Application Laid-Open No. 2001-354228, in order to fit the frame member to reinforce the upper end of the opening or to stack the plastic cardboard boxes up and down In addition, it is necessary to fix the corner member, and the number of parts constituting the plastic cardboard box is increased, so that the manufacturing process is complicated, and the manufacturing cost is increased.

  In the case of the plastic corrugated cardboard box according to the above-mentioned Japanese Patent Application Laid-Open No. 2001-354228, ultrasonic waves are used as welding means for welding the plastic corrugated cardboard sheets. Welding, the vicinity of the welded portion of the plastic corrugated cardboard sheet that is welded by ultrasonic waves is whitened by rubbing due to ultrasonic vibration, so-called “whitening”, and the appearance is deteriorated. It was.

  Further, in the case of the plastic corrugated board bonding method according to the above-mentioned JP-A-10-109368, a hot plate and a spacing plate are sandwiched between the plastic cardboard joint surfaces, and the joint surface is melted by the heat of the hot plate. After that, the heat plate and the spacing plate are removed, and then the joining surfaces are brought into close contact with each other, and the corrugated cardboards are joined together by heat welding. However, when the plastic corrugated cardboard is melted with heat, the plastic corrugated board is heated over a relatively large area. There has been a problem that the appearance of the plastic cardboard box is deteriorated. In addition, when storing industrial products that require high precision in plastic cardboard boxes manufactured by the plastic cardboard bonding method, it is possible to store industrial products with high accuracy by deformation of the plastic cardboard. It also had the problem that it was not possible.

  Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and its object is to reinforce the open upper end of a plastic sheet box such as a plastic cardboard box. Another object is to provide a plastic sheet box, a method for manufacturing the same, and a manufacturing apparatus that do not require a separate member such as a frame member, can be manufactured at a low cost with a small number of parts, and have sufficient strength. is there.

  Another object of the present invention is that when plastic sheets such as plastic corrugated cardboard are welded together, the plastic sheets cause so-called “whitening” and the appearance is deteriorated, or the plastic sheets are deformed by heat. It is an object of the present invention to provide a plastic sheet box, a manufacturing method thereof, and a manufacturing apparatus.

  Furthermore, another object of the present invention is to provide a corner member for stacking plastic sheet boxes suitable for use when stacking the plastic sheet boxes described above.

That is, the invention described in claim 1 is a plastic sheet box formed in a box shape having an upper end surface opened by a plastic sheet.
Among the side walls located on the outer periphery of the plastic sheet box, at least the upper end edges of two opposing side walls are folded outward to form a double, and the inner surfaces of the folded parts are welded together This is a plastic sheet box.

  Further, in the invention described in claim 2, the plastic sheet box is composed of a bottom wall and four side walls erected around the bottom wall, and the adjacent side walls are connected to each other by the adjacent side walls. 2. The plastic sheet box according to claim 1, wherein the plastic sheet box is formed in a box shape having an open upper end surface by spot welding to each other through a joining margin provided on one side.

  Further, in the invention described in claim 3, the plastic sheet box is composed of a bottom wall and four side walls standing around the bottom wall, and the adjacent side walls are connected to each other. 2. The structure according to claim 1, which is configured to be disassembled and assembled into a box shape with an upper end surface opened by joining by means of detachable joining means via a joining margin provided on one side. A plastic sheet box.

  According to a fourth aspect of the present invention, a corner member for stacking the plastic sheet boxes is fixed to a corner of the upper end surface of the plastic sheet box. A plastic sheet box according to any one of claims 1 to 3.

Furthermore, the invention described in claim 5 is a method for manufacturing a plastic sheet box formed in a box shape having an upper end surface opened by a plastic sheet.
A cutting step of cutting one or more plastic sheet pieces of a predetermined shape formed in a box shape with an upper end surface opened by joining the plastic sheets in a folded state;
When one or more plastic sheet pieces cut by the cutting step are joined in a folded state, a plastic sheet box having an open upper end surface is formed on the outer periphery of the plastic sheet box. Two grooves having a V-shaped cross section for melting in parallel along the upper edge are melted on the outer surface of the plastic sheet piece corresponding to the upper edges of at least two opposing side walls among the side walls positioned. And a melting step of melting the outer surfaces adjacent to both sides of the two groove portions,
By folding the outer surface of the plastic sheet piece corresponding to the upper edge of at least two opposing side walls outward at the position of the two grooves melted by the melting step, the at least two opposing side walls And a fixing step for fixing the melted inner surfaces of the folded-back portions to each other, and a method for manufacturing a plastic sheet box.

Further, the invention described in claim 6 is an apparatus for manufacturing a plastic sheet box formed in a box shape having an upper end surface opened by a plastic sheet.
When forming a plastic sheet box having an upper end opened by joining the plastic sheets in a folded state, at least two side walls facing each other among the side walls located on the outer periphery of the plastic sheet box Two convex portions formed by melting two groove portions having a V-shaped cross section for folding back in parallel along the upper end edge on the outer surface of the plastic sheet piece corresponding to the upper end edge, and the 2 A heating contact having a flat plate portion adjacent to both sides of the convex portion of the book;
An apparatus for manufacturing a plastic sheet box, comprising: a moving means for moving the heating contact element in a direction to be in contact with or separated from the surface of the plastic sheet.

  Furthermore, when the invention described in claim 7 is formed by melting two groove portions having a V-shaped cross section on the outer surface of the plastic sheet by the two convex portions of the heating contactor, 7. The plastic sheet box manufacturing apparatus according to claim 6, wherein a thin sheet having releasability is interposed between the convex portion of the heating contact and the plastic sheet.

The invention described in claim 8 is a plastic sheet box formed in a box shape having an upper end surface opened by a plastic sheet, and at least two of the side walls located on the outer periphery thereof are opposed to each other. In the corner member for plastic sheet box volume stacking used for stacking up and down the plastic sheet box body that is doubled by folding the upper edge of one side wall outward,
A fixing portion to be mounted in a state of being fixed to a corner portion of the opened upper end surface of the plastic sheet box,
A regulation plate having two regulation plates that are provided integrally with the fixed portion and are in contact with two adjacent side walls of a corner located at the lower end of the plastic sheet box stacked on top;
Of the two restricting plates of the restricting plate portion, the restricting plate that contacts the lower end of the side wall where the upper end edge of the plastic sheet box is folded outward is more than the restricting plate that contacts the other side surface. It is a corner member for volume stacking of plastic sheet boxes, which is provided by being displaced inside a plastic sheet box body.

  Furthermore, the invention described in claim 9 is such that the corner member for stacking the plastic sheet box is freely expandable to a member attached to each of two adjacent side walls located at the corner of the plastic sheet box. The corner member for plastic sheet box volume stacking according to claim 8, wherein the corner member is configured as described above.

  According to this invention, in order to reinforce the open upper end portion of the plastic sheet box such as a plastic cardboard box, a separate member such as a frame member is unnecessary, and the number of components is small and the manufacturing cost is low. In addition, a plastic sheet box having a sufficient strength, a manufacturing method thereof, and a manufacturing apparatus can be provided.

  In addition, according to the present invention, when plastic sheets such as plastic cardboard are welded together, the plastic sheet does not cause a so-called “whitening” to deteriorate its appearance, or the plastic sheet is not deformed by heat. A box body, a manufacturing method thereof, and a manufacturing apparatus can be provided.

  Furthermore, according to the present invention, it is possible to provide a plastic sheet box volume stacking corner member suitable for use in stacking the above-described plastic sheet box bodies.

  Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1
1 and 2 show a plastic cardboard box as a plastic sheet box manufactured by a manufacturing method and a manufacturing apparatus of a plastic sheet box according to Embodiment 1 of the present invention. In addition, in FIG. 1 etc., the part notched round is for showing the direction of the rib of a plastic sheet for convenience, and of course does not necessarily have a round opening.

  As shown in FIGS. 1 and 2, the plastic cardboard box 1 is formed by a plastic cardboard 2 as a plastic sheet in the shape of a rectangular parallelepiped box whose upper end surface 3 is fully open. In this case, storage or transportation is performed in a state in which desired products such as industrial products such as precision machine parts, foodstuffs, or daily necessities are stored. The plastic cardboard 2 used to manufacture the plastic cardboard box 1 is not particularly limited, and various plastic cardboards 2 can be used. For example, as the plastic corrugated cardboard 2, as shown in FIG. 3, a pair of front and back plastic flat plates 4, 5 are arranged in parallel at regular intervals along the surface so as to be orthogonal to the plastic flat plates 4, 5. What was mutually connected by many standing ribs 6 is used. The plastic cardboard 2 is manufactured by integrally molding a plastic (synthetic resin) having thermoplasticity such as polypropylene by an extrusion molding machine. The plastic corrugated cardboard 2 is not limited to this. As shown in FIG. 4, ribs 6 formed in a small cylindrical shape are arranged at regular intervals in the vertical and horizontal directions. As shown in FIG. 5, an arbitrary one such as one in which a pair of front and back plastic flat plates 4 and 5 are connected by a rib 6 swelled in a substantially semi-elliptical shape from the vertical direction may be used. Of course it is good.

