JP5517241B2 - Pallet, pallet molding die and pallet molding method - Google Patents

Description

  The present invention uses a pallet that is a so-called single-sided, four-sided resin integral molded product in which only one surface in the thickness direction is used as a load placement surface and a fork can be inserted from four sides, and its manufacture The present invention relates to a pallet molding die and a pallet molding method.

  Conventional pallet forming molds for forming this type of pallet include an upper surface mold and a lower surface mold that are opened in the thickness direction of the pallet, and four slides in a direction perpendicular to the mold opening direction. A fork insertion hole in the pallet is formed by a prism-shaped forming part provided with a pair of slide molds and one pair in each of the four slide molds (see, for example, Patent Document 1).

Japanese Patent No. 3518623 (FIGS. 9, 10, and 15)

  However, in the pallet manufactured with the above-described conventional pallet molding mold, the corners of the rectangular cylindrical girder that communicates between the top deck board and the bottom bottom board are orthogonal parts of the prismatic molding parts. Therefore, the ridge line portion had a sharp right-angled shape (so-called pin angle shape). For this reason, the tip of the fork is caught in the corner of the girder at the time of conveyance work by a forklift, or the corner of the girder bites into the operator's hand when performing manual conveyance. I couldn't. Also, the corner of the spar is damaged due to the hook of the fork described above, or the pallet bends during use in an automatic warehouse, etc., and stress concentrates on the spar of the spar. Could occur. In the so-called two-body molding method in which the pallet is divided into two parts in the thickness direction and then joined together, chamfering can be performed on the problem part in the girder, but it is manufactured compared to the integral molding method. There is a problem that costs are high.

  The present invention has been made in view of the above circumstances. A pallet capable of efficiently performing a transport operation and having excellent strength, and a pallet molding die and a pallet for manufacturing such a pallet are provided. The object is to provide a molding method.

In order to achieve the above object, the pallet according to the invention of claim 1 is arranged such that square cylindrical girders are arranged in three rows and three columns on the lower surface of a square deck board on which luggage can be placed. A pallet of resin-integrated molded products in which a bridge-shaped bottom board is formed between the lower ends of the girder part, and a deck-shaped bottom board is formed, and the deck board and the bottom board form a crosspiece structure when viewed from above and below. In addition, the corners of the four corners of each girder are chamfered to form a vertically chamfered surface, and the width of each bridging part is made smaller than the width of the girder part so that it is vertically elongated between adjacent bridging parts. Extending the chamfered surface, forming laterally chamfered surfaces that descend from the center of the width direction at both ends in the width direction of the bridge portion , and at least of the bridge portion extending in all directions from the centroid of the centroid of the deck board It is characterized by a part of the deck board covered from directly above.

  In the pallet molding die according to the invention of claim 2, the rectangular cylindrical girder portions are arranged in three rows and three columns on the lower surface of the square deck board on which the load can be placed, and the lower end portions of the adjacent girder portions are adjacent to each other. A bridge-shaped bottom board is formed between the bridges, and the bottom of the rice pad is formed. The deck board and the bottom board have a cross structure when viewed from above and below, and the corners of the four corners of each girder are chamfered. A pallet molding die for forming a pallet of a resin integrated molded product in which a longitudinally chamfered surface is formed and a longitudinally chamfered surface is extended to between adjacent cross-linked portions. And an upper surface mold and a lower surface mold that can be opened in the thickness direction of the pallet, and four slide molds that move linearly in a direction orthogonal to the mold opening direction of the upper surface mold and the lower surface mold. The two slide molds have the same structure and are shifted by 90 degrees. Both are provided with a long rectangular column-shaped molded part and a long rectangular column-shaped molded part protruding from the side molded part for molding the side surface of the pallet to form a fork insertion hole between the girder parts. The portion extends to a position in front of the fork insertion hole on the side that is orthogonal to the fork insertion hole that is molded and away from the side molding portion, while the short columnar molded portion is orthogonal to the fork insertion hole that it molds and The upper surface mold has a flat deck surface formed flat surface that abuts the slide mold group in the mold opening direction with respect to the lower surface mold, extending to a position near the fork insertion hole on the side closer to the side molded portion. The bottom forming mold has a flat bottom plate forming flat surface that comes into surface contact with the slide mold group in the mold opening direction with the top forming mold. There is a beam for molding the bottom plate The groove is formed as a depression, protrudes from the lower surface mold toward the upper surface mold, and is provided with four pairs of plate-like chamfered molding protrusions sandwiching each of the long prismatic molded portions in the width direction. It is characterized in that a longitudinally long chamfered surface for forming a vertically elongated chamfered surface is formed by chamfering both side edges of the preformed protruding piece.

