JP2006273348A - Manufacturing method for transportation pallet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a transportation pallet enabling easy and highly productive manufacturing of the pallet that has a bottom board made of a metal plate, a peripheral frame made of a resin, and is light in weight, but is highly strong. <P>SOLUTION: The method is for manufacturing the transportation pallet 2 which has the bottom board 4, and the peripheral frame 6 raised from the vicinity of the periphery of the bottom board 4. A metal plate so as to form an installation recess 8 on the bottom board 4 is provided to form the bottom board 4. The metal plate 4 is attached to a first die 20 to form a first cavity 22 that is in contact with the metal plate 4. A reaction stock solution is poured into the first cavity 22 to carry out a reaction injection molding, after which the first die 20 is removed from the metal plate 4 to form the peripheral frame 6, which is integral to the metal plate 4 and is made of a reaction injection mold resin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a pallet for conveyance for conveying components such as a vehicle-mounted sheet.

  Wooden pallets, resin pallets, and metal pallets are known as pallets for conveying parts within or between factories. The wooden pallet has a problem that it may not be used in an environment where there is a risk of generating wood dust and the like and the generation of dust or dust is disliked.

  In this respect, the resin pallet is advantageous in that it is lightweight and does not generate wood chips. However, resin pallets generally tend to lack mechanical strength.

  In contrast, metal pallets have sufficient mechanical strength, but have the problem of being heavy. In addition, for example, a pallet for conveying a vehicle-mounted sheet or the like needs to form a peripheral frame part, but in order to make the part also made of metal, work such as bending or welding is required, The work is complicated. In addition, it is not preferable that all parts of the pallet are made of metal because the whole weight increases.

  Then, as shown in the following Patent Document 1, it has been proposed to reinforce a resin pallet with a square steel material.

However, in such a resin pallet, the bottom plate portion is made of resin, which is also undesirable from the viewpoint of mechanical strength and the desire to maintain flatness, and the bottom plate portion of the pallet should be made of a metal plate. There is a request. Conventionally, the bottom plate part is made of a metal plate, and the peripheral frame part is made of resin, making it difficult to produce a lightweight yet high-strength pallet with a simple method and high productivity. Met.
JP-A-10-114337

  The present invention has been made in view of such a situation, and the bottom plate part is made of a metal plate, and the peripheral frame part is made of a resin. An object of the present invention is to provide a method for manufacturing a pallet for transportation that can be easily produced with high productivity.

In order to achieve the above-mentioned object,
A bottom plate,
A peripheral pallet formed from the vicinity of the peripheral position of the bottom plate part so as to form an installation recess on the bottom plate part,
Preparing a flat metal plate that will form the bottom plate portion;
Combining a first mold with the metal plate to form a first cavity in contact with the metal plate;
The reaction stock solution is poured into the first cavity to perform reaction injection molding, the first mold is removed from the metal plate, and the peripheral frame made of reaction injection molding resin integrated with the metal plate is formed. And a process.

  According to the manufacturing method of the pallet for conveyance which concerns on this invention, after using the metal plate used as the baseplate part of a pallet as a part of metal mold | die and removing a metal mold | die, a metal plate becomes a baseplate part of a pallet. Then, the reaction injection molding resin is integrated with the metal plate after the mold is removed, and that portion becomes the peripheral frame. For this reason, in the method of the present invention, the bottom plate portion is made of a metal plate, and the peripheral frame portion is made of resin, so that a lightweight yet high-strength pallet can be manufactured very easily. it can.

Preferably, the method of the present invention comprises:
Combining a second mold on the opposite surface of the metal plate on which the peripheral frame is formed to form a second cavity that contacts the metal plate;
Performing a reaction injection molding by pouring a reaction stock solution into the second cavity, removing the second mold from the metal plate, and forming a leg portion made of a reaction injection molding resin integrated with the metal plate; And.

  There is a case where it is desired to integrate a resin leg portion on the back surface of the metal plate serving as the bottom plate. However, in the method of the present invention, this resin leg portion can be easily manufactured.

