Method of manufacturing receiving member for transport container and mold used for method

Abstract

To provide a mold which can be manufactured at low cost and saves storage space, a receiving member for a transport container manufactured by using the mold, and a manufacturing method thereof.SOLUTION: A mold 16 of the present invention includes: a base 19 that is substantially rectangular, has a bottom surface 19b with a recess 19c, and has a first pin 17a and a block 18 mounted thereon; and a bottom plate 20 that is fixed to the base 19 by using a bolt 21a while being fitted into the recess 19c. The base 19 is provided with a plurality of pin insertion holes 19d, each having a circular shape in a plan view, perpendicular to an upper surface 19a. The bottom surface 19b has four corners each having a circular screw hole 19e in a plan view, which is used for screwing the base 19 to another member. The bottom plate 20 is provided with a plurality of through holes 20a each having a circular shape in a plan view at positions corresponding to the pin insertion holes 19d so that a bolt 21b inserted into the pin insertion holes 19d of the base 19 can communicate therethrough.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a support member for a transport container (hereinafter simply referred to as a support member) that fixes products, parts, etc. inside a transport container to prevent them from moving, a manufacturing method thereof, and a mold used therefor, and in particular to a method for inexpensively manufacturing a support member that can be detachably attached to a member that constitutes a transport container. [Background technology]

[0002] Containers (hereinafter referred to as transport containers) used for transporting or transporting products, parts, etc. (hereinafter collectively referred to as "items") often have support members installed to prevent the items from being scratched or broken. These support members may have three-dimensional curved surfaces that conform to the shape of the items so that they can reliably support the items. However, when manufacturing support members with such shapes, it is necessary to produce a wide variety of items in small quantities. Therefore, if these support members are to be manufactured entirely by injection molding, there is the problem that it takes a long time to create the molds, which increases manufacturing costs.

[0003] To address this issue, for example, Patent Document 1 discloses an invention entitled "Motor Receiving Tray and Transfer Set" that relates to a vacuum-formed tray that receives the lower part of a motor used to drive a vehicle. Patent document 1 describes a method for producing a motor receiving tray by placing a heated synthetic resin plate-like member on a heated molding die having a plurality of shaped protrusions, creating a negative pressure inside suction holes in the molding die to form an uneven shape in the plate-like member corresponding to the shaped protrusions, and then removing the cooled plate-like member from the molding die. The motor receiving tray manufactured in this manner has a three-dimensional curved surface formed by vacuum molding that conforms to the shape of the item, which has the advantage of lower manufacturing costs compared to forming the part by methods such as injection molding.

[0004] Furthermore, Patent Document 2 discloses an invention entitled "Product Transport Container" relating to a transport container equipped with a support member for supporting a product. Patent Document 2 describes a method in which a thermoplastic sheet such as polypropylene is heated and softened, and then a metal block is used to form a skin member by deforming it with vacuum pressure using a mold whose structure replicates the shape of the product on the upper surface of a portion of the metal block, and the skin member and a rib plate form the product receiving portion of the transport container. In a transport container with this structure, the three-dimensional recess in the product receiving section that supports the product is formed by vacuum molding, which makes it possible to reduce manufacturing costs compared to forming this part by methods such as injection molding.

[0005] Furthermore, Patent Document 3 discloses an invention entitled "Method for manufacturing a transport container" that relates to a method for manufacturing a transport container in a short period of time that has a three-dimensional receiving material, has a small number of parts, and is easy to separate and dispose of. The invention disclosed in Patent Document 3 is a method for manufacturing a transport container having a frame with a base unit having openings in a pair of side walls arranged vertically at a distance from each other, and a receiving material straddling the base unit and with claw portions that fit into the upper frames of the openings in the pair of side walls.The method is characterized by comprising the steps of: forming a preform by injection molding; a rectangular main molded part that is flat and has raised ribs arranged in a lattice pattern on its surface; a flange part that surrounds the main molded part; a pair of fitting structures that are arranged outside a pair of sides of the main molded part and bend downward in the vertical direction from the flange part at right angles; and claw portions formed on each of the fitting structures; sandwiching the main molded part between a mold and plug prepared for shaping and vacuum-forming the main molded part; and mounting the vacuum-formed preform on the base unit as a receiving material. According to this method of manufacturing a transport container, the support member is attached to the base unit by the preform's joint shape and cross beams, reducing the number of parts that make up the transport container. This also makes it easier to separate and dispose of the support member. Furthermore, when the support member is formed by stretching the main molded portion vertically through vacuum molding, the resin material is supplied to the periphery from the ribs, preventing the main molded portion from becoming extremely thin. As a result, the strength of the support member is improved. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-179883 [Patent Document 2] Patent No. 7007006 [Patent Document 3] Patent No. 7215795 Summary of the Invention [Problem to be solved by the invention]

[0007] Molds used in vacuum forming are processed into the desired shape by cutting a metal or resin block into a three-dimensional shape, but because their structure is less complex than that of molds used in injection molding, their manufacturing costs are not as high. In the motor receiving tray disclosed in Patent Document 1, the transport container disclosed in Patent Document 2, and the transport container disclosed in Patent Document 3, the manufacturing costs of the mold used in vacuum forming are lower than those of the mold used in injection molding, but because the part that comes into contact with the article is formed by a three-dimensional curved surface, even a slight change in the shape due to a change in the specifications of the article requires the mold used in vacuum forming to be remade each time, which poses the problem of increased mold manufacturing costs. Also, to accommodate repeat production, the manufactured molds need to be stored for a certain period of time, but as the number of molds increases, there is also the problem of it becoming difficult to secure storage space.