  Further, the plastic sheet 2 is not limited to the plastic cardboard described above, and a plastic (synthetic resin) such as polypropylene or polyethylene is formed into a sheet having a predetermined thickness as shown in FIG. 5B. As shown in FIG. 5 (c), a dense surface foamed by mixing a foaming agent with plastic (synthetic resin) such as polypropylene, such as Sumicella (trade name, manufactured by Sumika Plastics). You may use the sheet | seat made from a polypropylene of the expansion ratio 2-6 times which consists of a layer and a micro closed-cell foam. At that time, the plastic sheet may be in a state where both the front and back surfaces are molded, but of course, a thin sheet made of the same plastic (synthetic resin) may be used on both the front and back surfaces of the plastic sheet. good.

  As shown in FIG. 6, the plastic corrugated cardboard box 1 is bonded at predetermined locations to each other with at least one plastic corrugated cardboard piece 7 cut into a predetermined developed shape folded in a box shape. Manufactured by. As the plastic cardboard piece 7 forming the plastic cardboard box 1, for example, the plastic cardboard box 1 formed in the shape of a rectangular parallelepiped box having the entire upper end surface 3 as shown in FIG. 2 is developed. A shape obtained by cutting a single plastic cardboard 2 is used.

  As shown in FIG. 6, the plastic cardboard piece 7 basically has a bottom wall 8 formed in a rectangular shape located at the bottom of the plastic cardboard box 1 and a state where the plastic cardboard piece is bent on the outer periphery of the bottom wall 8. It is comprised so that it may have four side walls 9, 10, 11, and 12 erected by 1 integrally. For example, the bottom wall 8 is formed in a rectangular shape in which one side 8a is longer than the other side 8b, but is not limited to this, and the square shape or one side 8a is shorter than the other side 8b. Of course, it may be formed in a rectangular shape or the like, and its shape is arbitrary. Further, the heights of the side walls 9, 10, 11, 12 are also appropriately set according to the depth of the plastic cardboard box 1.

  Further, of the four side walls, the pair of side walls 9 and 10 facing each other have corner portions when the joint allowances 13, 14, 15 and 16 for joining the adjacent side walls 11 and 12 are bent. It is extended in the both-sides edge located in each. When the plastic cardboard piece 7 is assembled into a box shape, the adjacent side walls 9, 10, 11, 12 are joined to each other through these joining margins 13, 14, 15, 16. The upper end surface 3 is assembled into a box shape with an opening. When cutting the plastic cardboard piece 7, for example, as shown in FIG. 6, the rib 6 of the plastic cardboard 2 constituting the plastic cardboard piece 7 is formed on the short side 8 b of the bottom wall 8. Although it cut | disconnects so that it may become parallel, it is not necessarily limited to this.

  Further, as shown in FIGS. 1 and 2, the plastic cardboard box 1 includes at least the upper ends of two side walls 9, 10 facing each other among the four side walls 9, 10, 11, 12 positioned on the outer periphery thereof. The edges 9a and 10a are folded outward to form a double structure, the inner surfaces of the folded portions 17 and 18 are welded together, and the upper end surfaces 9b and 10b of the side walls 9 and 10 are formed flat. And reinforced.

  Therefore, among the four side walls 9, 10, 11, 12 located on the outer periphery of the plastic cardboard box 1, As shown in FIG. 6, folding margins 19 and 20 for forming the folding portions 17 and 18 are extended. Note that the length L of the folding allowances 19 and 20 is set to an arbitrary length.

  Further, in this embodiment, as shown in FIG. 7, when the plastic cardboard box 1 is manufactured, two outer side surfaces of the upper end edges 9a and 10a corresponding to the folding positions of the two side walls 9 and 10 are provided. Concave grooves 21 and 22 having a V-shaped cross section (resulting in a W-shaped cross section) are provided in parallel along the upper end edges 9a and 10a, and the concave grooves 21 and 22 having a V-shaped cross section are provided. And bend outward. The concave grooves 21 and 22 having a V-shaped cross section are set to a distance of about 2 t when the thickness of the plastic corrugated cardboard 2 is t, and the angle θ is determined by a heating process described later. The value after forming the groove is approximately 90 degrees.

  Further, as shown in FIG. 8, the plastic cardboard box 1 is folded back to the outside and the inner surfaces of the folded portions 17 and 18 formed in a double manner have two concave grooves 21 having a V-shaped cross section. The upper end edges 9a and 10a of the plastic cardboard box 1 are reinforced and the end faces 9b and 10b are formed flat.

  Further, the plastic cardboard box 1 may be configured to be doubled by folding the upper end edges of the other two side walls 11 and 12 opposite to each other in the same manner. Since the side walls 11 and 12 are normally configured to be doubled by folding the joint margins 13, 14, 15 and 16, it is not necessary to fold back the upper edge of the side walls 11 and 12 to be doubled.

  However, the other two side walls 11 and 12 facing each other are usually doubled by folding back the joining margins 13, 14, 15 and 16, but the upper end surface of the plastic cardboard 2 is cut. The surface is exposed and is not formed flat, and there is a possibility that foreign matter may enter. Therefore, it is desirable that the other two side walls 11 and 12 facing each other are also formed in a double shape by folding the upper end edge outward.

  In this case, as the plastic cardboard piece 7 forming the other two side walls 11 and 12 facing each other, as shown in FIG. 6, one integrally formed with the bottom wall 8 may be used. However, as shown in FIG. 9, the plastic cardboard pieces 7 b and 7 c forming the two side walls 11 and 12 are made of plastic cardboard pieces configured as separate members from the plastic cardboard pieces 7 a forming the bottom wall 8. It is desirable to use it.

  The reason is that, as the plastic cardboard 2, for example, as shown in FIG. 3, a pair of front and back plastic flat plates 4 and 5 are fixed along the surface so as to be orthogonal to the plastic flat plates 4 and 5. The plastic cardboard 2 is connected to each other by a large number of ribs 6 standing in parallel at intervals. The plastic cardboard 2 has a large number of ribs 6 running in one direction with respect to the surface of the plastic cardboard 2. . Therefore, when the other two side walls 11 and 12 are formed in addition to the two side walls 9 and 10 by one plastic cardboard 2, the plastic cardboard 2 forming the two side walls 11 and 12 is As shown in FIG. 6, the arrangement direction of the large number of ribs 6 is positioned in a direction parallel to the upper end edges of the side walls 11 and 12.

  Therefore, when the plastic corrugated cardboard 2 forming the side walls 11 and 12 is folded outward, the two side walls 11 and 12 are positioned in parallel to the positions where the ribs 6 are folded. The case where it comes to the same position as the rib 6 and the case where it deviates from the rib 6 occur.

  Considering this point, even when the plastic corrugated cardboard 2 forming the two side walls 11 and 12 is folded outward, the rib 6 of the plastic corrugated cardboard 2 may be positioned in a direction perpendicular to the folding direction. Desirable in strength.

  In this case, the arrangement direction of the ribs 6 of the four side walls 9, 10, 11, 12 cannot be set to a direction orthogonal to the bending direction with one plastic cardboard 2. Therefore, as the plastic cardboard 2 constituting the other pair of side walls 11 and 12, it is desirable to use plastic cardboard pieces 7a, 7b and 7c as separate members, as shown in FIG. As a plastic cardboard piece 7 constituting one plastic cardboard box 1, a plastic cardboard piece 7a constituting the bottom wall 8 and one side walls 9, 10 and the other side walls 11, 12 are Three plastic cardboard pieces 7 a, 7 b, and 7 c, which are composed of a plastic cardboard piece 7 b constituting one side wall 11 and a plastic cardboard piece 7 c constituting the other side wall 12, are required. In this case, it is desirable to cut the plastic cardboard pieces 7b and 7c constituting the side walls 11 and 12 so that the ribs 6 of the plastic cardboard 2 are arranged along the height direction of the side walls 11 and 12. .

  When one plastic cardboard box 1 is composed of three plastic cardboard pieces 7a, 7b and 7c, the side walls 9 and 10 are connected to the side walls 9 and 10, respectively, in order to increase the strength of the plastic cardboard box 1. 13, 14, 15, and 16 are provided, and joining margins 23 and 24 are also provided on the bottom wall 8. Further, the joining margins 13, 14, 15, 16 and the joining margins 23, 24 are set to be narrow, and adjacent corners are respectively provided with notches 13a, 14a, 15a, 16a and 23a, 24a is provided. Further, folding margins 25 and 26 are extended along the upper end edges 11a and 12a of the side walls 11 and 12, respectively.

