JP2996218B2 - Plastic pallets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pallet made of synthetic resin which can be suitably used for continuously transporting various articles.

[0002]

2. Description of the Related Art A synthetic resin pallet provided with a front surface and a back surface provided with a fork insertion hole is conventionally known. However, in the conventional synthetic resin pallet, a hand lifter fork is inserted into the insertion hole. The rib structure may be such that the tip of the fork or the wheel attached to the fork collides when it is put in or taken out, or may be provided with an inclined rib for guiding the fork tip or the wheel of the hand lifter. Some are being developed. However, the pallet provided with the inclined ribs has a structure in which the ribs constituting the surface portion thereof are aligned in one direction, and the inclined ribs are provided only by the two dies of the fixed mold and the movable mold. Was something.

However, such a pallet has a disadvantage that the strength of the pallet cannot be increased. Especially when the forklift is incomplete,
That is, the fork is often used in a state of being inserted shallowly without being inserted deeply into the fork insertion hole, and in such a case, there is a risk of breakage if the strength of the end of the pallet is not large.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a fork,
In particular, an object of the present invention is to provide a synthetic resin pallet in which a fork of a hand lifter can be easily taken in and out, and the pallet is not easily damaged by taking in and out of the fork.

[0005]

SUMMARY OF THE INVENTION The present invention has a front surface portion and a back surface portion, and the front surface portion and the back surface portion have a cylindrical girder at the corner connecting the corner portions of the front surface portion and the back surface. A fork insertion hole is connected by an intermediate tubular girder connecting the intermediate portions around the back surface portion and a central tubular girder connecting the front surface portion and the central portion of the back surface portion. Is formed in the shape of a well, and in a synthetic resin four-sided pallet having an opening on the back surface where the fork insertion hole intersects, a portion connecting the tubular girder at the middle portion and the tubular girder at the center portion on the back portion is provided. The present invention relates to a synthetic resin pallet, wherein an inclined rib or an inclined surface formed at an end portion on a fork insertion side is connected to a crosspiece having a horizontal plate-like portion. Further, the present invention provides
In molding the heat sink, the thermoplastic resin is integrally formed in the mold.
Integral molding of synthetic resin pallets characterized by shaping
Method.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing an example of the synthetic resin pallet according to the present invention, FIG. 2 is a bottom view of the synthetic resin pallet shown in FIG. 1, FIG. 3 is a front view of the synthetic resin pallet shown in FIG. FIG. 2 is a cross-sectional view of the synthetic resin pallet shown in FIG. 1 taken along the line II. FIG. 5 is a partial sectional view showing another embodiment, and FIGS. 6 and 7 are sectional views for explaining a method for molding the synthetic resin pallet shown in FIG.

A pallet made of synthetic resin is integrally injection-molded with a synthetic resin such as polyethylene or polypropylene, and has a front surface portion 1 and a back surface portion 2. A cylindrical girder 3 at the corner connecting the corners, a cylindrical girder 4 at the middle connecting the middle part around the front part 1 and the back part 2, and a center part between the front part 1 and the back part 2. Connected by a central tubular girder 5 to be connected,
A fork insertion hole 6 is formed between the tubular girders 3, 4, and 5 in the shape of a well.

In order to increase the strength, a partition plate 7 whose upper end reaches the front surface portion 1 and whose lower end reaches the back surface portion 2 is provided diagonally crossing inside the tubular girder 5 at the center. I have.

A beam 8 is formed on the surface portion 1 between the intermediate tubular girder 4 and the central tubular girder 5, and the bar 8 is formed of the intermediate tubular girder 4 and the central tubular girder. 5 has a の 間 -shaped cross section. It is preferable that the surface portion 1 located above the portion where the fork insertion hole 6 intersects vertically and horizontally is constituted by bars 9 and 10 intersecting vertically and horizontally.

The front part 1 and the back part 2 connecting the cylindrical girder 3 at the corner and the cylindrical girder 4 at the middle part are constituted by bars 11, 12, 16, 17 which cross vertically and horizontally. Is preferred.

The cross section of the pallet, in which the fork insertion holes of the pallet intersect each other vertically and horizontally, is constituted by a crossing bar, and the cylindrical girders 3 at the corners of the front and back surfaces and the cylindrical shape at the middle are formed. If almost all of the portions connecting the beams 4 are formed of crossed bars, the strength of the pallet is significantly improved.