[0008] The present invention has been made in response to such conventional circumstances, and aims to provide a mold that is inexpensive to manufacture and saves storage space, a receiving member for a transport container manufactured using the mold, and a method for manufacturing the same. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the first invention is a mold for forming a storage item receiving portion having multiple rod-shaped protrusions into a part of a flat plate material of thermoplastic resin by vacuum molding, and is characterized in that it comprises multiple pins consisting of cylindrical or cylindrical bodies, a base in which multiple pin insertion holes that are circular in plan view and are arranged perpendicular to the upper surface, and a bottom plate that is installed on the base so as to close the lower ends of the pin insertion holes, and the bottom plate has through holes arranged parallel to the thickness direction at locations that coincide with the pin insertion holes, and the pins are fixed in a state where their base ends are inserted into the pin insertion holes so that their tip ends protrude from the upper surface of the base. In the first aspect of the present invention, the shape of the item that can be supported by the storage item receiving portion can be determined by changing the length of the pin that protrudes from the top surface of the base. Also, if a screw hole or bolt hole is provided at the lower end of the pin, the pin can be fixed to the base via the bottom plate by threading the tip of a screw or bolt inserted into a through hole in the bottom plate into the screw hole or bolt hole.

[0010] The second invention is characterized in that, in the first invention, the pin comprises a connecting pin having a male threaded portion at its upper end protruding in the longitudinal direction and a female threaded portion at its lower end parallel to the longitudinal direction that screws into the male threaded portion, and a tip pin having a female threaded portion at its lower end parallel to the longitudinal direction. In the second invention, in addition to the effect of the first invention, the overall length of the pin can be easily changed by selecting a connecting pin to be combined with the tip pin from multiple connecting pins of different lengths, or by connecting multiple connecting pins.

[0011] The third invention is characterized in that, in the second invention, a block consisting of a rectangular parallelepiped is provided instead of the tip pin, and this block has a female screw portion formed perpendicular to one of a pair of parallel faces. When a receiving member for a transport container is manufactured using the third invention, the other of the pair of parallel surfaces forms a storage item receiving portion having a flat surface perpendicular to the longitudinal direction of the rod-shaped protrusion.

[0012] The fourth invention is characterized in that, in the second invention, the contour line of the inner wall surface of the through hole is composed of a circular portion having a diameter smaller than the inner diameter of the pin insertion hole and larger than the inner diameter of the female thread portion, and a notch portion provided in a part of the circular portion so as to protrude radially outward from the pin insertion hole. In the fourth invention, in addition to the effect of the second invention, when the tip of a bolt inserted into a through hole in the bottom plate is screwed into the female threaded portion at the lower end of the pin to secure the pin to the base, the air sucked in from the top side of the base during vacuum molding passes through the part of the cutout portion that is not covered by the bolt head and is discharged downward from the bottom side of the base.

[0013] A fifth invention is characterized in that in the first invention, at least a part of the upper surface side of the base has a rounded quadrangle shape with rounded corners in a plan view. In order to ensure close contact between the base and the preform when the base is pressed against it during vacuum molding, it is advisable to recess the top surface of the base into the bottom surface of the preform by a few millimeters, but if the top surface of the base is rectangular in plan view, cracks may occur where the corners come into contact with the preform.In contrast, in the fifth invention, the top surface of the base is rectangular in plan view with rounded corners, which has the effect of making the above-mentioned cracks less likely to occur.

[0014] The sixth invention is a mold for forming a storage item receiving portion having a plurality of rod-shaped protrusions in a part of a flat plate material of thermoplastic resin by vacuum forming, comprising a plurality of pins having a stepped structure made of a cylindrical or cylindrical body, a lower mold having a plurality of pin insertion holes having a stepped structure arranged perpendicular to the upper surface, and an upper mold installed on the upper surface of the lower mold, in which through holes that are circular in plan view and arranged parallel to the thickness direction at locations corresponding to the pin insertion holes, the pin insertion holes consisting of a small diameter hole that is circular in plan view and opens to the bottom surface, and a large diameter hole that is circular in plan view and opens to the top surface, the pin has a small diameter portion made of a cylindrical body whose outer diameter is smaller than the inner diameter of the through hole in the upper mold, and is provided at the tip side, and a large diameter portion whose outer diameter is larger than the inner diameters of the small diameter hole in the lower mold and the through hole in the upper mold, and is provided at the base end side, the large diameter portion of the pin has an outer diameter smaller than the inner diameter of the large diameter hole in the lower mold, and the depth and length of the large diameter hole in the lower mold are equal. In the sixth invention, after placing the large diameter portion of the pin inside the large diameter hole of the pin insertion hole in the lower mold, the upper mold is placed on top of the lower mold so that the small diameter portion of the pin passes through the through hole, and the two are fixed together with a bolt or the like, which makes it impossible for the large diameter portion of the pin to be removed from the large diameter hole of the pin insertion hole in the lower mold, and the pin is fixed to the mold.

[0015] The seventh invention is a support member for a transport container that is installed to secure items stored in the transport container, characterized in that a stored item support portion is provided in a part of a flat plate material made of thermoplastic resin, and the stored item support portion has a plurality of rod-shaped protrusions formed to protrude in one direction. In the seventh invention, the items stored in the transport container are supported by the tip surfaces of the rod-shaped protrusions, and the side surfaces of the rod-shaped protrusions abut against the items, thereby restricting the lateral movement of the items.