  In such a case, as shown in FIG. 9, the folding margins 25 and 26 of one side wall 11 and 12 and the joining margins 13, 14, 15, and 16 of the other side walls 9 and 10 do not interfere with each other. In addition, it is desirable to cut away both ends of the folding margins 25 and 26 of the other side walls 9 and 10 by a width corresponding to the joining margins 13, 14, 15 and 16. The notches 25a and 26a may be provided in the joining margins 13, 14, 15 and 16 of the side walls 9 and 10, but if the notches are provided in the joining margins 13, 14, 15 and 16 respectively. Since there is a concern that the bonding strength between the side walls 11 and 12 and the side walls 9 and 10 may be reduced, it is desirable to provide notches 25a and 26a in the folding margins 25 and 26 of the side walls 11 and 12.

  The plastic corrugated cardboard box 1 constructed as described above joins predetermined portions to each other in a state where one plastic corrugated cardboard piece 7 or three plastic corrugated cardboard pieces 7a, 7b, 7c are bent as will be described later. Manufactured by doing.

  FIG. 10 shows a first manufacturing apparatus for a plastic sheet box body to which a manufacturing method for manufacturing a plastic sheet box body configured as described above is applied. The first manufacturing apparatus for a plastic sheet box is an apparatus for forming a folded portion at a portion corresponding to the upper edge of the side wall of the plastic sheet piece.

  In FIG. 10, 100 shows the 1st manufacturing apparatus main body of a plastic sheet box, and this 1st manufacturing apparatus main body 100 is made into the column or prism shape which was made to stand by the leg part 101 on the floor surface. Is formed. In the upper intermediate portion of the first manufacturing apparatus main body 100, a work table 102 is extended in a flat plate shape having a predetermined width along one side surface along the horizontal direction. The work table 102 is relatively wide and long, and the upper surface of the work table 102 is horizontally formed. Further, a buffer material sheet 103 for fixing the back surface of the work piece is fixed to the upper surface of the work table 102 by means such as adhesion. Further, a positioning member 104 is provided on the upper surface of the workbench 102 as needed to abut the end of a plastic corrugated cardboard piece 7 as a work piece and position it at a predetermined position. Note that the cushioning sheet 103 is not necessarily provided.

  Further, at the upper end of the first manufacturing apparatus main body 100 of the plastic corrugated cardboard box, as shown in FIG. 10, a cylinder is formed on one side surface along the horizontal direction so as to be parallel to the work table 102 described above. A cylindrical working arm 105 having a rectangular shape or cross section is extended. At the tip of the working arm 105, a plastic cardboard piece as a work piece placed on the workbench 102 is heated and melted, so that two cross-sections are formed at predetermined positions of the plastic cardboard piece. A heating means 106 for simultaneously heating and melting the surface of the plastic cardboard piece adjacent to the two V-shaped groove sections is mounted while simultaneously forming the V-shaped groove sections. In addition, you may provide the clamp means which is not shown in figure in the front-end | tip part of the said working arm 105, and fixes in the state which pressed down the surface of the plastic cardboard piece.

  Further, in the first manufacturing apparatus 100 for a plastic cardboard box, as shown in FIG. 10, a work part mounting plate 107 formed in a rectangular shape is provided along the vertical direction at the tip of the work arm 105. Are attached integrally by welding or the like, and an attachment flat plate 108 for attaching the heating means 106 is attached to the work portion attachment plate 107 via four support members 109. It is attached in parallel.

  Further, a heating means 106 is attached to the surface of the mounting flat plate 108 as shown in FIGS. The heating means 106 includes an air cylinder 111 as a driving means for moving the heating contactor 110 up and down, and a heating contactor 110 attached to the operating rods 112 and 113 of the air cylinder 111 via other members. It is composed of The air cylinder 111 is attached to the surface of the mounting flat plate 108 by screwing or the like, and by supplying pressurized air through the air hoses 114 and 115, the operating rods 112 and 113 are vertically moved by a predetermined amount. And is configured to stop at a predetermined position.

  Further, as shown in FIG. 13, the heating contactor 110 includes upper and lower heating plates formed in a flat plate shape having a predetermined thickness with a metal having high thermal conductivity such as brass, copper, or stainless steel, for example. Parts 116 and 117, and a flat heater 118 made of a band heater or the like attached in a state of being sandwiched between the heating plate parts 116 and 117. Of the heating plate portions 116 and 117, the lower heating plate portion 117 is formed such that a central portion 117a of the lower end surface protrudes downward over a predetermined width, and the protruding portion 117a. As shown in FIG. 13, two convex portions 119 and 120 having a V-shaped cross section are formed adjacent to each other at the center of the lower surface. These two convex sections 119 and 120 having a V-shaped cross section are equal to or slightly longer than the length of the side walls 9 and 10 of the plastic cardboard box 1 at the central portion of the lower end surface of the heating plate section 117. It is formed long along a direction perpendicular to the drawing.

  Further, as shown in FIG. 13, the above-mentioned two convex portions 119 and 120 having a substantially V-shaped cross section have an angle θ ′ of their tip portions 119a and 120a slightly smaller than 90 degrees, for example, an angle of 80 to 85 degrees. The convex portions 119 and 120 are in contact with the surface of the plastic cardboard piece 7 to heat the plastic flat plate 4 and the rib 6 positioned on the surface of the plastic cardboard piece 7. As shown in FIG. 7, it melts to form grooves 21 and 22 having a substantially V-shaped cross section on the surface of the plastic cardboard piece 7. The groove portions 21 and 22 having a substantially V-shaped cross section formed on the surface of the plastic cardboard piece 7 are formed so that the angle θ is approximately 90 degrees. If the angle θ ′ of 120 is set to 90 degrees, there is “escape” of the resin that forms the plastic cardboard piece 7 at the time of heat molding, and the angle θ of the grooves 21 and 22 becomes larger than 90 degrees. .

  Therefore, in this embodiment, the angle θ ′ of the convex portions 119 and 120 having a substantially V-shaped cross section is set in consideration of the “escape” of the resin when the grooves 21 and 22 having a substantially V-shaped cross section are formed. The angle is set to 80 to 85 degrees, which is slightly smaller than 90 degrees. Furthermore, the “escape” of the resin when the grooves 21 and 22 having a substantially V-shaped cross section are formed differs depending on the basis weight (weight per unit area) of the plastic cardboard. For example, the thickness t of the plastic cardboard is Even if the same 4 mm, the weight per unit area (weight per unit area) is 600 g and the weight per unit area is 800 g. Similarly, even if the plastic cardboard thickness t is the same 5 mm, the weight per unit area (unit area) Some have a weight per piece) of 800 g, while others have a weight of 1000 g. Therefore, the amount of “escape” of the resin when the grooves 21 and 22 having a substantially V-shaped cross section are formed on the surface of the plastic cardboard piece 7 varies depending on the basis weight (weight per unit area) of the plastic cardboard. Depending on the “escape” amount of the resin, the angle θ ′ of the convex portions 119 and 120 having a substantially V-shaped cross section is set in the range of an angle of 80 to 85 degrees, for example. Incidentally, the larger the basis weight (weight per unit area) of the plastic cardboard, the smaller the angle θ ′ of the convex portions 119 and 120 is set, that is, the angle close to 80 degrees.

  Furthermore, the position where the side surfaces 119b, 120b located inside the two convex portions 119, 120 intersect is the position where the side surfaces 119c, 120c located outside the convex portions 119, 120 intersect the planes 121, 122. Is also set at an upper position in FIG. 13B and is set to be deeper than the height of the convex portions 119 and 120. Further, the height of the convex portions 119, 120 is set slightly lower than the thickness t of the plastic cardboard piece 7, and even if the convex portions 119, 120 are in the most lowered state, their tips The heights of the portions 119a and 120a are set so as to substantially contact the inner surface of the plastic flat plate 6 located on the back surface of the plastic cardboard piece 7.

  The two convex V-shaped projections 119 and 120 are in contact with the surface of the plastic cardboard piece 7 and the surface of the plastic cardboard piece 7 is heated and melted to form two V-shaped cross sections. When forming the groove portions 21 and 22, the amount of melt deformation due to heating of the plastic corrugated cardboard piece 7 located between the two V-shaped groove portions 21 and 22 in cross section is taken into consideration.

  Further, on both sides of the two inverted V-shaped convex portions 119, 120, flat plate portions 121, 122 are provided so as to be adjacent to each other over a predetermined width, and these flat plate portions 121, 122 are The plastic flat plate 4 adjacent to the surface of the plastic cardboard piece 7 and adjacent to the two V-shaped grooves 21 and 22 is heated and melted.

  Further, as shown in FIG. 11, the upper end portion of the heating plate portion 116 is connected to a connecting member 131 formed in a cylindrical shape via a heat insulating material 130 formed in a disc shape, and The connecting member 131 is connected to a moving member 132 attached to the operating rods 112 and 113 of the air cylinder 111. The connecting member 131 is connected to the moving member 132 attached to the lower ends of the operating rods 112 and 113 of the air cylinder 111 so that the position in the height direction can be adjusted by screws or the like.