On the back surface portion 2, between the cylindrical girder 4 in the middle part and the cylindrical girder 5 in the central part, cross-sections 13 and 13 'having a Π-shaped cross section are formed so as not to vertically overlap with the cross-section 8. The crossbar 13 'is crossbar 1.
3 are formed bilaterally symmetrically, and the crosspiece 13 ′ is made up of a horizontal plate-shaped portion 14 and an inverted U rising from an end of the horizontal plate-shaped portion 14.
And a plurality of inclined ribs 15 connected to the horizontal plate-shaped portion 14. A plurality of holes 42 for draining water can be provided in the horizontal plate portion 14. The reason why the bars 13 and 13 'are formed in a square shape or an inverted U shape is to prevent water, dust and the like from accumulating. In addition, since the inclined rib 15 is connected to the horizontal plate-shaped portion 14, the V-shaped guide attached especially to the front of the wheel when the hand lifter is taken in and out can be used.
3 'will not be caught. In some cases, the inclined rib 15 can be used even if it is an inverted V-shaped portion connected to a crosspiece having no horizontal plate-shaped portion. Further, an inclined surface may be used instead of the inclined rib 15.

In the pallet of the present invention, the inclined rib or the inclined surface is a portion connecting the corner cylindrical girder and the intermediate cylindrical girder on the back surface, and the intermediate cylindrical girder and the central cylindrical girder. Are provided at the fork insertion side end and the opening side end on the side facing the fork insertion hole in the portion connecting the two.

The inclined ribs 15 or inclined surfaces are provided so that the forks or wheels of the hand lifter can smoothly pass through the crosspieces 13 and 13 ', and have an angle suitable for the wheel guide of the hand lifter to pass smoothly. .

A portion of the back surface portion 2 connecting the cylindrical girder 3 at the corner portion and the cylindrical girder 4 at the middle portion has a cross section T crossing vertically and horizontally.
The crossbars 16 and 17 are provided, and inclined ribs 18 are provided at the insertion end and the opening 19 end of the fork. You can pass through. As can be seen from FIG. 3, it is preferable that a horizontal plate-like portion connecting the bars 16 and 17 is formed on the wheel passage side of the fork of the bars 16 and 17 and the inclined rib 18, and such a horizontal plate-like portion is formed. This further improves the strength of the pallet. If necessary, a drain hole 42 can be provided in the plate portion. Note that an inclined surface may be used instead of the inclined rib 18.

A large opening 19 is formed at the back surface of the portion where the fork insertion holes 6 intersect. FIG. 5 shows another example that is partially different, and is a cross-sectional view of the back surface 2 connecting the cylindrical girder 3 at the corner and the cylindrical girder 4 at the middle. The inclined portion is the inclined surface 20, so that the fork can be taken in and out more smoothly and the strength can be increased.

The pallet of the present invention is formed, for example, by the following method. A tubular girder having a front surface portion and a back surface portion, and a front surface portion and a back surface portion connecting the corner portions of the front surface portion and the back surface portion, and an intermediate portion connecting the middle portions around the front surface portion and the back surface portion. The cylindrical girder and the central part of the front part and the rear part are connected by a central part girder connecting the central part of the back part, and a fork insertion hole is formed between the cylindrical girder in a cross shape, and the fork insertion hole intersects The opening on the back side to be formed, almost all of the part connecting the cylindrical girder of the corner and the cylindrical girder of the middle part on the front and back sides is constituted by a cross bar which crosses vertically and horizontally, and A fork insertion side end facing a fork insertion hole in a portion connecting the cylindrical girder in the corner and the cylindrical girder in the middle and a portion connecting the cylindrical girder in the middle and the cylindrical girder in the middle; Injection molding of synthetic resin pallets provided with inclined ribs or inclined surfaces at the opening end There are, using the slide core for forming a moving mold and the fork insertion holes in contact with the fixed mold and the back side in contact with the pallet surface,
In addition to using the upper slide core and the lower slide core that slide each other by the dovetail groove provided on the slope, the lower slide core comes forward before the upper slide core when closing the mold during molding. In this state, the slide core is advanced to a predetermined position, and then the upper slide core is advanced to a predetermined position, and the lower slide core is pushed into the movable mold side. When the slide core and the movable mold have a predetermined positional relationship, the positional relationship is maintained. The movable mold is moved toward the fixed mold while the mold is closed, and the mold is closed.In opening the mold, the movable mold is retracted in the mold opening direction with the molded product attached to the movable mold, and then moved upward. The slide core is retracted in the direction perpendicular to the mold opening direction of the movable mold, and the lower slide core is moved in the mold closing direction of the movable mold by an amount that allows the inclined ribs or the inclined surfaces to move sufficiently. Further the rear on the slide core and the lower slide core simultaneously molding a synthetic resin pallet by retracting. According to such a forming method, it is possible to easily form the undercut portion facing the fork insertion hole inside the structure portion of the pallet.

Hereinafter, a method of forming a pallet according to the present invention will be described in detail with reference to FIGS. FIG.
Denotes a fixed mold 30, a movable mold 31, an upper slide core 32,
FIG. 4 is a partial cross-sectional view of a state in which the lower slide cores 33 are each opened. In order to perform molding from the state shown in FIG. 6, mold closing is started.