  The invention according to claim 3 is the pallet molding die according to claim 2, wherein the pallet is formed with laterally chamfered surfaces that descend at the both ends in the width direction of the bridging portion as it goes away from the center in the width direction, The bottom surface mold is provided with a portion corresponding to the laterally long chamfered surface of the bridge portion as a pair of bridge side inclined surfaces inclined from the bottom plate forming flat surface, and a crosspiece is formed on each of the bridge side inclined surfaces. For the main body of the long rectangular columnar molded part and the short rectangular columnar molded part, the front corners on the lower surface mold side of the long rectangular columnar molded part and the short rectangular columnar molded part are formed. The movable block is composed of a separate part, and the movable block is engaged with the main body in a direction that crosses the linear movement direction of the slide mold obliquely and is in contact with and away from the lower surface mold, and is a slide mold. At the rear end position of the movable range when the is closed The movable block is configured such that a part protrudes from the main body part toward the lower surface mold side, and is arranged at the front end position of the movable range when the slide mold is opened and is separated from the lower surface mold part from the main body part. Is formed with a first abutting inclined surface that abuts the bridging side inclined surface in a portion protruding from the main body portion toward the lower surface mold when the slide mold is closed, and is cam-engaged with the lower surface mold. And four pairs of opening and closing arms facing each other in the direction orthogonal to the facing direction of the pair of chamfered projecting pieces, and a second contact that makes a surface contact with the bridge side inclined surface at the end of each opening and closing arm. An inclined surface is formed, and the pair of opening and closing arms approach each other with the upper surface molding die and the lower surface molding die opened, while being separated from each other with the upper surface molding die and the lower surface molding die closed, and the second contact inclination The surface is configured to abut the bridge side inclined surface to form a long prism Characterized in the proximal end portion of the parts and short prismatic shaped unit was formed a third contact inclined surfaces which abut crosslinking side inclined surface and the surface.

  The pallet manufacturing method according to the invention of claim 4 is characterized in that the pallet is manufactured using the pallet forming mold according to claim 2 or 3.

[Invention of Claim 1]
In the pallet according to the first aspect, the width of each bridging portion is made smaller than the width of the girder portion, so that the vertically long chamfered surface of the girder portion can be extended to between the adjacent bridging portions. As a result, a molding surface for a vertically chamfered chamfer is provided on the protruding portion of the bottom surface molding die that molds the bottom plate of the pallet molding die, so that the girder inside the pallet can be formed even if it is a resin-integrated product pallet. It becomes possible to form a longitudinally chamfered surface at the corner of the part. That is, according to the pallet of the present invention, the fork is caught in the girder part and the hand part is prevented from biting during hand conveyance, the efficiency of the conveyance work is improved, and the corner part of the girder part is also damaged. Prevents and improves strength. Further, since the horizontally long chamfered surfaces are formed at both ends in the width direction of the bridging portion, it is possible to prevent the fork from being caught in the bridging portion. Furthermore, since at least a part of the bridging portion that extends in all directions from the centroid of the centroid of the deck board is covered with the deck board from directly above , the strength can be increased compared to the other parts.

[Inventions of Claims 2 and 4]
The pallet molding die according to claims 2 and 4 comprises an upper surface molding die, a lower surface molding die, and four slide dies, and a fork insertion hole is formed by a long rectangular columnar molding part and a short rectangular columnar molding part provided in each slide mold. Is formed. The lower surface mold is provided with four pairs of plate-like chamfering protrusions, and the longitudinally chamfering surfaces on both side edges of each of the chamfering protrusions are used to form a girder at an orthogonal portion between the fork insertion holes. A vertically long chamfer is formed at the corner. That is, if the pallet formed by the pallet forming mold according to claims 2 and 4 is used, it is possible to prevent the fork from being caught in the girder part and to bite the girder part into the hand at the time of hand conveyance, so that the conveyance work can be performed efficiently. In addition, it is possible to prevent breakage at the corners of the spar and improve the strength.