In the method of the present invention,
For the front and back surfaces of the metal plate, the first mold and the second mold are combined at the same time, and the first cavity and the second cavity are formed simultaneously.
In the metal plate, a cavity connecting through hole that communicates the first cavity and the second cavity is formed in advance,
The reaction stock solution is poured into one of the first cavity and the second cavity, filled with the reaction stock solution through the cavity communication through-hole to the other cavity, and subjected to reaction injection molding. The mold and the second mold may be removed from the metal plate, and the peripheral frame and the leg portion made of reaction injection molding resin integrated with the metal plate may be formed simultaneously.

  According to this method, the manufacturing process can be shortened as compared with the process of separately molding the peripheral frame and the leg portion. Moreover, since the reaction injection molded resin portions formed on the front and back surfaces of the metal plate are connected through the cavity connecting through holes formed in the metal plate, the degree of integration of the resin portion with the metal plate is improved.

In the method of the present invention,
In the first cavity formed by the first mold and the metal plate, a metal pipe is arranged in advance, and thereafter, a reaction stock solution is filled and reaction injection molding is performed,
A metal pipe may be integrated with a part of the peripheral frame.

  According to this method, the pallet for conveyance with which the metal pipe was integrated can be manufactured very easily. Further, since the metal pipe is integrated with the manufactured transport pallet, the mechanical strength is further improved.

  In the present invention, it is preferable that an anchor protrusion for improving the bonding strength with the reaction injection molding resin formed on the surface of the metal plate is mounted in advance. According to this method, the bonding strength between the metal plate and the resin is improved.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a front perspective view of a transport pallet obtained by a manufacturing method according to an embodiment of the present invention,
2 is a rear perspective view of the conveying pallet shown in FIG.
FIG. 3 is a cross-sectional view of a main part of a mold for manufacturing the pallet shown in FIGS. 1 and 2, and is a view showing a cross section corresponding to a portion along line III-III in FIG.
FIG. 4 is a cross-sectional view of a main part of the mold showing a continuation process of FIG. 3, and is a view showing a cross section corresponding to a portion along line IV-IV in FIG.
FIG. 5 is a view for explaining an anchor projection attached to a metal plate combined with a mold;
FIG. 6 is a sectional view of an essential part of a mold for manufacturing a pallet according to another embodiment of the present invention.

  As shown in FIG. 1, a sheet pallet 2 as a conveying pallet according to an embodiment of the present invention has a rectangular bottom plate portion 4. The peripheral frame 6 rises upward in a direction substantially perpendicular to the surface 4a of the bottom plate portion 4 from the vicinity of the four sides of the bottom plate portion 4 so as to form the installation recess 8 on the surface 4a of the bottom plate portion 4. Is formed. In the present embodiment, the peripheral frame 6 includes a total of four long side frames 6a and short side frames 6b. In the installation recess 8, for example, an automobile seat part is installed.

  In this embodiment, the four side frames 6a and 6b are formed continuously so as to surround the installation recess 8. However, it may be formed intermittently without being partly continuous due to interference with the load. The height from the upper surface of the bottom plate part 4 in the side frame 6 is the same in the four side frames 6a and 6b. Although the height of these side frames 6a and 6b is not particularly limited, it is preferably 5 to 100 mm when an in-vehicle seat is installed on the pallet 2. The widths of the side frames 6a and 6b are approximately the same as the heights of the side frames 6a and 6b. However, a wide portion 6c having an increased width may be formed in a part of the side frames 6a and 6b.

  The size of the bottom plate portion 4 is about 400 to 800 mm × 1000 to 1800 mm. Moreover, the thickness of the baseplate part 4 is about 2-10 mm. The bottom plate portion 4 is made of a metal plate such as stainless steel, aluminum, steel, zinc alloy, or titanium.

  A pair of long side frames 6a facing each other so as to be located on the long side of the rectangular bottom plate portion 4 are integrated with a metal pipe (hollow pipe) 10 having a circular cross section so that the upper half is exposed. It is. The metal pipe 10 is made of, for example, the same metal as the bottom plate portion 4.