  In the first manufacturing apparatus 100 for a plastic cardboard box, as shown in FIG. 7, two V-shaped groove portions 21 and 22 are formed on the surface of the plastic cardboard piece 7, and the two After the surface of the plastic flat plate 4 of the plastic cardboard piece 7 adjacent to the groove portions 21 and 22 having a V-shaped cross section is melted, the folding margins 19 and 20 of the plastic cardboard piece 7 are turned outward as shown in FIG. The process of forming the upper end edges 9a and 10a of the side walls 9 and 10 of the plastic cardboard piece 7 in a double manner by folding is performed manually by an operator. It should be noted that the step of folding the folding margins 19 and 20 of the side walls 9 and 10 of the plastic corrugated cardboard piece 7 in a double manner may be automatically performed.

  Thereafter, similarly, the upper end edges 11a and 12a of the remaining two side walls 11 and 12 of the plastic cardboard box 1 are all bent outward to form a double.

  Then, as shown in FIG. 14, the plastic corrugated cardboard piece 7 in which the folded portions 17 and 18 are provided on the upper edges 9a and 10a of the side walls 9 and 10 as described above is adjacent to each other in a state of being folded into a box shape. The side walls and the joining allowances are joined together by spot welding or the like, and assembled into a box shape.

  Moreover, as shown in FIG. 9, the plastic cardboard piece 7 in which the folded portions are provided on the upper end edges 9a, 10a, 11a, 12a of all the side walls 9, 10, 11, 12 as shown in FIG. In a state of being bent into a box shape, adjacent side walls and joining margins are joined together by spot welding 30 or the like, and assembled into a box shape.

  In the method for manufacturing a plastic cardboard box according to this embodiment, the joining margins between adjacent side walls are joined using a second plastic cardboard box manufacturing apparatus (welding apparatus) as shown below. .

  FIG. 16 shows a second manufacturing apparatus for a plastic cardboard box to which the manufacturing method for manufacturing the plastic cardboard box according to Embodiment 1 of the present invention is applied.

  In FIG. 16, reference numeral 200 denotes a second manufacturing apparatus main body of a plastic cardboard box, and the second manufacturing apparatus main body 200 is formed in a columnar or prismatic shape erected by a leg 201 on the floor surface. Has been. In the upper intermediate portion of the second manufacturing apparatus main body 200, a work table 202 is extended in a flat plate shape having a predetermined width along one side surface along the horizontal direction. The work table 202 is formed in a long shape, and the upper surface of the work table 202 is formed horizontally. Further, a buffer material sheet 203 for fixing the back surface of the work piece is fixed to the upper surface of the work table 202 by means such as adhesion. Note that the cushioning sheet 203 is not necessarily provided.

  Further, at the upper end of the second manufacturing apparatus main body 200 of the plastic corrugated cardboard box, as shown in FIG. 16, a cylinder along the horizontal direction is formed on one side thereof so as to be parallel to the work table 202 described above. A cylindrical work arm 205 having a rectangular shape or cross section is extended. A working portion mounting plate 206 formed in a rectangular shape is integrally attached to the distal end portion of the working arm 205 by welding or the like along the vertical direction. A mounting flat plate 209 for mounting the clamp unit 207 and the welding unit 208 is mounted in parallel to the working unit mounting plate 206 via four support members 210.

  Further, as shown in FIG. 17, a clamp means 207 is attached to the back surface of the mounting flat plate 209. The clamp means 207 includes a first air cylinder 212 as a first drive means for moving the clamp 211 up and down, and a clamp 211 attached to an operating rod 213 of the first air cylinder 212. . The first air cylinder 212 is attached to the back surface of the mounting plate 209 by screwing or the like, and by supplying pressurized air through a hose (not shown), the operating rod 213 is vertically moved by a predetermined amount. It is configured to be movable.

  Further, as shown in FIG. 17, the clamp 211 is formed of a metal plate whose side surface shape is bent in a substantially crank shape, and the tip end portion 211a of the clamp 211 that is bent horizontally is shown in FIG. In addition, in the state where the joining margins of the plastic cardboard pieces 7 are laminated, the welding portion by the welding means 208 is branched into two so as to be pressed and fixed from both sides. Further, the clamp 211 is configured to stop in a state where it is lowered by a predetermined amount (multiple settings are possible) or to stop when the pressing force reaches a predetermined value.

  Further, as shown in FIG. 17, welding means 208 is attached to the surface of the mounting flat plate 209. The welding means 208 is attached to the second air cylinder 215 as a driving means for moving the heating contactor 214 up and down and the operating rods 216 and 217 of the second air cylinder 215 via other members. And a heating contact 214. The second air cylinder 215 is attached to the surface of the mounting flat plate 209 by screws or the like, and by supplying pressurized air through the air hoses 218 and 219, the operating rods 216 and 217 are moved by a predetermined amount. Is moved in the vertical direction and stopped at a predetermined position.

  Further, as shown in FIGS. 17 and 19, the heating contact 214 includes, for example, a heating unit 220 formed in a cylindrical shape with a metal having high thermal conductivity such as brass and copper, and the heating unit 220. It is comprised from the cylindrical heater 221 which consists of a band heater etc. which were coat | covered on the outer periphery. Further, the heating portion 220 has a tip portion 222 formed in a cylindrical shape as shown in FIGS. 20 and 21, and a cross-shaped concave portion is formed on the end surface of the tip portion 222 as shown in FIG. A groove 95 is formed. In addition, it is desirable to apply a release agent such as Teflon (registered trademark) to the end surface 222a of the tip end portion 222 in order to improve the releasability.

  More specifically, as shown in FIGS. 20A to 20C, the tip end portion 222 of the heating unit 220 is configured to be replaceable as a separate welding heat pin 230, and the welding heat pin The tip of 230 is formed in a tapered shape. A plurality of types of heat pins 230 for welding are prepared in accordance with the thickness of the plastic corrugated cardboard 2, and the heat pins 230 for welding are proximal ends screwed to the front end portion 222 of the heating unit 220 on the main body side. It comprises a nut-like threaded portion 231 on the side, an intermediate cylindrical portion 232, and a tapered portion 233 on the distal end side. The length of the tapered portion 233 on the distal end side is variously set according to the thickness of the plastic cardboard 2, and a cross-shaped concave groove 235 is formed on the distal end surface 234. As will be described in detail later with reference to FIG. 22 and the like, the plastic corrugated cardboards 2 can be reliably welded to each other without breaking into a circular shape, while efficiently conducting heat conduction to 2.

  Of course, the tapered welding heat pin 230 may be formed integrally with the distal end portion 222 of the heating unit 220. 20 (d) has a free size regardless of the thickness of the plastic cardboard 2. Moreover, the welding heat pin 230 shown in FIG. 21 is used when welding a corner member so that it may mention later.

  Furthermore, the welding heat pin 230 shown in FIG. 42 has a foaming agent applied to a plastic (synthetic resin) such as polypropylene as shown in FIG. It is a welding hot pin suitable for welding a polypropylene sheet having a foaming ratio of 2 to 6 times composed of a dense surface layer foamed by mixing and minute closed cells.

  Unlike the plastic cardboard, the plastic sheet mixed with the foaming agent is not a space between the front surface layer and the back surface layer, but is composed of a resin layer mixed with the foaming agent. Therefore, as in the case of plastic cardboard, the welding of the front surface layer and the back surface layer is not sufficient in strength, and by providing irregularities in a lattice shape on the front end surface of the welding heat pin 230, the upper plastic sheet The resin layer and the resin layer of the lower plastic sheet can be sufficiently melted and mixed, and sufficient welding strength can be obtained.

  In addition, the plastic sheet mixed with the foaming agent increases the volume of the foaming agent in the resin by foaming at the time of heat welding, so by forming a groove on the outer periphery of the front end surface of the welding heat pin 230, As shown in FIG. 43, the expanded resin can be molded in the concave groove, and the appearance after welding is improved.

  Further, as shown in FIGS. 17 and 19, the upper end portion of the heating unit 220 is connected to the heat insulating material 225 via a connecting member 224 formed in a cylindrical shape, and the heat insulating material 225 includes It is connected to a moving member 227 attached to the operating rods 216 and 217 of the second air cylinder 215 via a connecting member 226 formed in a front inverted T shape. The connecting member 227 is connected to the moving member 227 attached to the lower ends of the operating rods 216 and 217 of the second air cylinder 215 so that the position in the height direction can be adjusted by a screw or the like. Yes.

  Further, as shown in FIG. 17, in the second manufacturing apparatus for a plastic cardboard box, an air injection nozzle 228 is attached to a clamp 211, and air is supplied from the air injection nozzle 228 at a predetermined timing. Is sprayed to the welding position. Note that as the air jetted from the air jet nozzle 228, pressurized air for driving the air cylinder 215 can be used, and the configuration of the apparatus can be simplified.