[Invention of claim 3]
According to the pallet molding die of claim 3, even if the pallet is a resin-integrated product, the laterally chamfered chamfered surface can be formed on both ends of the bridge portion in the width direction. Specifically, according to the pallet molding die of claim 3, the pallet of the bridge portion is formed by the third abutting inclined surface formed at the base end portion of the long prismatic molded portion and the short prismatic molded portion. A laterally long chamfered surface located on the outer surface is formed. Moreover, the corner | angular part of each front-end | tip part of a long prismatic molded part and a short prismatic molded part is comprised by the movable block of another components, and the 1st contact | abutting inclined surface is formed in the movable block. Then, in the process of closing the slide mold, the movable block moves to the rear end position of the movable range with respect to the main body portion of the long prismatic molded portion and the short prismatic molded portion, and the first contact inclined surface becomes the bridging side inclined surface. And a part of the horizontally long chamfered surface group disposed inside the pallet is formed. Further, the lower surface mold is provided with a plurality of pairs of opening / closing arms in a cam-engaged state, and a second contact inclined surface is formed on the opening / closing arms. The pair of opening / closing arms are separated from each other in the process of mold closing, and the second contact inclined surface provided at the end of each opening / closing arm is in surface contact with the bridge side inclined surface, and is disposed inside the pallet. The remaining horizontally long chamfered surface group is formed.

(A) Side view of pallet according to one embodiment of the present invention, (B) Side sectional view of pallet Pallet top view Top view of the pallet without the bottom Bottom view of pallet Bottom view of the pallet without the deck board Side cross-sectional view of the pallet mold Slide cross section Side cross-sectional view during opening and closing of pallet forming mold Side cross-sectional view with pallet mold closed A side sectional view enlarging a part of the slide mold

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. As shown in FIG. 1 (A), the pallet 10 of this embodiment has a structure in which a deck board 11 and a bottom board 16 are connected by a plurality of girders 15. 2 shows a state in which the deck board 11 is viewed from above, and FIG. 3 shows a state in which only the deck board 11 is viewed from above without the bottom board 16. FIG. 4 shows a state in which the bottom board 16 is viewed from below, and FIG. 5 shows a state in which only the bottom board 16 is viewed from below without the deck board 11.

  As shown in FIGS. 2 and 3, the deck board 11 has a square planar shape, and the outer edge is provided with an outer edge band plate part 12 having a width of 1/20 or less of the length of one side of the deck board 11, The inner side of the outer edge band plate portion 12 has a crosspiece structure. Each girder 15 has a structure in which reinforcing walls 15B are provided at both upper and lower ends in a rectangular tube wall 15A having a substantially square planar shape. In addition, nine pallets 15 are provided for the entire pallet 10 and arranged in three rows and three columns, and are arranged at the four corners of the deck board 11, the central portion of each side, and the centroid. And between these girder parts 15 and 15 is a fork insertion hole 18, and the fork insertion hole 18 penetrates the pallet 10 vertically and horizontally.

  The deck board 11 is formed with a belt-like reinforcing grid portion 13 so as to communicate between the adjacent girder portions 15 and 15 in the vertical direction or the horizontal direction. It has a shape. Further, the rectangular area 11 </ b> A surrounded by the reinforcing grid portion 13 on all four sides of the deck board 11 is closed by the lightweight grid portion 14. The lightening lattice portion 14 has a lattice shape having a plurality of square cells. On the other hand, the reinforced grid portion 13 has a relatively fine rectangular grid in which a plurality of the grids of the lightened grid section 14 are equivalent, and has a relatively high strength.

  As shown in FIG. 5, the bottom board 16 is comprised by the bridge | bridging part 17 passed between the lower end parts of the adjacent girder parts 15 and 15, and the whole becomes the shape of a "field". Unlike the quadrangular area 11A of the deck board 11, the quadrangular area 16A surrounded by the bridging portion 17 in the bottom board 16 is open as a whole. For this reason, the pallet 10 can be used only on one side with the deck board 11 arranged on the upper side, but a hand forklift can be used.

  Each bridge portion 17 extending in all directions from the centroid of the bottom plate 16 is constituted by three bridge portion constituting beams 17K extending in parallel. On the other hand, the bridging portion 17 arranged at the outer edge portion of the bottom board 16 in the bridging portion 17 group has a lattice shape with relatively fine rectangular eyes as in the reinforced grid portion 13 of the deck board 11. ing. All the bridging portions 17 are entirely covered with the reinforcing lattice portions 13 of the deck board 11 from directly above. As shown in FIG. 4, when the pallet 10 is viewed from below, the reinforcing grid portion 13 of the deck board 11 can be visually recognized from between the bridge portion constituting beams 17K and 17K.