[0016] The method for manufacturing a receiving member for a transport container according to the eighth invention is characterized by comprising the steps of forming a flat preform by injection molding of a thermoplastic resin, heating a portion of the preform until it reaches its heat distortion temperature, and forming a storage item receiving portion in a portion of the preform by vacuum molding the heated portion of the preform by pressing a mold according to any one of the first to sixth inventions against the heated portion of the preform. The eighth invention has the effect that the transfer container receiving member according to the seventh invention can be easily manufactured by vacuum forming using the mold according to any one of the first to sixth inventions. [Effects of the Invention]

[0017] According to the first aspect of the present invention, the shape of the stored item receiving portion of the transfer container receiving member can be easily changed by replacing the pins installed in the base with those of a different length or by changing the position at which the pins are installed on the base, thereby reducing manufacturing costs compared to remaking a mold from scratch. Furthermore, by recording the length of the pins and the positions of the pin insertion holes into which the pins are installed, the base can be easily returned to its original state at any time, and the base can be stored with the pins removed from the pin insertion holes. This saves storage space for the mold. Furthermore, in the first invention, because the lower ends of the pins can be fixed to the base via the bottom plate, it is possible to form a flow path between the pin insertion hole and the pin for air to be sucked in from the top surface of the base during vacuum forming. In this case, the manufacturing cost of the mold is reduced compared to when the flow path is provided in a location other than the pin insertion hole in the base or inside the pin.

[0018] According to the second invention, the overall length of the pin can be easily changed, and in addition to the effect of the first invention, even if the specifications of the stored item receiving portion in the transport container receiving member are changed, the overall length of each pin can be adjusted to enable the transport container receiving member to be manufactured quickly and inexpensively, with stored item receiving portions having rod-shaped protrusions of the desired length.

[0019] According to the third invention, it is possible to manufacture a support member for a transport container that has a stored item support portion that has a portion that supports items on a surface, which in addition to the effect of the second invention has the effect of increasing the degree of freedom when designing the stored item support portion of the support member for a transport container.

[0020] In the fourth invention, the through holes in the bottom plate function as a flow path for air sucked from the top surface of the base during vacuum forming, eliminating the need to machine a new flow path into the bottom plate. Therefore, in addition to the effects of the second invention, the fourth invention further enhances the effect of the first invention, namely, reduced mold manufacturing costs.

[0021] According to the fifth invention, cracks are less likely to occur in the preform during vacuum forming, and therefore, in addition to the effect of the first invention, there is an effect that a receiving member for a transfer container can be efficiently manufactured from the preform.

[0022] In the sixth aspect of the invention, since it is not necessary to fix the pins one by one, the time required for installing the pins is reduced, and therefore, according to the sixth aspect of the invention, it is possible to improve the manufacturing efficiency of the mold.

[0023] In the seventh invention, unlike the prior art in which the storage item receiving portion supports the item over its entire surface, the contact area between the item and the storage item receiving portion is small, making it less likely for the stored item to be damaged. Furthermore, since there are fewer restrictions on the shape of the portion of the storage item receiving portion that does not contact the item, it is possible to set the processing precision of that portion lower than that of other portions. This reduces the manufacturing cost of the vacuum forming mold used to form the storage item receiving portion.

[0024] According to the eighth aspect of the present invention, the transfer container receiving member according to the seventh aspect of the present invention can be manufactured inexpensively and efficiently. [Brief explanation of the drawings]

[0025] [Figure 1] 1A and 1B are external perspective views of a receiving member for a transfer container according to an embodiment of the present invention and a preform used in the manufacture thereof, respectively. [Figure 2] 1(a) and 1(b) are a schematic diagram showing the configuration of a thermoforming device used in manufacturing a receiving member for a transport container of the present invention and a flowchart illustrating a manufacturing method of the receiving member for a transport container, respectively. [Figure 3] FIG. 1(a) is an external perspective view of a mold according to a first embodiment of the present invention, and FIG. 1(b) is a view of the mold of FIG. 1(a) as seen from the bottom side. [Figure 4] 3(b) is a diagram showing a state in which the bottom plate is removed, and FIG. 3(b) is a plan view of the bottom plate shown in FIG. 3(b). [Figure 5] 3(a) is a side view of the first pin, the second pin, and the block to be installed in the mold shown in FIG. 3(a), and FIG. 3(b) is a cross-sectional view showing the state in which the first pin, the second pin, and the block are attached to the mold. [Figure 6] FIG. 10(a) is an external perspective view of a mold according to a second embodiment of the present invention, and (b) and (c) are external perspective views of the upper mold and the lower mold shown in FIG. 10(a), respectively. [Figure 7] 6(a) is a side view of the third pin and the fourth pin, (b) is a view of the mold shown in FIG. 6(a) from the bottom side, and (c) is a cross-sectional view showing the state in which the third pin and the fourth pin are attached to the mold. DETAILED DESCRIPTION OF THE INVENTION

[0026] The receiving member for a transfer container of the present invention, its manufacturing method, and the mold used therefor will be specifically described with reference to FIGS. In the following explanation, a support member for a transport container having a structure to be installed on a plate material such as the floor plate of the transport container is given as an example, but the manufacturing method and mold for a support member for a transport container of the present invention can also be applied to the case of manufacturing a support member for a transport container having a structure to be installed on a square pipe that constitutes the frame of the transport container, such as the support member for a transport container disclosed in Patent Document 3. In other words, even when vacuum forming is performed using the mold of the present invention on the main molded part of the preform disclosed in Patent Document 3, the functions and effects of the support member for a transport container of the present invention, the manufacturing method thereof, and the mold used therefor, which will be described below, are similarly exerted. Furthermore, in this specification, expressions such as "upper surface" and "lower surface" are used to describe the receiving member for a transport container and the mold used in manufacturing the same, assuming the state in which they are actually used. [Example]