  As shown in FIG. 2, legs 12 are attached to the back surface 4 b of the pallet 2. In this embodiment, the leg portions 12 are arranged in the longitudinal direction so as to connect two rows of linear leg portions 12a extending in parallel with the longitudinal direction X on the back surface 4b of the pallet 2 and both ends of the linear leg portions 12a. X and two rows of linear leg portions 12b extending in the perpendicular direction Y. The height and width of these linear legs 12a and 12b are approximately the same as the height and width of the side frames 6a and 6b formed on the surface 4a.

  In the present embodiment, the front and back surfaces of the bottom plate portion 4 made of a metal plate are exposed except for portions covered by the peripheral frame 6 and the leg portions 12. In this embodiment, the peripheral frame 6 and the leg 12 are integrally formed by reaction injection molding of a norbornene monomer. Polynorbornene resin formed integrally by reaction injection molding of norbornene monomer is excellent in mechanical strength and easy to mold, and is suitable as a molding material for pallets.

  In the present embodiment, the reaction injection molding is performed as follows, for example. That is, as shown in FIG. 3, the first mold 20 is combined with the surface 4 a of the metal plate that becomes the bottom plate portion 4. A cavity 22 for forming the peripheral frame 6 having the shape shown in FIG. 1 is formed in the first mold 20. The metal pipe 10 is disposed in the cavity 22 in advance. In order to inject a reaction stock solution (a mixed solution of reaction solution A and reaction solution B, which will be described later) into the cavity 22, an injection port 24 is formed in the first mold 20.

  A reaction solution A and a reaction solution B, which will be described later, are mixed and injected into the injection port 24 from a mixer, filled in a cavity, and reaction injection molding is performed. Depending on the type of catalyst, the reaction mixture may be formed by mixing the raw material mixture and the catalyst (ruthenium-based catalyst) with a mixer and filling the mixture into the cavity 22 from the injection port 24.

  The first mold 20 is not necessarily a high-rigid and expensive mold, and is not limited to a metal mold, and may be a resin mold or a simple mold. This is because reaction injection molding has a lower filling pressure and clamping pressure than ordinary injection molding.

  The reaction injection molding performed in this embodiment is reaction injection molding using a norbornene-based monomer, and the monomer used has a norbornene ring such as dicyclopentadiene, dihydrodicyclopentadiene, tetracyclododecene, tricyclopentadiene or the like. The catalyst used for the cycloolefin is a metathesis catalyst (a catalyst for performing a metathesis reaction) described later.

  Metathesis catalysts that can be used in reaction injection molding using norbornene monomers include norbornene monomers such as molybdate organic ammonium salts such as tungsten hexachloride, tridodecyl ammonium molybdate, and tri (tridecyl) ammonium molybdate. The catalyst is not particularly limited as long as it is a known metathesis catalyst as a bulk polymerization catalyst, but a molybdate organic ammonium salt is preferable.

  Examples of the activator (cocatalyst) include alkylaluminum halides such as ethylaluminum dichloride and diethylaluminum chloride, alkoxyalkylaluminum halides, and organic tin compounds.

  As a preparation for reaction injection molding, a reaction injection molding material mainly composed of a norbornene monomer, a metathesis catalyst and an activator is used as a reaction liquid A comprising a norbornene monomer and a metathesis catalyst, and the norbornene monomer and activator. The reaction liquid B is divided into two stable liquids and each is put in a separate tank.

  In such molding, a reinforcing polymer coating layer can be produced by previously installing a reinforcing material in a cavity of a mold, and supplying a reaction liquid therein to cause polymerization.

  Examples of the reinforcing material include glass fiber, aramid fiber, carbon fiber, ultra high molecular weight polyethylene fiber, metal fiber, polypropylene fiber, aluminum coated glass fiber, cotton, acrylic fiber, boron fiber, silicon carbide fiber, alumina fiber, and the like. be able to. These reinforcing materials can be used in various shapes such as those obtained by matting long fiber or chopped strands, those woven into a cloth, and those having a chopped shape. These reinforcing materials are preferably treated with a coupling agent such as a silane coupling material in order to improve the adhesion to the resin. The blending amount is not particularly limited, but is usually 10% by weight or more, preferably 20 to 60% by weight based on the total weight of the molded product.