  Now, in the lower part of the deck board 11, as shown in FIG. 5, the corners of the four corners of each girder 15 are chamfered to form vertically chamfered surfaces 15S and 15R. Specifically, the vertically chamfered surface 15S facing the quadrangular region 16A in the girder portion 15 has a shape in which the corner portion of the girder portion 15 is chamfered by 45 degrees, and the other vertically long chamfered surface 15R is the girder portion 15. It is the shape which rounded off the corner | angular part. In the group of vertically chamfered chamfered surfaces 15R, the vertically chamfered surfaces 15R at the four corners of the base 16 have a smaller chamfered radius of curvature than the other vertically chamfered surfaces 15R. In the present embodiment, the chamfer angle of the chamfered portion of the beam portion 15 is 45 degrees as described above, but the chamfer angle is not limited to 45 degrees.

  The bridging portion 17 is narrower than the girder portion 15 so as to avoid the vertically long chamfered surface 15S facing the quadrangular region 16A. And the bridge | bridging part 17 extended to the four directions from the centroid of the base 16 is connected with the part except the vertically long chamfering surfaces 15S and 15S of both ends among each side surfaces of the girder part 15. FIG. In addition, the bridging portion 17 disposed on the outer edge portion of the bottom plate 16 is connected to a portion of each side of the girder portion 15 excluding the vertically chamfered surface 15S on the quadrangular region 16A side. And the outer surface of the girder 15 are flush with each other.

  As shown in FIG. 1 (B), laterally long chamfered surfaces 17S and 17S are formed at both ends in the width direction of the bridging portion 17 so as to fall away from the center in the width direction. Further, at the opening edge of the side opening of the fork insertion hole 18, an upper laterally chamfered surface 11S is formed in a portion of the deck board 11 facing the laterally chamfered surface 17S from above.

  The description regarding the structure of the pallet 10 of this embodiment is above. Next, a pallet forming mold 20 for forming the pallet 10 will be described. As shown in FIG. 6, the pallet molding die 20 includes an upper mold 21 and a lower mold 30 that can be opened in the thickness direction of the pallet 10, and mold opening directions of the upper mold 21 and the lower mold 30. It comprises four slide molds 40 (see FIG. 7) that move linearly in orthogonal directions.

  As shown in FIG. 8, the upper surface molding die 21 is provided with a flat deck board molding flat surface 21 </ b> A that comes into surface contact with the slide mold 40 group in the mold opening direction with the lower surface molding die 30. In 21A, a beam forming groove 21M for forming a beam of the deck board 11 is recessed.

  As shown in FIG. 6, the lower surface mold 30 has a main mold 38 and an auxiliary mold 39 disposed on the opposite side of the upper surface mold 21 with the main mold 38 interposed therebetween. Further, the main mold 38 is provided with a flat bottom plate forming flat surface 30A that comes into surface contact with the slide mold 40 group in the mold opening direction with respect to the upper surface forming die 21. In the character-shaped region, a bar forming groove 30M for forming the bar of the bottom board 16 is formed in a recessed manner. Further, the lower surface mold 30 has a pair of bridge side inclined surfaces in which a portion corresponding to the horizontally long chamfered surface 17S of the bridge portion 17 is inclined from the bottom plate forming flat surface 30A and gradually separated from the upper surface mold 21. It is 32S. Further, a cross-section forming groove 30M for forming a cross-section of the bottom board 16 is also recessed in each bridge side inclined surface 32S. Note that the main molding die 38 of the upper surface molding die 21 and the lower surface molding die 30 has a girder molding projection 20K (see FIG. 20) for molding the inner side surface of the rectangular tube wall 15A and the reinforcing wall 15B in the girder portion 15 of the pallet 10. 7) are projectingly formed.

  The main molding die 38 of the lower surface molding die 30 is provided with a pair of plate-like chamfering projections 31, 31 for each rectangular area 16 </ b> A (see FIG. 5) of the pallet 10. Each of the chamfering protrusions 31 protrudes from the main forming die 38 toward the upper surface forming die 21, and the tips of the chamfering forming protrusions 31, 31 are in a state where the upper surface forming die 21 and the lower surface forming die 30 are closed. The surface comes into contact with the deck board forming flat surface 21A of the upper surface forming die 21 (see FIG. 8). Also, each chamfered protruding piece 31 is chamfered at 45 degrees on both sides to form a pair of vertically elongated chamfered surfaces 31S, 31S. A chamfered surface 15S (see FIG. 5) is formed. In the present embodiment, the chamfering angle of both side edges of the chamfered protruding piece 31 is 45 degrees in accordance with the chamfering angle of the girder part 15, but the chamfering angle of the girder part 15 is 45 degrees. The chamfering angle of the chamfering shaped projecting piece 31 is not limited to 45 degrees, as is not limited to the degree.