  In the above configuration, in the manufacturing apparatus to which the plastic sheet box manufacturing method according to this embodiment is applied, a frame member or the like is used to reinforce the opened upper end of the plastic sheet box as follows. Therefore, it is possible to manufacture a plastic cardboard box having a small number of parts and a low cost and having a sufficient strength.

  In addition, in the manufacturing apparatus to which the plastic sheet box manufacturing method according to this embodiment is applied, when the plastic sheets are welded together as described below, the plastic sheets cause so-called “whitening” and have an appearance. It is possible to manufacture a plastic sheet box without lowering the flatness due to lowering or deformation of the plastic sheet due to heat.

  That is, in the method for manufacturing a plastic sheet box according to this embodiment, for example, as shown in FIG. 9, a plastic cardboard piece that has been cut into a predetermined planar shape in which the plastic cardboard box 1 can be assembled in advance. A preparatory process for preparing 7a, 7b, 7c is performed. The plastic cardboard pieces 7a, 7b, 7c are cut into a predetermined plane shape by a press or the like from a sheet of plastic cardboard 2 (not shown) having a predetermined size. At this time, the plastic cardboard pieces 7a, 7b, 7c are cut so that the side walls 11, 12 facing each other are separated from each other, but as shown in FIG. You may comprise so that it may cut integrally.

  Thereafter, the plastic corrugated cardboard piece 7 cut as described above has, as shown in FIG. 7, two side walls 9, 10 and two upper ends of the side walls 11, 12 with V-shaped grooves 21, 22 is formed, and the bent portions 17 and 18 are formed by bending the upper end edges of the side walls 9 and 10 and the side walls 11 and 12.

  Formation of the V-shaped groove portion for the plastic cardboard piece 7 is performed as follows.

  In the plastic cardboard box manufacturing apparatus according to this embodiment, as shown in FIG. 23, one side wall (for example, side wall 9) of the plastic cardboard piece 7 cut as described above is used as the plastic cardboard box. It is placed on the work table 102 of the first manufacturing apparatus main body 100. Thereafter, in the first apparatus for producing a plastic cardboard box, as shown in FIG. 23, the air cylinder 111 is operated to lower the heating contact 110 by a predetermined amount, The plastics of the plastic corrugated cardboard piece 7a in which the tips 119a and 120a of the two convex V-shaped projections 119 and 120 provided on the end surface 117a are located on the outer surface corresponding to the bent portion of the upper end edge 9a of the side wall 9 It abuts on the flat plate 4. The heating contactor 110 is previously heated to a predetermined temperature (for example, 200 to 350 ° C.) by a flat plate heater 118. At that time, as shown in FIGS. 45 and 46, a thin release sheet S having a thickness of about 0.1 mm made of a release material such as Teflon (registered trademark) is provided on the surface of the plastic cardboard piece 7a. It is desirable to intervene. When the tips 119a, 120a of the convex portions 119, 120 having a V-shaped cross section are brought into direct contact with the surface of the plastic cardboard piece 7a, the surface of the convex portions 119, 120 is coated with (registered trademark) or the like. Even so, the air in the plastic cardboard piece 7a is expanded by the heat of the convex portions 119, 120 having the V-shaped cross section, and the plastic cardboard pieces located on the side surfaces of the convex portions 119, 120 by the expanded air. Whereas the shape of 7a is deformed into a wavy shape, when a releasable sheet S having a thickness of about 0.1 mm is interposed, deformation of the plastic cardboard piece 7a due to expanded air The inner surface of the groove having a V-shaped cross section can be formed flat, and the folded portion can be formed beautifully when the groove portion is folded. Kill.

  Then, the flat plate 4 of the plastic corrugated cardboard 2 on the side wall 9 located on the surface is melted by the heat of the two V-shaped convex portions 119 and 120 as shown in FIG. Due to the pressing force of the contact 110, the flat plate 5 of the molten plastic corrugated cardboard 2 is deformed into the same shape as the two convex portions 119, 120 having a V-shaped cross section, and as shown in FIG. The lower end surfaces 121 and 122 of the flat plate portion 117 of the heating contactor 110 are lowered to a state where they are in contact with the plastic flat plate 4 of the plastic cardboard 2.

  At that time, as shown in FIG. 23, the convex portions 119 and 120 having the V-shaped cross section are brought into contact with the flat plate 4 of the plastic corrugated cardboard 2 on the side wall 9 located on the surface by the own weight, and the convex portions having the V-shaped cross section. By heat conduction from the portions 119 and 120, the plastic cardboard 2 is heated and melted to about 4/5 of its thickness.

  Thereafter, the convex portions 119 and 120 having the V-shaped cross section are pushed down as shown in FIG. 24 by a pressure of about 5 times their own weight, so that the thickness of the plastic cardboard 2 is about 4/5. The concave portions 21 and 22 having a V-shaped cross section are formed. At this time, when the thickness of the plastic cardboard 2 is 5 mm, for example, the concave portions 21 and 22 having a V-shaped cross section are formed over a depth of about 4 mm.

  Next, in the first manufacturing apparatus for a plastic cardboard box, as shown in FIG. 24, the plastic flat plate 4 of the plastic cardboard piece 7 on the side wall 9 located on the surface is the flat plate portion of the contact 18 for heating. It is melted by the heat of 117, and this state is maintained for a predetermined time.

  Thereafter, in the first apparatus for producing a plastic cardboard box, as shown in FIG. 24, the flat plate portion 117 of the heating contactor 110 abuts on the plastic flat plate 4 positioned on the surface of the plastic cardboard piece 7. In the state, a predetermined time passes and the plastic flat plate 4 is melted.

  Next, in the first manufacturing apparatus for a plastic cardboard box, as shown in FIG. 25, the plastic cardboard pieces 7a constituting the plastic cardboard box 1 with the heating contactor 110 retracted upward, As shown in FIG. 8, 7b and 7c are the state where the upper end edges 9a, 10a, 11a, and 12a of the side walls 9, 10, 11, and 12 are folded outward, and the inner surfaces of the folded portions 17 and 18 are mutually connected. Welded.

  Next, as shown in FIG. 15, the plastic cardboard pieces 7a, 7b, and 7c have the side walls 9 and 10 provided on the outer periphery of the bottom wall 8 folded and the other side walls 11 and 12 combined. In this state, the plastic cardboard boxes 1 as shown in FIGS. 1 and 2 are manufactured by being joined to each other through joint margins 13, 15, 23... Provided on the side walls 9, 10 and the bottom wall 8. The

  The joining process through the joining margins 13, 15, 23... Provided on the side walls 9, 10 and the bottom wall 8 of the plastic cardboard pieces 7a, 7b, 7c is the second manufacturing of the plastic cardboard box. The following is performed using the apparatus.

  In the second apparatus for manufacturing a plastic cardboard box, the joining margins 13, 15, 23... Of the side walls 9, 10 and the bottom wall 8 of the plastic cardboard box 1 and predetermined positions of the side walls 11, 12 are laminated together. In this state, as shown in FIG. 26, the plastic cardboard box is placed on the work table 202 of the second manufacturing apparatus main body 200. Thereafter, in the second apparatus for producing a plastic cardboard box, as shown in FIG. 26, the first air cylinder 212 is operated to lower the clamp 211 by a predetermined amount, thereby cushioning the work table 202. The side walls 9, 10 and bottom wall 8 of the laminated plastic cardboard pieces 7 placed on the sheet 203 and the side walls 11, 12 are clamped 211 from above. The operation of pressing is performed.

  Thereafter, in the second manufacturing apparatus for the plastic cardboard box, as shown in FIG. 27, the joining margins 13, 15, and 23 of the side walls 9, 10 and the bottom wall 8 of the two plastic cardboard pieces 7 in the laminated state. In a state where the side walls 11 and 12 are pressed from above by the clamp 211, the second air cylinder 215 is operated to lower the heating contact 214 by a predetermined amount, and the tip of the heating contact 214 222 of the joining margin 13 located on the surface among the joining margins 13, 15, 23... And the sidewalls 11, 12 of the side walls 9, 10 and the bottom wall 8 of the two plastic cardboard pieces 7 in the laminated state It contacts with the flat plate 4 of the plastic cardboard 2. The heating contact 214 is preheated to a predetermined temperature (for example, 200 to 350 ° C.) by a cylindrical heater 221.

  Then, the flat plate 4 of the plastic corrugated cardboard 2 having the joining allowance 13 located on the surface is melted by the heat of the heating contactor 18 as shown in FIG. Then, the flat plate 4 of the molten plastic corrugated cardboard 2 is deformed into the same shape as the heating contact 214, and is deformed and lowered into a shape along the tip surface 26a of the heating contact 214, as shown in FIG. To do.

