JPH11100035A - Synthetic resin pallet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin pallet to generate no recesses caused by the shrinkage on a surface of a deck board while being light in weight ;end large in bending strength. SOLUTION: In a synthetic resin pallet in which pellet forming members 10 of the shape where a pallet is split into upper and lower part are injection- molded, and opposite to each other and integratedly deposited with each other, the pallet forming members 10 include a deck board 11 to form a loading surface, and a thin-walled girder forming member 12 and reinforcement ribs 13, 14 which are intersected with each other, thick on the deck board side, and tapered so as to be slender toward an end part, are provided on the inner side of the deck board 11. In particular, a hollow part blown in during the injection molding is formed along the reinforcement rib 13 inside the thickest walled part in the vicinity of an intersection with the deck board 11.

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, and more particularly to a pallet for a forklift used for carrying, moving, and storing articles.

[0002]

2. Description of the Related Art Conventionally, synthetic resin pallets have been manufactured and used as forklift pallets.
Usually, this type of synthetic resin pallet is basically formed by injection molding a pallet forming member having a shape in which the pallet is divided into upper and lower portions at a girder portion, and is formed by integrating these two pallet forming members. You.

That is, a pallet forming member formed by injection molding includes a deck board for forming a loading surface,
A spar forming member (leg forming member) provided at an appropriate position on the inner surface of the deck board, and reinforcing ribs provided on the inner surface of the deck board so as to intersect vertically and horizontally are provided. The beam forming members are butted together, and the butted portions are welded and integrated.

[0004] Forming such reinforcing ribs on the inner surface of each pallet forming member increases the bending strength of the deck board and prevents the deck board from being bent when a load is carried or moved by a forklift. It is well known that it is extremely effective in doing so.

[0005]

As described above, such a reinforcing rib has a great effect in that the bending strength of the deck board is increased, but the weight of the synthetic resin pallet is correspondingly increased. was there. In addition, there is also a problem that heat easily stays at the intersection between the deck board and the ribs during molding, and solidification is delayed, so that sinks occur and the surface of the deck board is depressed into a rib shape.

Further, when a synthetic resin pallet is formed, a groove may be formed on the surface of the deck board located immediately above the reinforcing rib 1, and a band-shaped non-slip may be arranged in this groove. As shown in the figure, the bottom surface of the groove 4 is concavely concaved due to the above-mentioned “sinking”.
There is also a problem that even if the non-slip 5 is disposed, the non-slip 5 does not function effectively.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and it is possible to provide a composite material which is lightweight and has a large bending strength, but does not generate a depression due to sink marks on the deck board surface. An object of the present invention is to provide a resin pallet.

[0008]

SUMMARY OF THE INVENTION The present invention is a synthetic resin pallet, and is configured as follows to achieve the above-mentioned technical object. That is, the present invention is a synthetic resin pallet in which a pallet formed by dividing a pallet into upper and lower parts is formed by injection molding, and these are opposed to each other and welded and integrated. A deck board that forms a surface, a girder provided on the deck board, and reinforcing ribs that are provided vertically and horizontally on the inner surface of the deck board, are thick on the deck board side, and are tapered so as to become thinner at the tip end. In the reinforcing rib, a hollow portion formed by blowing gas at the time of molding is formed along the reinforcing rib inside the thickest portion near the intersection with the deck board. It is characterized by being.

<Specific Structure of the Present Invention> The synthetic resin pallet of the present invention comprises the above-mentioned essential components, but is also established when the components are specifically as follows. The specific component is that a reinforcing portion is provided with a curved portion at the thickest portion near the intersection with the deck board, and the size of the hollow portion is controlled by the size of the curved portion. And

Further, in the synthetic resin pallet of the present invention,
It is also preferable that a groove is formed substantially along the reinforcing rib on the deck board surface immediately above the hollow portion formed in the reinforcing rib, and a non-slip is arranged in this groove.

Further, in the synthetic resin pallet of the present invention,
A pallet forming member is formed at an end of the spar forming member adjacent to the fork insertion hole to form a relatively small closed hollow portion by dividing an internal space of the spar forming member. It is also desirable that the thickness of the deck boat surface in the closed hollow portion to be formed is thicker than the other surfaces.