[0027] 1(a) and 1(b) are external perspective views of a receiving member for a transfer container according to an embodiment of the present invention (hereinafter referred to as receiving member 1) and a preform 13 used in the manufacture of the same. Note that Fig. 1(a) shows the receiving member 1 as viewed from the second surface 13b side, and Fig. 1(b) shows the preform 13 as viewed from the first surface 13a side. The preform 13 is made of a plate material that is formed by injection molding of a thermoplastic resin such as polyester, polyolefin, polyamide, or polycarbonate and has a generally rectangular shape in plan view, and is equipped with a molding target portion 2 in which a storage item receiving portion 1a (see FIG. 1(a)) is formed by vacuum molding, a boundary portion 3 (see FIG. 1(a)) that surrounds the molding target portion 2 and is provided so as to protrude from a second surface 13b (see FIG. 1(a)), and a first joint portion 4 and a second joint portion 10 that are provided outside the boundary portion 3 and have side surfaces 13c and 13d that correspond to two parallel sides that form the rectangle. Furthermore, on the first surface 13a of the preform 13, at locations that correspond to the thickened portion due to the provision of the boundary portion 3 (see FIG. 1(a)) on the second surface 13b (see FIG. 1(a)), recesses 3a, 3a that are rectangular in plan view are provided symmetrically, sandwiching the molding target portion 2 therebetween. In the receiving member 1, tiny circular depressions 1b are formed in the molding target portion 2 in places where the stored item receiving portions 1a are not formed, but these are formed by sucking air between the mold and the first surface 13a of the molding target portion 2 during vacuum molding, and can be made less noticeable by adjusting the height of the second pins 17b. Also, by deliberately making the second pins 17b higher than the upper surface 19a of the base 19 and providing circular protrusions, the strength of the molding target portion 2 can be increased and distortion can be prevented.

[0028] The first connecting portion 4 comprises a rectangular seat plate 4a in a plan view, and a protrusion 5 and protrusions 6 and 7 provided on a first surface 13a of the seat plate 4a, with circular through holes 8a provided on the seat plate 4a near side surfaces 13e and 13f that are perpendicular to side surfaces 13c and 13d. The protrusion 5 comprises a pair of side panels 5a that are perpendicular to the seat plate 4a and parallel to the side surface 13c, a flat top panel 5c that connects the upper ends of the pair of side panels 5a and is parallel to the first surface 13a, a pair of side panels 5b that are perpendicular to the seat plate 4a and connect the top panel 5c to the pair of side panels 5a, and four reinforcing panels 5d that are parallel to the side panels 5b and connect the pair of side panels 5a. A pair of openings 9 are provided in the protrusion 5 at locations where the reinforcing panels 5d are not provided. The opening 9 has a portion of the inner wall surface corresponding to one of the long sides of the rectangle cut out in plan view, so that a pair of locking portions 9a, 9a are formed on the side farther from the molding target part 2. The upper surface plate 5c of the protruding part 5 has protrusions 6 on both ends in the longitudinal direction and a protrusion 7 in approximately the center.

[0029] Circular through-holes 8b are provided in the seat plate 10a of the second connecting portion 10 near the side surfaces 13e and 13f, respectively. A pair of locking pieces 11b, 11b, which protrude in a direction perpendicular to the side surface 13d, are rectangular in plan view, and are divided into two by a slit 11a, and are provided in approximately the center of the seat plate 10a in the width direction (the direction perpendicular to the side surfaces 13e and 13f). In addition, a pair of slits 10b, 10b, each having a predetermined length in the direction perpendicular to the side surface 13d, are provided in the seat plate 10a of the second connecting portion 10 between the pair of through-holes 8b, 8b, with the pair of engaging claws 12, 12 sandwiched therebetween.

[0030] 1(a), the structure of the receiving member 1 is the same as that of the preform 13, except that it has a storage item receiving portion 1a. Therefore, when the receiving member 1 and the preform 13 are joined, the protrusion 6 of the preform 13 abuts against the side surface 13d of the receiving member 1, and the protrusion 6 of the receiving member 1 abuts against the side surface 13d of the preform 13. That is, the receiving member 1 and the preform 13 have a structure in which the projections 6 abut against the side surfaces 13d, thereby restricting the movement of each other in a direction perpendicular to the side surfaces 13d.

[0031] The upper surface plate 5c of the protruding portion 5 is formed with a protruding portion 7 consisting of a straight portion parallel to the longitudinal direction thereof and three protruding portions provided at both ends and approximately in the center of this straight portion so as to be perpendicular to the longitudinal direction. As described above, when the receiving member 1 and the preform 13 are joined, the protruding portion provided approximately in the center of the straight portion of one protruding portion 7 is disposed inside one slit 11a, and one locking piece 11b is disposed between the two protruding portions provided at the ends and approximately in the center of the straight portion of the other protruding portion 7. In other words, the receiving member 1 and the preform 13 are structured such that the movement of each of them in directions parallel to and perpendicular to the side surface 13d is restricted by one of the locking pieces 11b being positioned between two protruding portions provided at the end and approximately the center of the straight portion of the other protrusion portion 7.

[0032] The receiving member 1 and the preform 13 are fixed to both sides of the plate material, such as the bottom plate of a transport container, by engaging the engaging claw 12 of one side with the opening 9 of the protruding portion 5 of the other side through a through hole provided in the plate material, with the first surface 13a facing the plate material. However, in the receiving member 1 and the preform 13, the openings 9 of the protruding portions 5 and the engaging claws 12 are arranged symmetrically across the molding target portion 2, so when one engaging claw 12 engages with the opening 9 of the other protruding portion 5, the other engaging claw 12 also simultaneously engages with the opening 9 of the one protruding portion 5. In other words, the preform 13 has a structure that allows it to be easily attached to a plate material such as the bottom plate of a transport container by combining it with the receiving member 1 manufactured from it.