First, the rod 36 is moved by a hydraulic cylinder.
Is moved to the left in the figure. Accordingly, the upper slide core 32 fixed to the rod 36 and a spring (not shown) that is slidably assembled with the upper slide core 32 and the dovetail structures 34 and 34 ′ and is housed in the dovetail structure. 2), the lower slide core 33 that does not slide with respect to the upper slide core 32 with a small force is advanced leftward.

When the lower slide core 33 reaches the position shown by the one-dot chain line, the lower slide core 33 hits the leftward moving die 31 and stops. From that state, the rod 36
When the upper slide core 32 advances leftward while sliding on the lower slide core 33, the lower slide core 3
3 is pushed down.

When the upper and lower slide cores 32 and 33 and the movable mold 31 are set at predetermined positions, they move toward the fixed mold 30 while maintaining the positional relationship. Then, the state shown in FIG. 7 is reached, and the mold closing is completed.

After the injection of the resin into the cavity is completed and the cooling is completed, the mold is opened. Fig. 7
From the state of FIG.
3 together with the mold opening direction, that is, downward in the drawing.
At this time, the molded product moves while adhering to the moving mold and the slide core. The moving mold is retracted to a predetermined position, and then
The upper slide core 32 is retracted by the rod 36 in a direction perpendicular to the mold opening direction of the movable mold. At this time, since the outer end portion 38 of the lower slide core 33 contacts the block 35, the lower slide core 33 does not retreat to the right and moves in the mold closing direction of the movable mold, that is, moves upward in the drawing. When the upper slide core 32 and the lower slide core 33 are at the positions shown in FIG. 8, the lower slide core 33 completely clears the undercut formed by the inclined portion 40 of the molded product, and the lower slide core end 38 also has It is above the block 35, and thereafter, the upper slide core 32 and the lower slide core 33 are further retracted rightward while maintaining the related position. Then, the state shown in FIG. 6 is reached and one molding cycle is completed.

In performing the above-mentioned molding, it is preferable to secure the height H of the block 35 = the amount of undercut h + several mm, and the sliding angle between the upper slide core 32 and the lower slide core 33 is 15 °. Before and after is preferred.

[0024]

According to the present invention, there is provided a four-way pallet made of synthetic resin, which makes it very easy to take out and put in the hand lifter and to reduce damage to the crosspiece between the middle tubular part and the central tubular part on the back surface due to the taking out and putting in of the hand lifter. Can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view of a pallet showing an embodiment of the present invention.

FIG. 2 is a bottom view of the pallet of FIG. 1;

FIG. 3 is a side view of the pallet of FIG. 1;

FIG. 4 is a sectional view taken along the line II of FIG. 1;

FIG. 5 is a partial sectional view of a pallet showing another embodiment of the present invention.

FIG. 6 is a schematic view of a mold for explaining a method of forming the pallet shown in FIG.

FIG. 7 is a schematic diagram of a mold for explaining a method of forming the pallet shown in FIG.

8 is a schematic view of a mold for explaining a method of forming the pallet shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Front part 2 Back part 3,4,5 Cylindrical girder 6 Fork insertion hole 8,9,10,11,12,13,13 ', 16,17
Cross bars 15, 18 Inclined rib 19 Opening 20 Slope 30 Fixed mold 31 Moving mold 32 Upper slide core 33 Lower slide core 41 Inverted U-shaped part 42 Hole

Claims (2)

(57) [Claims] A cylindrical girder having a front surface portion and a rear surface portion, wherein the front surface portion and the rear surface portion connect the corner portions of the front surface portion and the rear surface portion, and an intermediate portion around the front surface portion and the rear surface portion. Are connected by a central tubular girder connecting the middle part and a central tubular girder connecting the front part and the central part of the back part, and a fork insertion hole is formed in a well shape between the tubular girders. In a synthetic resin four-sided pallet having an opening on the back surface where the fork insertion holes intersect, the fork insertion side end of the portion connecting the middle tubular girder and the center tubular girder on the back surface is formed. A pallet made of synthetic resin, wherein the inclined ribs or inclined surfaces are connected to a crosspiece having a horizontal plate-like portion . 2. A cylindrical girder having a front surface portion and a rear surface portion, wherein the front surface portion and the rear surface portion connect corners of the front surface portion and the rear surface portion to each other,
It is connected by the cylindrical girder of the middle part connecting the middle part of the periphery of the front part and the back part and the center part of the girder connecting the center part of the front part and the back part, and between the cylindrical girder. The fork insertion hole is formed in the shape of a well and has an opening on the back surface where the fork insertion hole intersects, and the fork insertion side of a portion connecting the middle tubular girder and the central tubular girder on the back surface In molding a synthetic resin pallet in which an inclined rib or an inclined surface formed at an end is connected to a crosspiece having a horizontal plate-like portion, a thermoplastic resin is integrally molded in a mold. An integrated molding method for a synthetic resin pallet.