  A pair of cam through holes 30 </ b> W and 30 </ b> W are formed through the main mold 38 of the lower surface mold 30 for each square area 16 </ b> A of the pallet 10. The pair of cam through holes 30W and 30W are arranged side by side in a direction orthogonal to the facing direction of the chamfering molding protrusions 31 and 31, and the upper mold from the back side of the main mold 38 on the auxiliary mold 39 side. It inclines so that it may approach each other toward the front side surface of 21 side. A pair of opening / closing arms 60, 60 are inserted into the pair of cam through holes 30W, 30W. The pair of opening and closing arms 60, 60 are not shown in the figure when viewed from the facing direction, but are formed in a plate shape having substantially the same width as the chamfered protruding protrusion 31, and when viewed from the direction orthogonal to the facing direction, FIG. As shown in FIG. 4, the shape is such that the auxiliary molds 39 approach each other toward the upper surface mold 21 side, and the distal end portions are bent toward the side away from each other.

  The front end surface of the open / close arm 60 forms a flat surface that can come into surface contact with the side surface of the slide mold 40 facing the lower surface mold 30 side. Further, the surface facing the auxiliary mold 39 side of the side protruding portion at the tip of the opening / closing arm 60 forms the second contact inclined surface 61S according to the present invention, and is inclined so as to be separated from the auxiliary mold 39 toward the tip. ing. Further, the base end portions of the open / close arms 60 and 60 are engaged with the auxiliary mold 39 so as to be slidable in the opposing direction of the open / close arms 60 and 60. As shown in FIG. 6, in a state where the lower surface mold 30 and the upper surface mold 21 are opened, the main mold 38 and the auxiliary mold 39 approach each other so that the open / close arms 60 and 60 approach each other. On the other hand, when the lower surface mold 30 and the upper surface mold 21 are in the closed state, the main mold 38 and the auxiliary mold 39 are separated from each other as shown in FIG. The second contact inclined surface 61S of the arm 60 is in surface contact with the bridging side inclined surface 32S of the lower surface mold 30.

  As shown in FIG. 7, the four slide dies 40 have the same structure and are shifted by 90 degrees. In addition, each slide mold 40 is used to mold the side surface molding member 41 having the side surface molding surface 41A for molding the side surface of the pallet molding die 20, and the fork insertion hole 18 (see FIG. 1) of the pallet 10. A long prismatic molded part 42 and a short prismatic molded part 43 protruding from the side molding member 41 are provided. The long columnar molded portion 42 extends to a position in front of the fork insertion hole 18 on the side that is orthogonal to the fork insertion hole 18 to be molded and is away from the side surface molding member 41. On the other hand, the short columnar molded portion 43 extends to a position in front of the fork insertion hole 18 on the side that is orthogonal to the fork insertion hole 18 to be molded and is closer to the side molding member 41. Thereby, in the state where the slide mold 40 is closed, the respective front end surfaces of the other long rectangular columnar molded part 42 and the short rectangular columnar molded part 43 are opposed to both side surfaces of the long rectangular columnar molded part 42. Then, between the both side surfaces of the long prismatic molding part 42 and the respective front end surfaces of the other long prismatic molding part 42 and the short prismatic molding part 43, the chamfering projection pieces 31 of the lower surface molding die 30, 31 is sandwiched.