  Next, in the second apparatus for manufacturing a plastic cardboard box, as shown in FIG. 22, the flat plate 4 of the plastic cardboard 2 with the joining allowance 13 located on the surface is melted by the heat of the heating contactor 214. While being deformed, the rib 6 positioned in the middle of the plastic cardboard 2 is also melted by the heat of the heating contactor 214, and the tip 222 of the heating contactor 214 is positioned on the back surface of the plastic cardboard 2. Abut.

  At that time, a predetermined pressure is applied to the heating contact 214 by the second air cylinder 215, and the heating contact 214 is lowered by the predetermined pressure by the second air cylinder 215. The heating contact 214 may be configured to control the lowered position according to time.

  That is, in the second apparatus for manufacturing a plastic cardboard box, the flat plate 4 of the plastic cardboard 2 melts and deforms in a state where the heating contact 214 is in contact with the flat plate 4 surface of the plastic cardboard 2. If the plastic corrugated cardboard 2 is determined, it can be known by an experiment or the like. Therefore, the lowering position of the heating contact 214 can be controlled by the time.

  Thereafter, in the second apparatus for manufacturing a plastic cardboard box, as shown in FIG. 22, in a state where the tip 222 of the heating contactor 214 is in contact with the flat plate 5 located on the back surface of the plastic cardboard 2, As time passes, the flat plate 5 is melted, so that the plastic corrugated cardboard 2 on the side wall 11 located on the back surface side is fused and fixed to the flat plate 4 facing (located on the front side), and the laminated side wall 9 The joining margin 13 and the side wall 11 are welded in a spot shape. In FIG. 22, reference numeral 40 denotes a welded piece of molten plastic cardboard 8.

  Then, the second manufacturing apparatus for the plastic cardboard box retracts the heating contact 214 upward by the second air cylinder 215, and at the welded portion 13 of the laminated side wall 9 and the welded portion of the side wall 11. Air is sprayed from the air nozzle 228 to cool it.

  In the second apparatus for producing a plastic cardboard box, the clamp 211 is retracted upward by the first air cylinder 212, and the welding operation at one place is completed.

  Similarly, as shown in FIG. 15C, the plastic cardboard box 1 is manufactured by welding predetermined portions of the plastic cardboard 2 constituting the plastic cardboard box 1.

  As described above, according to the above-described embodiment, the upper end edges of the side walls 9, 10, 11, and 12 of the plastic cardboard box 1 are welded in a folded state, thereby The end face can be flattened and the upper edge can be doubled to be reinforced, and the upper end of the plastic cardboard box 1 is reinforced. Therefore, it is possible to provide a plastic corrugated cardboard box 1 that can be manufactured at a low cost with a sufficient amount of strength.

  As described above, according to the method and apparatus for manufacturing a plastic cardboard box, the joining portion of the plastic cardboard 2 is not whitened or deformed, and the flatness is not deteriorated. It becomes possible to join the corrugated cardboard 2 with high accuracy.

  The surface of the plastic cardboard box 1 is deformed into a state where the welding position 30 is recessed in a circular shape as shown in FIG. 2, but the inner surface of the plastic cardboard box 2 is maintained flat. Further, the periphery of the welding position is not whitened or deformed so as to be distorted, and it is possible to weld with high accuracy.

  When the welding mark on the surface of the plastic cardboard 2 is anxious, it can be made inconspicuous by applying a tape of the same color as the surface of the cardboard 2. Further, as shown in FIG. 44, the welding trace on the surface of the plastic corrugated cardboard 2 can be made invisible from the outside by fitting the cap member C to the welding trace.

  In the above embodiment, the case where the folded portion of the side wall of the plastic corrugated cardboard box 1 has a predetermined length has been described. However, as shown in FIG. 35, the folded portions 17, 18, etc. of the side walls 9, 10 etc. May be provided up to the lower end over the entire length of the side walls 9, 10, etc.

Embodiment 2
28 and 29 show a second embodiment of the present invention. The same reference numerals are given to the same parts as those in the first embodiment. In the second embodiment, as described above, FIG. It is configured to provide a corner member for stacking plastic cardboard boxes suitable for stacking plastic cardboard boxes configured in the vertical direction.

More specifically, in the second embodiment, a plastic cardboard box is formed in the shape of a box whose upper end surface is opened by plastic cardboard, and at least two of the side walls located on the outer periphery thereof are opposed to each other. In the corner member for stacking plastic cardboard boxes used for stacking up and down, the plastic cardboard boxes configured by folding the upper edge of the side wall outward are doubled.
A fixing portion to be mounted in a state of being fixed to a corner portion of the opened upper end surface of the plastic cardboard box;
A regulation plate having two regulation plates that are provided integrally with the fixed portion and are in contact with two adjacent side walls of a corner located at the lower end of the plastic cardboard box that is stacked on the upper portion;
Of the two restricting plates of the restricting plate portion, the restricting plate that contacts the lower end of the side wall where the upper end edge of the plastic cardboard box is folded outward is more plastic than the restricting plate that contacts the other side surface. It is configured to be displaced inside the cardboard box.

  That is, as shown in FIGS. 1 and 2, the plastic cardboard box configured as described above can be used alone, but this plastic cardboard box 1 is used for industrial products, food products, Alternatively, in order to efficiently store and transport the plastic cardboard box 1 when storing and transporting articles such as daily necessities, a plurality of plastic cardboard boxes 1 are stacked one above the other as shown in FIG. It is often stored and transported in a wet state.

  Therefore, in the plastic cardboard box 1, as shown in FIG. 29, a corner member 50 for stacking made of thermoplastic plastic (synthetic resin) such as polypropylene is attached to the corner of the opened upper end surface. Used in the state. As shown in FIG. 30, the corner member 50 is roughly divided into a fixed portion 51 to be mounted in a state of being fixed to a corner portion of the opened upper end surface of the plastic cardboard box 1, and a single unit with the fixed portion 51. It comprises a regulating plate portion 52 having two regulating plates each abutting against two adjacent side walls of a corner portion provided at the lower end of the plastic cardboard box 1 stacked on top.

  As shown in FIG. 30, the fixing portion 51 is configured to include a recess 53 that is fixed in a state where the side walls are sandwiched at corners of adjacent side walls of the plastic cardboard box 1. The outer sandwiching plate portion 54 and the inner sandwiching plate portion 55 forming the recess 53 are arranged so as to face each other with a width slightly larger than the thickness of the side wall (twice the thickness of the plastic corrugated cardboard 2). It is installed. The outer clamping plate portion 54 is set relatively longer than the inner clamping plate portion 55.

  Further, the upper end surface 56 of the fixing portion 51 is formed flat as shown in FIG. 30C, and the upper end surface 56 of the fixing portion 51 is lower end of the plastic corrugated cardboard box 1 stacked on top. A regulating plate portion 52 having two regulating plates 57 and 58 that respectively abut against two adjacent side walls of the corner portion located at is integrally provided. The two restricting plates 57 and 58 are erected vertically on the upper end surface 56 of the fixing portion 51 so as to intersect each other at right angles via a small R-shaped corner portion 59.

  Further, of the two regulation plates 57, 58, the regulation plate 58 that abuts on the lower ends of the side walls 9, 10 where the upper edge of the plastic corrugated cardboard box 1 is folded outward, as shown in FIG. The restricting plate 57 abutting on the other side surface is displaced inside the plastic cardboard box 1.

  In the above-described embodiment, the other side walls 11 and 12 are also doubled by the upper end edges 11a and 12a being folded outward. However, the other side walls 11 and 12 are usually joined to the joining margin of the one side walls 9 and 10 even when the upper end edges 11a and 12a are folded outward and do not double. Apart from whether or not the upper end surface is formed flat, it is configured to be doubled up to the bottom.

  Therefore, it is not necessary to deliberately displace the regulating plate 58 in contact with the lower ends of the other side walls 11 and 12 inside the plastic cardboard box 1.

  When the plastic cardboard boxes 1 are stacked up and down using the corner member 50 configured as described above, as shown in FIGS. 28 and 29, the corners of the opened upper edge of the plastic cardboard box 1 are used. The corner members 50 are attached to the respective portions by the fixing portions 51. At that time, in the corner member 50, the restricting plate of the restricting plate portion 52 mounted on the side walls 9 and 10 whose upper end edge is folded outward becomes the restricting plate 58 displaced to the inside of the plastic cardboard box 1. To be fitted.

  Further, as shown in FIG. 29, the corner member 50 is attached to the corner of the upper edge of the plastic cardboard box 1, and the side on which the side walls 9, 10 are located differs depending on the position of the corner, As shown in FIG. 31, it is necessary to prepare two types of corner members 50 </ b> A and 50 </ b> B located on the diagonal line of the upper edge of the plastic cardboard box 1.