[0033] 1(a), the stored item receiving portion 1a of the receiving member 1 has a plurality of rod-shaped protrusions 1c formed to protrude in one direction. Therefore, when the receiving member 1 is placed inside a transport container, the stored items are supported by the tip surfaces of the rod-shaped protrusions 1c, and the side surfaces of the rod-shaped protrusions 1c come into contact with the items, thereby restricting lateral movement of the items. Unlike conventional technology in which the storage item receiving portion 1a supports the item over its entire surface, the receiving member 1 has a small contact area between the item and the storage item receiving portion 1a, making it less likely for the stored item to be damaged. Furthermore, since there are fewer restrictions on the shape of the portion of the storage item receiving portion 1a that does not contact the item, the processing precision of this portion can be set lower than that of other portions. Therefore, the receiving member 1 with the above structure can reduce the manufacturing costs of the vacuum forming mold used to form the storage item receiving portion 1a.

[0034] Here, the manufacturing method of the receiving member 1 will be described with reference to Fig. 2. Fig. 2(a) and Fig. 2(b) are a schematic diagram showing the configuration of a thermoforming device 14 used in manufacturing the receiving member 1 and a flowchart for explaining the manufacturing method of the receiving member 1, respectively. 2(a), in addition to a heating booth and fasteners (not shown), the thermoforming device 14 is equipped with a plug 15 and a mold 16. The plug 15 is a member for pressing the molded part 2 from above to bring the molded part 2 into close contact with the mold 16, and is arranged above the preform 13 which is fixed to the thermoforming device 14 using fasteners so as to be approximately horizontal. On the other hand, the mold 16 is equipped with a plurality of first pins 17a which are installed so as to protrude upward, and is arranged below the preform 13. The plug 15 may not be used.

[0035] As shown in FIG. 2(b), first, a substantially rectangular preform 13 is formed by injection molding a thermoplastic resin (step S1). Next, the preform 13 is placed in a heating booth (not shown) of a thermoforming device 14, and the molding target part 2 is heated until it reaches a predetermined heat distortion temperature (step S2). After the heated preform 13 is placed in the thermoforming device 14, the mold 16 is pressed from below against the first surface 13a (see FIG. 1(b)) of the molding target part 2 while suctioning air present in the space between the preform 13 and the mold 16, and the plug 15 is pressed from above against the second surface 13b (see FIG. 1(a)) of the molding target part 2 (step S3). Finally, the preform 13 is sufficiently cooled and then removed from the thermoforming device 14 (step S4). According to this method, the receiving member 1 can be easily manufactured by vacuum forming using the mold 16, and therefore the manufacturing cost of the receiving member 1 can be reduced and the manufacturing efficiency can be increased.

[0036] Next, a mold used when manufacturing the receiving member 1 from the preform 13 will be described with reference to Figures 3 to 5. Figure 3(a) is an external perspective view of the mold 16 according to the first embodiment of the present invention, and Figure 3(b) is a view of the mold 16 of Figure 3(a) as seen from the bottom side. Also, Figure 4(a) is a view showing the state in Figure 3(b) with the bottom plate 20 removed, and Figure 4(b) is a plan view of the bottom plate 20 shown in Figure 3(b). In addition, in Figs. 3(a) and 3(b) and Figs. 4(a) and 4(b), in order to avoid the drawings becoming complicated, reference numerals are given to only some of the pin insertion holes and through holes.

[0037] 3(a) and 3(b), the aluminum mold 16 is substantially rectangular parallelepiped and includes a base 19 having a recess 19c in its bottom surface 19b and on which the first pin 17a, the second pin 17b (see FIG. 5(a)) and the block 18 are mounted, and a bottom plate 20 that is fitted into the recess 19c and fixed to the base 19 with bolts 21a. The base 19 is provided with a plurality of pin insertion holes 19d that are circular in plan view and perpendicular to the top surface 19a, and the four corners of the bottom surface 19b are provided with screw holes 19e that are circular in plan view and are used to screw the base 19 to another member. On the other hand, the bottom plate 20 has a plurality of through holes 20a, which are circular in plan view and parallel to the thickness direction at locations that coincide with the pin insertion holes 19d, so that bolts 21b inserted into the pin insertion holes 19d of the base 19 can be communicated with.

[0038] When vacuum forming is performed using the mold 16, it is preferable to recess the top surface 19a of the base 19 into the first surface 13a of the preform 13 by several millimeters (see FIG. 2(a)) so that the base 19 and the preform 13 are tightly attached when pressed against each other. However, if the top surface 19a of the base 19 is rectangular in plan view, cracks may occur at the corners where the base 19 comes into contact with the preform 13. In contrast, at least a portion of the top surface 19a of the base 19 has a rounded rectangular shape in plan view, with the four corners of the rectangle rounded (see FIG. 3(a)). Therefore, the mold 16 makes it difficult for the above-mentioned cracks to occur during vacuum forming. Therefore, the mold 16 allows the receiver member 1 to be efficiently manufactured from the preform 13.

[0039] As shown in FIG. 4(a), the base 19 has a circular shape in plan view, and is provided with bolt holes 19f for fixing the bottom plate 20 with bolts 21a at four positions in the recess 19c near the screw holes 19e. 4(b), in plan view, the contour line of the inner wall surface of the through hole 20a is composed of a circular portion 22a having a diameter smaller than the inner diameter of the pin insertion hole 19d and larger than the inner diameter of the female screw portion 23b (see FIG. 5(a)), and a pair of cutout portions 22b, 22b provided at positions corresponding to both ends of the diameter of the circular portion 22a so as to protrude radially outward from the pin insertion hole 19d. Note that there may be only one cutout portion 22b. The bottom plate 20 is provided with a notch 20b at a position that coincides with the bolt hole 19f when the bottom plate 20 is fitted into the recess 19c of the base 19. It is desirable that the bolt 21b used in the bottom plate 20 of the above structure has a head of a size that exposes at least a portion of the pair of cutout portions 22b, 22b when the bolt 21b is inserted into the through hole 20a (see Figure 3(b)).