  As shown in FIG. 10, the corners on the lower surface molding die 30 side at the respective front end portions of the long prismatic molded portion 42 and the short prismatic molded portion 43 are formed by the long prismatic molded portion 42 and the short prismatic molded portion 43. It is composed of a movable block 50 which is a separate part from the main body portions 42H and 43H. Each movable block 50 is engaged with the main body portions 42H and 43H so as to be linearly movable so as to be obliquely intersected with the linear movement direction of the slide mold 40 and in contact with and away from the lower surface molding die 30, and the slide mold 40 is closed. Is disposed at the rear end position of the movable range with respect to the main body portions 42H and 43H, and a part of the movable portion protrudes from the main body portions 42H and 43H to the lower surface mold 30 side. It arrange | positions at the front-end position, and it leaves | separates from the lower surface shaping | molding die 30 from the main-body parts 42H and 43H. In each movable block 50, a first contact inclined surface 51S according to the present invention is formed in a portion protruding from the main body portions 42H and 43H toward the lower surface mold 30 when the slide mold 40 is closed. . More specifically, the linear movement direction of the slide mold 40 from the position closer to the upper surface mold 21 out of the distal end surfaces of the entire long rectangular columnar molded part 42 and the short rectangular columnar molded part 43 is provided at the distal ends of the main body parts 42H and 43H. A recess 59 having an inclined surface 59A inclined to the lower surface mold 30 side at an angle of 20 to 30 degrees and a vertical surface 59B extending straight from the inclined surface 59A toward the lower surface mold 30 side is formed. In the depressed portion 59, a guide shaft 59C extending from the vertical surface 59B and extending along the inclined surface 59A is provided.

  The movable block 50 is engaged with the guide shaft 59C so as to be able to move linearly, and a rear end surface 51B that can be brought into surface contact with the vertical surface 59B of the depressed portion 59, and the vertical surface 59B and the rear end surface 51B are in surface contact with each other. 9 (see FIG. 9), it has a tip surface 51T that is flush with the tip surfaces 42P and 43P of the main body portions 42H and 43H, and an inclined surface 51A that is parallel to the inclined surface 59A of the depressed portion 59. Further, the side surface 50Z on the lower surface molding die 30 side of the movable block 50 protrudes obliquely toward the lower surface molding die 30 side from the position near the front end surface 51T toward the front end surface 51T, and the inclined surface is the first contact according to the present invention. It is a tangentially inclined surface 51S. Further, the movable block 50 is urged by an urging means (not shown) and normally protrudes forward from the front end surfaces of the main body portions 42H and 43H, and the first contact inclined surface 51S is the main body portion. 42H and 43H are arranged on the upper surface mold 21 side from the side surface (reference numeral 30Z in FIG. 10) on the lower surface mold 30 side. In the process of closing the slide mold 40, the front end surface 51T of the movable block 50 is pressed against the chamfered projecting protrusion 31, and the movable block 50 moves rearward relative to the main body portions 42H and 43H. The first contact inclined surface 51S of the block 50 protrudes from the side surfaces of the main body portions 42H and 43H toward the lower surface mold 30 and comes into surface contact with the bridging side inclined surface 32S of the lower surface mold 30 (see FIG. 9).

  As shown in FIG. 6, third contact inclined surfaces 40 </ b> S and 40 </ b> S are formed on the bottom surface mold 30 side at the base end portions of the long prismatic molded portion 42 and the short prismatic molded portion 43 of the slide mold 40. ing. When the slide mold 40 is closed, each third contact inclined surface 40S comes into surface contact with the bridging side inclined surface 32S of the lower surface mold 30 (see FIG. 9). In addition, as shown in FIG. 8, fourth contact inclined surfaces 40 </ b> X and 40 </ b> X are formed on the upper surface mold 21 side at the base end portions of the long prismatic molded portion 42 and the short prismatic molded portion 43 of the slide mold 40. Is formed. When the slide mold 40 is closed, the upper laterally long chamfered surface 11S is formed by the fourth contact inclined surfaces 40X.

  This completes the description of the configuration of the pallet molding die 20 of the present embodiment. Next, a method for manufacturing the pallet 10 using the pallet forming mold 20 will be described. As shown in FIG. 6, the space between the upper surface mold 21 and the lower surface mold 30 is first closed from the state where the pallet mold 20 is opened. At this time, the main mold 38 and the auxiliary mold 39 of the lower surface mold 30 are relatively separated from each other to operate the open / close arms 60, 60, and as shown in FIG. 61S comes into surface contact with the bridging side inclined surface 32S of the lower surface mold 30 and closes the groove opening of the rail forming groove 30M. In addition, each chamfering projecting piece 31 of the lower surface mold 30 is abutted against the upper surface mold 21. Further, the not-shown girder molding protrusions 20K (see FIG. 7) of the upper surface molding die 21 and the lower surface molding die 30 are combined with each other.