  The corner member 50 may be detachable from the opening 3 of the plastic cardboard box 1, but may be detached from the plastic cardboard box 1 in the process of transporting the plastic cardboard box 1. As shown in FIGS. 32 and 33, the corner member 50 is preferably used in a state of being fixed to the plastic cardboard box 1 by welding or the like using a second manufacturing apparatus for the plastic cardboard box.

  At that time, as shown in FIG. 34, the corner member 50 is attached with a welding heat pin 230 as shown in FIG. 21 at its tip using the second manufacturing apparatus for a plastic cardboard box. The plastic cardboard 2 is welded to the corners of the upper edges of the side walls 9, 10, 11, 12 of the plastic cardboard box 1 by substantially the same process as the welding of the plastic cardboard 2. The corner member 50 and the side walls 9, 10, 11, 12 of the plastic corrugated cardboard box 1 need not penetrate to the back side of the side walls 9, 10, 11, 12 as shown in FIG. Of course, it may be welded to the plastic cardboard 2 on the surface side of the side walls 9, 10, 11, 12 through the surface of the corner member 50.

  Thus, by using the corner member 50 in which one of the restricting plates 58 is displaced inward as described above, the upper end edges 9a, 10a of the side walls 9, 10 are folded outward to form a double plastic cardboard. As shown in FIG. 28, the box 1 is displaced due to a large gap between the side walls 9, 10 in which the upper edge 9 a, 10 a is doubled and the restriction plate 58 of the corner member 50. Therefore, the plastic cardboard boxes 1 can be reliably stacked up and down.

  FIG. 36 is a configuration diagram showing a modified example of the corner member 50.

  As shown in FIG. 36, in this corner member 50, the height of the restriction plate 57 corresponding to one side wall 11 is set lower than that in the above embodiment, and the plastic cardboard box 1 is moved up and down. When stacking or pulling out the plastic cardboard boxes 1 stacked on top of each other, the regulation plate 57 corresponding to one side wall 11 is set low, and a notch 60 is provided above the regulation plate 57. Therefore, the plastic cardboard box 1 can be easily pushed and pulled out.

  As shown in FIG. 37, the corner member 50 corresponds to only one side wall 11 among the four corner members 50A ′, 50B ′, 50A, 50B attached to the upper end portion of the plastic cardboard box 1. What is necessary is just to apply to corner member 50A ', 50B', and since the other side wall 12 which opposes is that the restriction board 57 is set high similarly to others, the plastic corrugated cardboard box 1 is made by the vibration at the time of conveyance etc. It is possible to prevent deviation.

  Other configurations and operations are the same as those of the above-described embodiment, and thus description thereof is omitted.

Embodiment 3
FIG. 38 shows a third embodiment of the present invention. The same reference numerals are used for the same parts as in the first embodiment, and in this third embodiment, the plastic sheet box is attached to the bottom wall. By connecting the adjacent side walls to each other by means of a detachable coupling means via a joint margin provided on one of the adjacent side walls, It is configured to be disassembled and assembled into a box shape with an open end face.

  FIG. 38 is a front structural view showing a plastic sheet box according to Embodiment 3 of the present invention.

  As shown in FIG. 38, the plastic sheet box 1 has a rectangular parallelepiped shape in which an upper end surface is opened from a bottom wall 8 and four side walls standing around the same, as in the first embodiment. The adjacent side walls can be disassembled and assembled by being joined to each other by a detachable coupling means via a joining margin provided on one of the adjacent side walls.

  As the plastic sheet 2 constituting the plastic sheet box 1, for example, as shown in FIG. 4, a plastic cardboard in which ribs 6 formed in a small cylindrical shape are arranged at regular intervals in the vertical and horizontal directions. 2 is used, but other plastic sheets may be used.

  Further, as shown in FIG. 39, the plastic sheet piece 7 constituting the plastic sheet box 1 is provided on the bottom wall 8 and the periphery thereof, like the plastic cardboard piece 7 shown in FIG. The four side walls 9, 10, 11, 12 are integrally formed, but the joining margins 13, 14, 15, 16 provided on the pair of side walls 9, 10 respectively are those shown in FIG. 6. Is different in that the outer corners 13b, 14b, 15b, and 16b are notched in an R shape. Further, as shown in FIG. 39, the joining margins 13, 14, 15 and 16 are positioned at positions shifted by a slight distance Δ on both sides of the side walls 9 and 10 in consideration of the thickness t of the plastic sheet piece 7. While being configured to be bent, a small gap Δ is provided between the side walls 11 and 12. Further, in the plastic sheet piece 7, bending margins 19, 20, 25, and 26 are provided on all upper end edges of the four side walls 9, 10, 11, and 12, and as shown in FIG. 9a, 10a, 11a, and 12a are bent outward to form a double structure. Furthermore, in this embodiment, unlike the plastic cardboard piece 7 shown in FIG. 9, the bending margins 25 and 26 of the side walls 11 and 12 are provided over the entire width.

  Further, in the third embodiment, the plastic sheet box 1 is configured so as to be disassembled and assembled, and the joining margins 13, 14, 15, 16 of the side walls 9, 10 and the other side wall 11 are configured. , 12 are not joined to each other by spot welding, but are joined to each other by a coupling means such as a detachable snap fit.

  As the detachable coupling means 70, for example, a snap fit or the like is used as shown in FIG. As shown in FIG. 40, the coupling means 70 includes a concave coupling member 71 and a convex coupling member 72 that are relatively engaged with each other, and the concave coupling member 71 and the convex coupling. The member 72 is detachably coupled by being relatively engaged. The coupling means 70 is not limited to this, and any means such as a so-called Velcro (registered trademark) or a combination of a belt and a buckle may be used as long as it is a detachable coupling means. Of course, it may be.

  Of the coupling means 70, the concave coupling member 71 is attached to a predetermined position on the outer surface of the side walls 11 and 12 by means such as welding as shown in FIG. As shown in FIG. 39, the member 72 is attached to a predetermined position on the inner side surface of the joining margin of the side walls 9 and 10 by means such as welding.

  FIG. 41 shows a corner member for stacking plastic sheet boxes used in the plastic sheet box.

  This plastic sheet box volume stacking corner member 50 is basically configured in the same manner as the corner member 50 shown in FIG. 30, but in the third embodiment, the plastic sheet box body 1 is disassembled and assembled. As shown in FIG. 41 (a), the corner member 50 is also provided with a notch 60 at the center corner along the vertical direction and bent at 90 degrees. In addition to the state, as shown in FIG. 41 (b), it is configured to be in a state where it is expanded in a planar shape at 180 degrees through the notch 80.

  That is, as shown in FIG. 41, the corner member 50 has a central corner portion between a fixing portion 51a where the fixing portion 51 is attached to the side walls 9 and 10 and a fixing portion 51b attached to the side walls 11 and 12 side. The restriction plate portion 52 is also divided into a restriction plate portion 52a attached to the side walls 9 and 10 and a restriction plate portion 52b attached to the side walls 11 and 12 side. Yes. In addition, as shown in FIG. 36, the corner member 50 is provided with a hinge portion 61 that connects the fixing portion 51 and the fixing portion 51 so as to be openable and closable at corners outside the fixing portion 51. Via the hinge portion 81, the fixing portion 51 and the fixing portion 51 can be deformed into a state where the fixing portion 51 is bent at 90 degrees and a state where the fixing portion 51 is expanded at 180 degrees.

  Further, as shown in FIG. 40, the corner member 50 has the fixing portions 51 on the side walls 9 and 10 pre-welded to the side walls 9 and 10, and the fixing portions 51 on the side walls 11 and 12 side are free. It is in a state. The fixing portions 51 on the side walls 11 and 12 are fitted and fixed to the upper end portions of the side walls 11 and 12 when the plastic sheet box is assembled.

  When the plastic sheet box constructed as described above is not used, it is stored and transported with the plastic sheet piece 7 unfolded as shown in FIG. As in the case of the box shown in FIG. 14, the plastic sheet box is assembled with the side wall 11 in a state where the four side walls 9, 10, 11, 12 provided around the bottom wall 8 are bent. , 12 are overlapped with the joining margins of the side walls 9, 10 outside, and the coupling means 70 respectively provided at the joining margins of the side walls 11, 12 and the side walls 9, 10 are coupled to each other. The box is assembled as a rectangular parallelepiped box whose upper end surface is fully open.

  When the plastic sheet box 1 is disassembled, the plastic sheet box 1 is disassembled by the reverse procedure of the assembly described above.

  Other configurations and operations are the same as those of the above-described embodiment, and thus description thereof is omitted.