[0040] Fig. 5(a) is a side view of the first pin 17a, the second pin 17b, and the block 18 to be installed in the mold 16 shown in Fig. 3(a), and Fig. 5(b) is a cross-sectional view showing the state in which the first pin 17a, the second pin 17b, and the block 18 are attached to the mold 16. Fig. 5(b) shows the state in which the mold 16, the first pin 17a, the second pin 17b, and the block 18 are cut by a plane passing through the central axis of the pin insertion hole 19d. In addition, in Figure 5(b), in order to avoid the illustration becoming too complicated, only some of the male threaded portion 23a and female threaded portion 23b of the connecting pin 23, the female threaded portion 24a of the tip pin 24, the female threaded portion 18a of the block 18, and the through hole 20a of the bottom plate 20 are marked with symbols, and the state in which the bolt 21b is attached to only one first pin 17a is shown, with the bolts 21b not being shown for the other first pins 17a and second pins 17b.

[0041] As shown in Figures 5(a) and 5(b), the first pin 17a is composed of a connecting pin 23 and a tip pin 24. The connecting pin 23 is a cylindrical body with a male thread portion 23a at its tip that protrudes in the longitudinal direction, and a female thread portion 23b at its base end that is parallel to the longitudinal direction and that screws with the male thread portion 23a of the bolt 21b or another connecting pin 23. The tip pin 24 is a cylindrical body with a female thread portion 24a that is parallel to the longitudinal direction and that screws with the male thread portion 23a of the bolt 21b or connecting pin 23, and there are two types of tip pins: one with a pointed tip and one with a flat surface at the tip that is perpendicular to the longitudinal direction. The second pin 17b is a cylindrical body whose length is equal to the depth of the pin insertion hole 19d and in which a female screw portion 23b that screws into the bolt 21b is provided parallel to the longitudinal direction, and is structured so that it can be installed inside the pin insertion hole 19d in the base 19 for the purpose of blocking the pin insertion hole 19d. The connecting pin 23 and the tip pin 24 are not limited to being cylindrical, but may also be cylindrical, prismatic, or rectangular tubular. However, if the tip pin 24 is a prismatic or rectangular tubular member, cracks may occur in the molding target portion 2 of the preform 13 that comes into contact with the corners of the tip surface of the tip pin 24 during vacuum molding, so it is desirable that the tip pin 24 be a cylindrical or cylindrical member.

[0042] The first pin 17a of the above structure has the effect that the overall length can be easily changed by using connecting pins 23 of different lengths to be combined with tip pin 24, or by combining multiple connecting pins 23, and the shape of the tip can also be easily changed by changing the type of tip pin 24. Therefore, by using a mold 16 equipped with such first pins 17a, even if the specifications of the stored item receiving portion 1a in the receiving member 1 are changed, it is possible to quickly and inexpensively manufacture a receiving member 1 equipped with stored item receiving portion 1a having rod-shaped protrusions 1c of the desired length (see Figure 1(a)) by adjusting the overall length of each first pin 17a.

[0043] Block 18 is a rectangular parallelepiped in which a pair of female threaded portions 18a, 18a that thread onto male threaded portion 23a of connecting pin 23 are arranged perpendicular to one surface 18c of a pair of parallel surfaces 18b, 18c, and is configured so that a pair of connecting pins 23, 23 that are connected by threading male threaded portion 23a into female threaded portion 18a can be simultaneously inserted into two pin insertion holes 19d that are arranged consecutively in base 19. When receiver member 1 is manufactured using mold 16 equipped with block 18 having such a structure, surface 18b forms stored item receiver portion 1a having a flat surface that is perpendicular to the longitudinal direction of rod-shaped protrusion 1c. This has the advantage of increasing the degree of freedom in designing stored item receiver portion 1a of receiver member 1.

[0044] 5(b), the first pin 17a, the second pin 17b, and a pair of connecting pins 23, 23 connected to the block 18 are fitted into the recesses 19c and fixed to the base 19 by threading a bolt 21b into the female thread portion 23b through a through hole 20a of a bottom plate 20 fixed to the base 19 using a bolt 21a. Therefore, by making the outer diameter of the connecting pin 23 smaller than the inner diameter of the pin insertion hole 19d of the base 19, it is possible to form a flow path between the connecting pin 23 and the pin insertion hole 19d for air sucked from the upper surface 19a of the base 19 during vacuum molding. In this case, the manufacturing cost of the mold 16 can be reduced compared to when the flow path is provided in a location other than the pin insertion hole 19d in the base 19 or inside the first pin 17a or the second pin 17b. As already mentioned, the pair of cutouts 22b, 22b of the through-hole 20a can be at least partially exposed when the bolt 21b is inserted into the through-hole 20a. In this case, air sucked from the top surface 19a of the base 19 during vacuum forming passes through the portion of the cutout 22b that is not covered by the head of the bolt 21b and is discharged downward from the bottom surface 19b of the base 19. In this way, since there is no need to newly machine the above-mentioned air flow path in the bottom plate 20 in the mold 16, manufacturing costs can be reduced.