  Next, the four slide molds 40 are moved forward, and the long prismatic molding part 42 and the short prismatic molding part 43 are inserted between the upper mold 21 and the lower mold 30. Then, the movable blocks 50, 50 at the tips of the long prismatic molded portion 42 and the short prismatic molded portion 43 come into contact with the chamfered molded protrusions 31, 31, so that the long prismatic molded portion 42 and the short prismatic molded portion 43 The movable blocks 50, 50 move rearward and toward the lower surface mold 30 with respect to the main body portions 42H, 43H, and the first contact inclined surface 51S of the movable block 50 faces the bridge side inclined surface 32S of the lower surface mold 30. It abuts and closes the groove opening of the crosspiece forming groove 30M. Further, at the base end portions of the long rectangular columnar molded portion 42 and the short rectangular columnar molded portion 43, the third contact inclined surface 40S comes into surface contact with the bridging side inclined surface 32S of the lower surface mold 30, and the beam forming groove 30M. Block the groove opening. Further, the surface contact between the deck board forming flat surface 21A of the upper surface forming mold 21 and the side surface of the slide mold 40 on the upper surface forming mold 21 side, and the bottom surface of the bottom board forming flat surface 30A of the lower surface forming mold 30 and the lower surface of the slide mold 40. The groove opening of the crosspiece forming groove 30M is also closed by the surface contact with the side surface on the mold 30 side. Further, as shown in FIG. 7, the beam forming protrusions 20 </ b> K of the upper surface forming die 21 and the lower surface forming die 30 have a pair of long columnar forming portions 42 and a pair of short angles via a rectangular tube-shaped gap. It will be in the state surrounded by the column-shaped shaping | molding part 43 and the vertically long chamfering shaping | molding surface 31S of the chamfering shaping | molding protrusion 31. FIG.

  When the pallet molding die 20 is in the closed state as described above, the molten resin is filled into the gaps around the beam forming grooves 30M and the girder molding projections 20K. Then, an operation opposite to the mold closing operation in which the molten resin is solidified is performed to open the pallet molding die 20 and take out the pallet 10 from the pallet molding die 20.

  As described above, in the pallet 10 of the present embodiment, the width of each bridging portion 17 is made smaller than the width of the girder portion 15 so that the longitudinally chamfered surfaces 15S of the corner portions of the girder portion 15 are adjacent and orthogonal to each other. It can be extended to between 17,17. Thus, a vertically long chamfered molding surface 31S for a vertically long chamfered surface is provided on the protruding portion (chamfered molded protrusion 31) of the lower surface mold 30 for molding the bottom plate 16 of the pallet 10 in the pallet molding die 20. Even if the pallet 10 is a resin-integrated product, it is possible to form the vertically chamfered surface 15S at the corners of the girder 15 inside the pallet 10. That is, according to the pallet 10 formed by the pallet forming mold 20 of the present embodiment, the fork is caught in the girder 15 and the girder 15 is not caught in the hand at the time of hand conveyance, and the efficiency of the conveyance work is reduced. While improving, the breakage | damage in the corner | angular part of a girder part is also prevented and intensity | strength improves. Further, since the horizontally long chamfered surfaces 17S are formed at both ends in the width direction of the bridging portion 17, it is possible to prevent the fork from being caught in the bridging portion 17 as well. Furthermore, since the deck board 11 is not provided with a hole for inserting a mold for forming a horizontally chamfered surface and the entire horizontally chamfered surface 17S is covered with the deck board 11, the strength is higher than that of the other. Up is also planned.

  In addition, this invention is not limited to the said embodiment, In the range which does not deviate from a summary other than the above, it can change and implement variously.

DESCRIPTION OF SYMBOLS 10 Pallet 11 Deck board 11S Upper horizontal chamfer 15 Girder part 15S Vertical chamfer 16 Bottom board 17 Bridging part 17S Horizontal chamfer 18 Fork insertion hole 20 Pallet molding die 21 Upper surface mold 21A Deck disk molding flat surface 21M Bar Forming groove 30 Lower surface molding die 30A Bottom plate molding flat surface 31 Chamfering molding protrusion 31S Longitudinal chamfering molding surface 32S Bridge side inclined surface 40 Slide mold 40S Third contact inclined surface 41 Side surface forming member 42 Long rectangular columnar molding portion 42H , 43H body part 43 short columnar shaped part 50 movable block 51S first contact inclined surface 60 opening / closing arm 61S second contact inclined surface

Claims (4)