Further, in the synthetic resin pallet of the present invention, the pallet forming member divides the internal space of the spar forming member into an inner space at an end portion of the spar forming member adjacent to the fork insertion hole and is relatively small. It is preferable that a closed hollow portion is formed, and the vertical and horizontal dimensions of the closed hollow portion located at the corner of the pallet forming member are each 30 to 80 mm.

Further, in the synthetic resin pallet of the present invention,
It is also preferable to apply a graining process to a part or the entire surface of the deck board in the pallet forming member. Also,
It is also preferable that the position of the grommet attached to the fork insertion hole of the pallet forming member to prevent slippage between the forklift claw and the forklift claw is within 200 mm from the edge of the deck board.

According to the synthetic resin pallet of the present invention, as a whole, a pallet forming member having a shape obtained by dividing the pallet into upper and lower portions is formed by injection molding, and these are formed by opposing and welding and integrating. When each pallet forming member is formed by injection molding, the deck is injected by injecting gas from a predetermined position into a portion of the reinforcing rib on the deck board side before the inside of the reinforcing rib provided vertically and horizontally on the inner surface of the deck board is solidified. A hollow portion is formed near the intersection with the board.

As a result, the thick portion of the reinforcing rib at the intersection with the deck board becomes substantially thin due to the presence of the hollow portion, and as a result, the cooling rate becomes extremely slow as compared with other portions. Absent. Therefore, the surface of the deck board immediately above the reinforcing ribs is free from depressions and the like due to sink marks, and the smoothness of the deck board surface can be obtained. Also, the whole surface of the anti-slip protrudes slightly from the deck board surface uniformly and becomes parallel, so that its performance can be sufficiently exhibited.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a pallet made of synthetic resin according to the present invention. FIG. 1 shows a further quarter portion of an upper half pallet forming member 10 in which a synthetic resin pallet according to an embodiment of the present invention is divided into upper and lower halves.
The pallet forming member 10 is provided on the inside of the deck board 11 in the same manner as the deck board 11 and the spar forming members or the leg forming members 12 formed at both ends and an intermediate portion inside the deck board 11. The reinforcing rib 13 is provided.

The synthetic resin pallet according to this embodiment is
The pallet forming members 10 are opposed to each other, and the beam forming members 12 are butted, and the butted portions are welded and integrated. The girder forming member 12 has a cylindrical shape,
It is preferable to form it with a thin thickness of about 7 mm. Space (hole) between girders when seeing a synthetic resin pallet from the side
Is a fork insertion hole 15.

Reinforcing ribs are provided on the inside of the deck board 11 so as to intersect vertically and horizontally, and are also formed on the inner surface of the deck board along the entrance 16 of the fork insertion hole 15, that is, the opening 16 of the fork insertion hole 15. Fork insertion hole 1
The reinforcement ribs formed on the inner surface of the deck board 11 along the opening 16 of the fifth member 5 are indicated by another reference numeral 14 for convenience of explanation.
Is shown with

The edge reinforcing ribs 14a formed on the inner surface of the deck board 11 along the opening 16 of the fork insertion hole 15 and especially at the edge thereof are connected to the reinforcing ribs 13 formed in parallel with and adjacent to the edge. Are connected to each other by a large number of connecting reinforcing ribs 14b spaced at a predetermined interval from each other. Thus, the edge reinforcing rib 14a is connected to the adjacent reinforcing rib 1
By connecting the plurality of reinforcing ribs 3 with the plurality of connecting ribs 14b, the impact strength of the deck board 11 near the fork insertion hole 15 can be further increased.

Now, reinforcing ribs 14a, 14b formed on the inner surface of the deck board 11 along the fork insertion hole 15
As shown in FIG. 2, the reinforcing ribs 13 formed inside the deck board 11 can be formed so as to be thicker on the deck board side and tapered so as to become thinner at the tip end. However, especially for the reinforcing ribs 13,
A hollow portion 17 blown during molding is formed along the reinforcing rib 13 inside the thickest portion near the intersection with the deck board 11.

One method of providing the hollow portion 17 in the vicinity of the intersection of the reinforcing rib 13 with the deck board 11 is as follows. That is, the reinforcing ribs 13
One or a plurality of gas injection holes (not shown) are provided in the pallet molding die so as to correspond to positions directly above and along the deck board surface.