  In addition, by blending various additives such as antioxidants, fillers, pigments, colorants, foaming agents, flame retardants, sliding imparting agents, elastomers, dicyclopentadiene thermal polymerization resins and hydrogenated products thereof, The properties of the resulting polymer can be modified.

  As the antioxidant, there are various antioxidants for plastics and rubbers such as phenol, phosphorus and amine. Examples of the filler include inorganic fillers such as milled glass, carbon black, talc, calcium carbonate, aluminum hydroxide, and mica. As the elastomer, natural rubber, polybutadiene, polyisoprene, styrene-butadiene copolymer (SBR), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), ethylene- Examples include propylene-diene terpolymer (EPDM), ethylene vinyl acetate copolymer (EVA), and hydrides thereof.

  To start reaction injection molding, liquid A and liquid B from the respective tanks are mixed and filled into the cavity as a reaction stock solution. The reaction stock solution filled in the cavity reaches the inside of the cavity. After the molding, if the first mold 20 is removed from the bottom plate part 4 used as a part of the mold, the bottom plate in which the peripheral frame 6 including the side frames 6a and 6b shown in FIG. 1 is integrally formed. A molded body of part 4 is obtained. The metal pipe 10 is also integrated with the peripheral frame 6.

  Next, in the present embodiment, as shown in FIG. 4, the peripheral frame 6 in which the metal pipe 10 is integrated is formed on the back surface 4 b of the bottom plate portion 4 formed of a metal plate formed on the front surface 4 a. 2 molds 30 are combined. The second mold 30 is formed with a cavity 32 for forming the leg portion 12 shown in FIG. The second mold 30 is formed with an inlet 34 for injecting a reaction stock solution into the cavity 32. The second mold 30 is made of the same material as that of the first mold 20. The reaction injection molding in the cavity 32 of the second mold 30 may be performed in the same manner as the cavity 22 of the first mold 20.

  Thereafter, if the second mold 30 is removed from the bottom plate part 4 used as a part of the mold, a molded body of the bottom plate part 4 in which the leg parts 12 shown in FIG. 2 are integrally formed is obtained. . As a result, a sheet pallet 2 shown in FIG. 1 is obtained in which the peripheral frame 6 is formed on the front surface 4a of the bottom plate portion 4 and the legs 12 are integrally formed on the back surface 4b.

  According to the manufacturing method of the sheet pallet 2 according to the present embodiment, the metal plate that becomes the bottom plate portion 4 of the pallet 2 is used as a part of the mold, and after the mold is taken out, the metal plate is the bottom plate of the pallet 2. It becomes part 4. Then, the reaction injection molding resin is integrated into the metal plate after the mold is taken out, and the portions become the peripheral frame 6 and the leg portion 12. For this reason, in the method of this embodiment, the bottom plate part 4 is made of a metal plate, and the peripheral frame part 6 and the leg part 12 are made of resin. Can be manufactured very easily.

The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.
For example, as shown in FIG. 5, screws 40 or screws as anchor protrusions are attached in advance to the front surface 4 a or the back surface 4 b of the bottom plate 4 combined with the mold 20 or 30 so as to form the cavity 22 or 32. You may do it. The anchor protrusion such as the screw 40 or the screw is integrated into the resin formed by reaction injection molding inside the cavity 22 or 32, and the bonding strength between the resin and the bottom plate portion 4 is improved.

  Moreover, in this invention, as shown in FIG. 6, you may assemble | attach the 1st metal mold | die 20a and the 2nd metal mold | die 30 at once with respect to both surfaces 4a and 4b of the baseplate part 4 comprised with a metal plate. However, in this embodiment, the injection port 22 is not formed in the first mold 20a, and the cavity is connected to the metal plate of the bottom plate portion 4 at the portion where the first cavity 22 and the second cavity 32 intersect. The through hole 4c is formed in advance. The cavity communication through holes 4c are preferably formed at a plurality of positions.