A rectangular cylindrical girder is arranged in three rows and three columns on the lower surface of a rectangular deck board on which luggage can be placed, and a bridge portion is interposed between the lower ends of the adjacent girder portions. In the pallet of resin-integrated molded product, in which a character-shaped bottom board is configured, and the deck board and the bottom board have a crosspiece structure as viewed from above and below,
The corners of the four corners of each girder are chamfered to form a vertically chamfered chamfer, and the width of each bridging portion is made smaller than the width of the girder so that adjacent bridging portions are adjacent to each other. Extend the longitudinal chamfer until
At both ends of the bridge portion in the width direction, a laterally chamfered surface that is lowered as it is away from the center in the width direction is formed, and at least one of the bridge portions extending in all directions from the beam portion of the centroid of the deck board. A pallet characterized in that the deck board covers the part from directly above. A rectangular cylindrical girder is arranged in three rows and three columns on the lower surface of a rectangular deck board on which luggage can be placed, and a bridge portion is interposed between the lower ends of the adjacent girder portions. The deck board and the bottom board form a crosspiece structure when viewed from above and below, and the four corners of each girder are chamfered to form a vertically long chamfered surface. And a pallet molding die for molding a pallet of a resin-integrated molded product in which the vertically chamfered surface is extended between the cross-linked portions that are orthogonal to each other,
An upper surface mold and a lower surface mold that can be opened in the thickness direction of the pallet; and four slide molds that linearly move in a direction orthogonal to the mold opening direction of the upper surface mold and the lower surface mold;
The four slide molds are arranged to be shifted by 90 degrees with the same structure, and to form a fork insertion hole between the girder parts from a side molding part for molding the side surface of the pallet. The long prismatic molded portion and the short prismatic molded portion are formed to protrude, and the long prismatic molded portion is perpendicular to the fork insertion hole formed by the long prismatic molded portion and away from the side molded portion. The short prismatic molded part extends to a position before the fork insertion hole on the side that is perpendicular to the fork insertion hole that is molded and is closer to the side molding part.
The upper surface molding die has a flat deck board molding flat surface that comes into surface contact with the slide mold group in the mold opening direction with the lower surface molding mold, and a rail formation for molding the deck board rail there A ditch is formed,
The lower surface molding die has a flat bottom plate molding flat surface that comes into surface contact with the slide mold group in the mold opening direction with respect to the upper surface molding die, and there is a beam forming groove for forming the beam of the bottom plate there. A depression formed,
Four pairs of plate-like chamfering projections projecting from the lower surface molding die toward the upper surface molding die and sandwiching each of the long prismatic molding parts in the width direction are provided, and each of these chamfering molding projections is provided. A pallet molding die characterized in that a longitudinally chamfered molding surface for forming the longitudinally chamfered surface is formed by chamfering both side edges. The pallet is formed at both ends in the width direction of the bridging portion with a horizontally chamfered surface that is lowered as it is away from the center in the width direction,
The lower surface molding die is provided with a portion corresponding to the laterally long chamfered surface of the bridging portion as a pair of bridging side inclined surfaces inclined from the bottom plate forming flat surface. A beam forming groove for molding the beam is formed as a depression,
The tip corners on the bottom mold side of the long prismatic molded part and the short prismatic molded part are composed of movable blocks that are separate parts from the main body part of the long prismatic molded part and the short prismatic molded part. The movable block is engaged with the main body portion so as to be capable of linear movement in a direction obliquely intersecting the linear movement direction of the slide mold and in contact with and separating from the lower surface mold, and the slide mold is closed. Is disposed at the rear end position of the movable range with respect to the main body portion, and a part protrudes from the main body portion toward the lower surface mold, while the slide die is opened at the front end position of the movable range. The movable block is arranged so as to be separated from the lower surface molding die from the main body portion, and the bridging side of the movable block protrudes from the main body portion toward the lower surface molding die side when the slide die is closed. Inclined surface and surface The first contact inclined surfaces in contact is formed,
Four pairs of opening / closing arms that are cam-engaged with the lower surface mold and are opposed to each other in a direction orthogonal to the facing direction of the pair of chamfering protrusions are provided at the bridging side at the ends of the opening / closing arms. Forming a second abutting inclined surface that abuts with the portion inclined surface, and the pair of opening and closing arms approach each other while the upper surface molding die and the lower surface molding die are open, while the upper surface molding die and the lower surface The second mold contact inclined surface is configured to be in surface contact with the bridging side inclined surface and spaced apart from each other in a closed state of the mold.
3. The pallet molding according to claim 2, wherein a third contact inclined surface that is in surface contact with the bridge side inclined surface is formed at a base end portion of the long prismatic molded portion and the short prismatic molded portion. Mold.   A pallet manufacturing method, wherein the pallet is manufactured using the pallet forming mold according to claim 2.

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