1 is a front view showing a plastic cardboard box as a plastic sheet box according to Embodiment 1 of the present invention. FIG. 2 is an external perspective view showing a plastic cardboard box as a plastic sheet box according to Embodiment 1 of the present invention. FIG. 3 is a perspective view showing a plastic cardboard. FIG. 4 is a perspective view showing a plastic cardboard. FIG. 5 is a sectional view showing a plastic cardboard. FIG. 6 is a plan view showing a plastic sheet piece constituting a plastic cardboard box as a plastic sheet box according to Embodiment 1 of the present invention. FIG. 7 is a cross-sectional configuration diagram showing a V-shaped groove formed along the edge of the plastic sheet piece. FIG. 8 is a cross-sectional configuration diagram showing a folded portion formed at the upper edge of a plastic cardboard box as a plastic sheet box according to Embodiment 1 of the present invention. FIG. 9 is a plan view showing a modification of the plastic sheet piece constituting the plastic cardboard box as the plastic sheet box according to Embodiment 1 of the present invention. FIG. 10 is a block diagram showing a first manufacturing apparatus as a plastic sheet box manufacturing apparatus according to Embodiment 1 of the present invention. FIG. 11 is a configuration diagram showing a main part of a first manufacturing apparatus as a plastic sheet box manufacturing apparatus according to Embodiment 1 of the present invention. FIG. 12 is a configuration diagram showing a main part of a first manufacturing apparatus as a plastic sheet box manufacturing apparatus according to Embodiment 1 of the present invention. FIG. 13 is an enlarged configuration diagram showing a main part of a first manufacturing apparatus as a plastic sheet box manufacturing apparatus according to Embodiment 1 of the present invention. FIG. 14 is a perspective explanatory view showing a method for manufacturing a plastic sheet box according to Embodiment 1 of the present invention. FIG. 15 is a perspective explanatory view showing a method for manufacturing a plastic sheet box according to Embodiment 1 of the present invention. FIG. 16 is a block diagram showing a second manufacturing apparatus as a plastic sheet box manufacturing apparatus according to Embodiment 1 of the present invention. FIG. 17 is a configuration diagram showing a main part of a second manufacturing apparatus as a plastic sheet box manufacturing apparatus according to Embodiment 1 of the present invention. FIG. 18 is a configuration diagram showing the clamp portion. FIG. 19 is an enlarged configuration diagram showing a main part of a second manufacturing apparatus as a plastic sheet box manufacturing apparatus according to Embodiment 1 of the present invention. FIG. 20 is a configuration diagram showing the welding pins. FIG. 21 is a configuration diagram showing a welding pin. FIG. 22 is an explanatory view showing a welding process by the second manufacturing apparatus. FIG. 23 is an explanatory view showing a melting step by the first manufacturing apparatus. FIG. 24 is an explanatory view showing a melting step by the first manufacturing apparatus. FIG. 25 is an explanatory view showing a melting step by the first manufacturing apparatus. FIG. 26 is an explanatory view showing a welding process by the second manufacturing apparatus. FIG. 27 is an explanatory view showing a welding process by the second manufacturing apparatus. FIG. 28 is a configuration diagram showing a state in which plastic sheet boxes are stacked using the corner member according to Embodiment 1 of the present invention. FIG. 29 is a perspective configuration diagram showing a plastic sheet box using the corner member according to Embodiment 1 of the present invention. 30 is a block diagram showing each corner member according to Embodiment 1 of the present invention. FIG. 31 is a configuration diagram showing corner members attached to the four corners of the plastic sheet box. FIG. 32 is a perspective configuration diagram showing a corner portion of a plastic sheet box using the corner member according to Embodiment 1 of the present invention. FIG. 33 is a perspective configuration diagram showing a corner portion of a plastic sheet box using the corner member according to Embodiment 1 of the present invention. FIG. 34 is a configuration diagram showing a welded state of the corner member according to Embodiment 1 of the present invention. FIG. 35 is a block diagram showing a state in which plastic sheet boxes are stacked using corner members according to Embodiment 2 of the present invention. FIG. 36 is a configuration diagram showing each corner member according to Embodiment 2 of the present invention. FIG. 37 is a configuration diagram showing corner members attached to the four corners of the plastic sheet box. FIG. 38 is a block diagram showing a plastic sheet box according to Embodiment 3 of the present invention. FIG. 39 is a plan view showing a plastic sheet piece constituting a plastic sheet box according to Embodiment 3 of the present invention. 40 is a plan view showing an exploded state of the plastic sheet box according to Embodiment 3 of the present invention. FIG. 41 is a configuration diagram showing corner members used in the plastic sheet box according to Embodiment 3 of the present invention. FIG. 42 is a configuration diagram showing another embodiment of the heating pin. FIG. 43 is a schematic view showing a state where welding is performed using the heating pin of FIG. FIG. 44 is a configuration diagram showing a welded portion welded by the second manufacturing apparatus and a cap member for closing the welded portion. FIG. 45 is an explanatory diagram showing an improved example of FIG. FIG. 46 is an explanatory diagram showing an improved example of FIG.

Explanation of symbols

1: Plastic cardboard box, 2: Plastic cardboard, 3: Opening, 9, 10: Side wall, 9a, 10a: Upper edge of side wall, 17, 18: Folded part.

Claims (9)

In a plastic sheet box formed in a box shape with an upper end surface opened by a plastic sheet,
Among the side walls located on the outer periphery of the plastic sheet box, at least the upper end edges of two opposing side walls are folded outward to form a double, and the inner surfaces of the folded parts are welded together Plastic sheet box. The plastic sheet box is composed of a bottom wall and four side walls erected around the bottom wall, and the adjacent side walls are spotted to each other via a joint margin provided on one of the adjacent side walls. The plastic sheet box according to claim 1, wherein the plastic sheet box is formed in a box shape having an upper end surface opened by welding. The plastic sheet box is composed of a bottom wall and four side walls erected around the bottom wall, and the adjacent side walls are attached to and detached from each other via a joining margin provided on one of the adjacent side walls. 2. The plastic sheet box according to claim 1, wherein the plastic sheet box is configured to be freely disassembled and assembled into a box shape having an open upper end surface by joining with a flexible coupling means. 4. The plastic according to claim 1, wherein a corner member for stacking the plastic sheet boxes is fixed to a corner of the upper end surface of the plastic sheet box. Sheet box. In the method for manufacturing a plastic sheet box formed in a box shape having an upper end surface opened by a plastic sheet,
A cutting step of cutting one or more plastic sheet pieces of a predetermined shape formed in a box shape with an upper end surface opened by joining the plastic sheets in a folded state;
When one or more plastic sheet pieces cut by the cutting step are joined in a folded state, a plastic sheet box having an open upper end surface is formed on the outer periphery of the plastic sheet box. Two grooves having a V-shaped cross section for melting in parallel along the upper edge are melted on the outer surface of the plastic sheet piece corresponding to the upper edges of at least two opposing side walls among the side walls positioned. And a melting step of melting the outer surfaces adjacent to both sides of the two groove portions,
By folding the outer surface of the plastic sheet piece corresponding to the upper edge of at least two opposing side walls outward at the position of the two grooves melted by the melting step, the at least two opposing side walls And a fixing step for fixing the melted inner surfaces of the folded portion together. The method for producing a plastic sheet box body, comprising: In a plastic sheet box manufacturing apparatus formed in a box shape with an upper end surface opened by a plastic sheet,
When forming a plastic sheet box having an upper end opened by joining the plastic sheets in a folded state, at least two side walls facing each other among the side walls located on the outer periphery of the plastic sheet box Two convex portions formed by melting two groove portions having a V-shaped cross section for folding back in parallel along the upper end edge on the outer surface of the plastic sheet piece corresponding to the upper end edge, and the 2 A heating contact having a flat plate portion adjacent to both sides of the convex portion of the book;
An apparatus for manufacturing a plastic sheet box, comprising: a moving means for moving the contact for heating in a direction toward and away from the surface of the plastic sheet. When the two convex portions of the heating contact member are melted to form two V-shaped groove portions on the outer surface of the plastic sheet, the convex portion of the heating contact member and the plastic sheet are formed. 7. A plastic sheet box manufacturing apparatus according to claim 6, wherein a thin sheet having releasability is interposed between the two. A plastic sheet box formed in the shape of a box whose upper end surface is opened by a plastic sheet, and among the side walls located on the outer periphery thereof, the upper end edges of at least two opposing side walls are folded outward and doubled. In the corner member for plastic sheet box volume stacking used to stack up and down the plastic sheet box body configured in
A fixing portion to be mounted in a state of being fixed to a corner portion of the opened upper end surface of the plastic sheet box,
A regulation plate having two regulation plates that are provided integrally with the fixed portion and are in contact with two adjacent side walls of a corner located at the lower end of the plastic sheet box stacked on top;
Of the two restricting plates of the restricting plate portion, the restricting plate that contacts the lower end of the side wall where the upper end edge of the plastic sheet box is folded outward is more than the restricting plate that contacts the other side surface. A corner member for volume stacking of plastic sheet boxes, wherein the corner member is displaced inside a plastic sheet box body. The corner member for stacking plastic sheet boxes is configured to be freely developed on members respectively attached to two adjacent side walls located at corners of the plastic sheet box. A corner member for plastic sheet box volume stacking according to 8.

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