  By forming the cavity communication through hole 4c, the reaction stock solution filled from the injection port 32 of the second mold 30 reaches the first cavity 22 from the second cavity 32 through the through hole 4c, The inside of one cavity 22 is also filled. According to this method, the manufacturing process can be shortened compared to the process of separately molding the peripheral frame 6 and the leg 12. In addition, the reaction injection molding resin portions formed on the front and back surfaces of the bottom plate portion 4 made of a metal plate are connected through the cavity connection through-hole 4c formed in the metal plate, and thus made of the metal plate. The degree of integration of the peripheral frame (resin portion) 6 and the leg portion (resin portion) 12 with respect to the bottom plate portion 4 is improved.

  In the embodiment described above, the metal pipe 10 is integrated with the long side frame 6b. However, the present invention is not limited to this, and depending on the use of the pallet 2, the metal pipe 10 may be integrated with the long side frame. It is not necessary to integrate with 6b. In that case, the process of attaching a metal pipe to the inside of the first cavity in the mold becomes unnecessary. Other manufacturing processes are the same as those in the above-described embodiment, and have the same functions and effects.

FIG. 1 is a front-side perspective view of a conveying pallet obtained by a manufacturing method according to an embodiment of the present invention. 2 is a rear perspective view of the conveying pallet shown in FIG. FIG. 3 is a cross-sectional view of a main part of a mold for manufacturing the pallet shown in FIGS. 1 and 2, and is a view showing a cross section corresponding to a portion along line III-III in FIG. FIG. 4 is a cross-sectional view of the main part of the mold showing the continuation process of FIG. FIG. 5 is a view for explaining an anchor projection attached to a metal plate combined with a mold. FIG. 6 is a sectional view of an essential part of a mold for manufacturing a pallet according to another embodiment of the present invention.

Explanation of symbols

2 ... Sheet pallet (Pallet for conveyance)
DESCRIPTION OF SYMBOLS 4 ... Bottom plate part 4a ... Front surface 4b ... Back surface 4c ... Through hole for cavity connection 6 ... Peripheral frame 8 ... Recess for installation 10 ... Metal pipe 12 ... Leg part 20, 20a ... 1st metal mold 22 ... 1st cavity 30 ... Second mold 32 ... Second cavity 40 ... Screw (anchor projection)

Claims (5)

A bottom plate,
A peripheral pallet formed from the vicinity of the peripheral position of the bottom plate part so as to form an installation recess on the bottom plate part,
Preparing a flat metal plate that will form the bottom plate portion;
Combining a first mold with the metal plate to form a first cavity in contact with the metal plate;
The reaction stock solution is poured into the first cavity to perform reaction injection molding, the first mold is removed from the metal plate, and the peripheral frame made of reaction injection molding resin integrated with the metal plate is formed. And a method of manufacturing a pallet for conveyance having the steps. Combining a second mold on the opposite surface of the metal plate on which the peripheral frame is formed to form a second cavity that contacts the metal plate;
Performing a reaction injection molding by pouring a reaction stock solution into the second cavity, removing the second mold from the metal plate, and forming a leg portion made of a reaction injection molding resin integrated with the metal plate; The manufacturing method of the pallet for conveyance of Claim 1 which further has these. For the front and back surfaces of the metal plate, the first mold and the second mold are combined at the same time, and the first cavity and the second cavity are formed simultaneously.
In the metal plate, a cavity connecting through hole that communicates the first cavity and the second cavity is formed in advance,
The reaction stock solution is poured into one of the first cavity and the second cavity, filled with the reaction stock solution through the cavity communication through-hole to the other cavity, and subjected to reaction injection molding. The mold and the second mold are removed from the metal plate, and the peripheral frame and the leg portion made of reaction injection molding resin integrated with the metal plate are formed simultaneously. The manufacturing method of the pallet for conveyance as described. In the first cavity formed by the first mold and the metal plate, a metal pipe is arranged in advance, and thereafter, a reaction stock solution is filled and reaction injection molding is performed,
The method for manufacturing a transport pallet according to any one of claims 1 to 3, wherein a metal pipe is integrated with a part of the peripheral frame. 5. The transport pallet according to claim 1, wherein anchor projections for improving the bonding strength with the reaction injection molding resin formed on the surface of the metal plate are mounted in advance. Production method.

Images