[0045] Furthermore, in mold 16, the shape of the item that can be supported by storage item receiving portion 1a is determined by changing the length of first pin 17a protruding from upper surface 19a of base 19. That is, in mold 16, the shape of storage item receiving portion 1a of receiving member 1 can be easily changed by replacing first pin 17a installed on base 19 with one of a different length or by changing the position at which first pin 17a is installed on base 19. This reduces manufacturing costs compared to remaking a mold from scratch. Also, by recording the length of first pin 17a and the position of pin insertion hole 19d where first pin 17a is installed, the base 19 can be easily restored to its original state at any time. Therefore, base 19 can be stored with first pin 17a removed from pin insertion hole 19d. That is, unlike conventional molds, mold 16 does not require storing all molds manufactured to accommodate repeat production. Therefore, mold 16 can save storage space. [Example]

[0046] Fig. 6(a) is an external perspective view of a mold 25 according to a second embodiment of the present invention, and Figs. 6(b) and 6(c) are external perspective views of the upper mold 26 and the lower mold 27 shown in Fig. 6(a), respectively. Fig. 7(a) is a side view of the third pin 17c and the fourth pin 17d, Fig. 7(b) is a view of the mold 25 as seen from the bottom side, and Fig. 7(c) is a cross-sectional view showing a state in which the third pin 17c and the fourth pin 17d are attached to the mold 25. Fig. 7(c) shows a state in which the mold 25, the third pin 17c, and the fourth pin 17d are cut by a plane passing through the central axes of the pin insertion hole 28 and the through-hole 26a. In addition, in Figures 6(a) to 6(c) and Figures 7(b) and 7(c), in order to avoid the figures becoming too complicated, only some of the through holes 26a, pin insertion holes 28, large diameter holes 32, and small diameter holes 33 are labeled with symbols. As shown in Figures 6(a) to 6(c), the aluminum mold 25 is approximately rectangular parallelepiped and comprises a lower mold 27 on which the third pin 17c and the fourth pin 17d (see Figure 7(a)) are installed, and a rectangular plate-shaped upper mold 26 which is installed on the upper surface 27a of the lower mold 27 and fixed to the lower mold 27 using bolts (not shown). Lower mold 27 has a plurality of stepped pin insertion holes 28 formed perpendicular to top surface 27a, and bolt insertion holes 27c each having a circular shape in plan view are formed at each of the four corners so as to penetrate from top surface 27a to bottom surface 27b. Parts of the four corners of lower mold 27 are cut out so that the portions of bolt insertion holes 27c that open to bottom surface 27b form a right-angled isosceles triangle in plan view. The upper mold 26 has a plurality of through holes 26a each having a circular shape in plan view at positions corresponding to the pin insertion holes 28, so that the third pin 17c and the fourth pin 17d (see FIG. 7(a)) inserted into the pin insertion holes 28 of the lower mold 27 can communicate therethrough. In addition, the four corners of the upper mold 26 have bolt insertion holes 26b each having a circular shape in plan view at positions corresponding to the pin insertion holes 28, so that the bolts (not shown) inserted into the bolt insertion holes 27c of the lower mold 27 can communicate therethrough.

[0047] As shown in Figure 7(a), the third pin 17c, which has a stepped structure, is composed of a small-diameter portion 29, which has a pointed tip 29a and is made up of a cylindrical body with an outer diameter smaller than the inner diameter of the through-hole 26a of the upper mold 26, and a large-diameter portion 30, which is made up of a cylindrical body with an outer diameter larger than that of the small-diameter portion 29.The fourth pin 17d, which also has a stepped structure, is composed of a small-diameter portion 31, which is made up of a cylindrical body with an outer diameter equal to that of the small-diameter portion 29 and a shorter length than the small-diameter portion 29, and the large-diameter portion 30. The third pin 17c may have a small diameter portion 29 that is cylindrical like the small diameter portion 31, having a flat surface perpendicular to the longitudinal direction, instead of having a pointed tip 29a.

[0048] As shown in Figures 7(b) and 7(c), the pin insertion hole 28 of the lower mold 27 is circular in plan view, opens to the top surface 27a, has an inner diameter larger than the inner diameter of the through hole 26a of the upper mold 26, and is composed of a large-diameter hole 32 having a depth equal to the length of the large-diameter portions 30 of the third pin 17c and the fourth pin 17d, and a small-diameter hole 33 opening to the bottom surface 27b. The large diameter portions 30 of the third pin 17c and the fourth pin 17d have outer diameters smaller than the inner diameter of the large diameter holes 32 of the pin insertion holes 28, and the small diameter portions 29 of the third pin 17c and the small diameter portions 31 of the fourth pin 17d have outer diameters smaller than the inner diameter of the through holes 26a of the upper mold 26. In other words, the mold 25 is configured so that air sucked from the upper surface 26c (see FIG. 7(c)) of the upper mold 26 during vacuum forming passes through gaps between the third pin 17c or the fourth pin 17d and the through holes 26a and the pin insertion holes 28, and is discharged downward from the bottom surface 27b of the lower mold 27.

[0049] Since the inner diameter of the small diameter hole 33 of the pin insertion hole 28 of the lower mold 27 is smaller than the outer diameter of the large diameter portion 30 of the third pin 17c and the fourth pin 17d, when the large diameter portion 30 of the third pin 17c and the fourth pin 17d is positioned inside the large diameter hole 32 of the pin insertion hole 28 as shown in Figure 7(c), the third pin 17c and the fourth pin 17d will not slip through the small diameter hole 33 of the pin insertion hole 28 and fall out of the mold 25. Furthermore, since the inner diameter of the through-hole 26a of the upper mold 26 is smaller than the outer diameter of the large-diameter portions 30 of the third pin 17c and the fourth pin 17d, after the large-diameter portions 30 of the third pin 17c and the fourth pin 17d are placed inside the large-diameter holes 32 of the pin insertion holes 28 as shown in FIG. 7(c), the upper mold 26 is placed on the upper surface 27a of the lower mold 27 so that the small-diameter portions 29 of the third pin 17c and the small-diameter portions 31 of the fourth pin 17d pass through the through-hole 26a, and then the two are fixed with bolts. This makes it impossible for the large-diameter portions 30 to be removed from the large-diameter holes 32 of the pin insertion holes 28 of the lower mold 27, and the third pin 17c and the fourth pin 17d are fixed to the mold 25. That is, unlike the structure of mold 16 in which first pins 17a and second pins 17b are fixed one by one using bolts 21b, mold 25 has a structure in which third pin 17c and fourth pin 17d are fixed to lower mold 27 at once by the simple action of placing upper mold 26 on top surface 27a of lower mold 27. This reduces the time required for the task of placing third pin 17c and fourth pin 17d on lower mold 27. Therefore, mold 25 can improve manufacturing efficiency. [Industrial Applicability]

[0050] The support member for a transport container of the present invention is installed inside a transport container to support parts or products, and the manufacturing method of the support member for a transport container of the present invention and the mold used therefor can be used when manufacturing the support member for a transport container. [Explanation of symbols]

[0051] REFERENCE SIGNS LIST 1...receiving member 1a...storage item receiving portion 1b...recess 1c...rod-shaped protrusion 2...molding target portion 3...boundary portion 3a...thickness recess 4...first connecting portion 4a...seat plate 5...protruding portion 5a, 5b...side plate 5c...upper plate 5d...reinforcing plate 6, 7...projection portion 8a, 8b...through hole 9...opening 9a...locking portion 10...second connecting portion 10a...seat plate 10b...slit 11a...slit 11b...locking piece 12...engaging claw 13...preform 13a...first surface 13b...second surface 13c-13f...side surface 14...thermoforming device 15...plug 16...mold 17a...first pin 17b...second pin 17c...third pin 17d...fourth pin 18...Block 18a...Male thread portion 18b, 18c...Surface 19...Base 19a...Top surface 19b...Bottom surface 19c...Recess 19d...Pin insertion hole 19e...Screw hole 19f...Bolt hole 20...Bottom plate 20a...Through hole 20b...Notch 21a, 21b...Bolt 22a...Circular portion 22b...Notch portion 23...Connecting pin 23a...Male thread portion 23b...Female thread portion 24...Tip pin 24a...Female thread portion 25...Mold 26...Upper mold 26a...Through hole 26b...Bolt insertion hole 26c...Top surface 27...Lower mold 27a...Top surface 27b...Bottom surface 27c...Bolt insertion hole 28...Pin insertion hole 29...Small diameter portion 29a...Tip 30...Large diameter hole 31...Small diameter hole 32...Large diameter hole 33...Small diameter hole

Claims

1. A mold for forming a storage item receiving portion having a plurality of rod-shaped protrusions in a part of a flat plate material of a thermoplastic resin by vacuum forming, A plurality of pins each having a cylindrical or columnar body; a base having a plurality of pin insertion holes each having a circular shape in a plan view and perpendicular to an upper surface thereof; a bottom plate installed on the base so as to close a lower end of the pin insertion hole, The bottom plate has a through hole formed parallel to a thickness direction at a position corresponding to the pin insertion hole, The mold is characterized in that the pin is fixed with its base end inserted into the pin insertion hole so that its tip end protrudes from the upper surface of the base.

2. The mold according to claim 1, characterized in that the pin comprises a connecting pin having an upper end with a male threaded portion protruding in the longitudinal direction and a lower end with a female threaded portion that screws into the male threaded portion and is parallel to the longitudinal direction, and a tip pin having a lower end with the female threaded portion parallel to the longitudinal direction.

3. A block made of a rectangular parallelepiped is provided instead of the tip pin, 3. The mold according to claim 2, wherein the block has a pair of parallel surfaces, and the female screw portion is formed perpendicular to one of the surfaces.

4. 3. The mold according to claim 2, characterized in that a contour line of an inner wall surface of the through hole, when viewed in a plane, is composed of a circular portion having a diameter smaller than an inner diameter of the pin insertion hole and larger than an inner diameter of the female thread portion, and a notch portion provided in a part of the circular portion so as to protrude radially outward from the pin insertion hole.

5. The mold according to claim 1 , wherein at least a portion of the upper surface of the base has a rounded rectangular shape with rounded corners in a plan view.

6. A mold for forming a storage item receiving portion having a plurality of rod-shaped protrusions in a part of a flat plate material of a thermoplastic resin by vacuum forming, A plurality of pins having a stepped structure made of a cylindrical or cylindrical body; a lower die having a plurality of stepped pin insertion holes formed perpendicular to an upper surface thereof; an upper die having a through hole having a circular shape in a plan view and parallel to a thickness direction at a position corresponding to the pin insertion hole, the upper die being placed on the upper surface of the lower die; the pin insertion hole is composed of a small diameter hole having a circular shape in a plan view and opening to the bottom surface side, and a large diameter hole having a circular shape in a plan view and opening to the top surface side, the pin has a small diameter portion formed of a cylinder having an outer diameter smaller than the inner diameter of the through hole of the upper die at a tip end side, and a large diameter portion having an outer diameter larger than the inner diameters of the small diameter hole of the lower die and the through hole of the upper die at a base end side, A mold comprising: a large diameter portion of the pin having an outer diameter smaller than an inner diameter of the large diameter hole of the lower mold; and a length equal to a depth of the large diameter hole of the lower mold.

7. A receiving member for a transport container that is installed to fix an item stored in the transport container, A storage item receiving portion is provided on a part of the flat plate material of thermoplastic resin, A receiving member for a transport container, wherein the stored item receiving portion has a plurality of rod-shaped projections formed so as to protrude in one direction.

8. forming a flat preform by injection molding of a thermoplastic resin; heating a portion of the preform until it reaches a heat distortion temperature; and forming the item receiving portion in a part of the preform by vacuum molding the mold described in any one of claims 1 to 6 against the heated portion of the preform.

Images