When the molten resin is injected from the above-described gas injection hole or a separately provided hole for injection of the molten resin and the pallet forming member 10 is injection-molded, the gas injection hole is formed before the inside of the reinforcing rib 13 is solidified. A suitable gas, such as air or nitrogen, is injected from the apparatus. The gas injected from the above-described gas injection hole enters the thick portion near the intersection of the reinforcing rib 13 with the deck board 11 along the reinforcing rib 13 and forms a hollow portion 17 therein.

Accordingly, the hollow portion indicated by reference numeral 17 in FIG. 2 is also a conduction path for the injected gas formed in the thick portion near the intersection of the reinforcing rib with the deck board, and is formed through the same gas injection hole. The passages are all in communication with the hollow portions 17 of the reinforcing ribs 13. As described above, when the molten resin is injected into the mold and molded, a method of forming a hollow portion in the reinforcing rib by blowing a gas such as air or nitrogen before the molten resin injected into the mold is solidified. Is well known as a gas injection method, and a detailed description of this method will be omitted.

The internal pressure of the gas blown into the reinforcing ribs 13 acts uniformly on the inner wall of the mold portion, so that the thickness of the formed reinforcing ribs 13 does not become extremely thin. By forming the hollow portion 17 in the reinforcing rib in this manner, effects such as a reduction in the weight of the synthetic resin pallet, a reduction in dimensional fluctuation during molding, and a reduction in molding time are obtained.

The amount of gas injected into the reinforcing ribs 13 during the injection molding of the pallet forming member 10 is adjusted according to the required strength of the synthetic resin pallet 10 and the like. Usually, it is preferable to inject gas so that the apparent density of the entire synthetic resin pallet is about 0.75 to 0.95 times the density of the raw synthetic resin.

A curved portion 25 is provided in the thickest portion of the reinforcing rib 13 near the intersection with the deck board 11, as shown in FIG. 2 or 3, and the size of the curved portion is appropriately adjusted. By designing, the size of the hollow portion 17 can be controlled. By providing the curved portion 25 and increasing the substantial wall thickness in this manner, the flow of gas is promoted, and the formation of the gas flow path can be facilitated. As a result, the gas can flow into the intended place.

In the synthetic resin pallet, a groove 18 is formed on the deck board surface immediately above the predetermined reinforcing rib 13 and a non-slip 19 is arranged in the groove 18. At this time, since the hollow portion 17 is formed inside the vicinity of the intersection of the reinforcing rib 13 with the deck board 11 as described above, no depression is formed on the bottom surface of the groove 18 by “sink” as described above. .

Therefore, as shown in FIG. 3, the surface of the non-slip 19 slightly protruding from the surface of the deck board 11 can be positioned almost parallel to the surface of the deck board, and as a result, the function of the non-slip 19 is sufficient. Can be demonstrated.

Next, the end of the beam forming member 12 adjacent to the fork insertion hole 15, in other words, the fork insertion hole 1
The structure at the ends of the spar forming members 12 located on both sides of 5 will be described. Inside the end of the girder forming member 12 adjacent to the fork insertion hole 15, the girder forming member 12
A relatively small closed hollow portion is formed so as to divide the internal space.

More specifically, the closed hollow portion will be described. FIG. 1 shows a further quarter of the upper half pallet forming member 10 as described above. The member 12 is located at the outer end of the pallet forming member 10, and the left spar forming member 12 represents half of the spar forming member located in the middle of the pallet forming member 10.

The hermetically sealed hollow portion of the spar forming member 12 at the outer end portion is formed as shown by reference numerals 20a, 20b and 20c.
And the beam forming member 12 located in the middle portion is composed of a total of six sealed hollow portions (half closed hollow portions 2 in FIG. 1).
0d, 20e, and 20f).

The closed hollow portions 20a to 20f are formed by the side wall 12a and the end wall 12b at the end of the beam forming member 12.
Is formed by a partition wall 21 which cooperates with the above.
The partition wall 21 has a first partition portion 21a formed therebetween so as to be substantially perpendicular to the side wall 12a of the spar along the longitudinal direction of the fork insertion hole 15, that is, the insertion direction of the fork.

The partition wall 21 is further divided into two space portions defined by the first partition portion 21a and the side walls 12a and the end walls 12b of the spar forming member 12 so as to divide the space portion into two spaces parallel to the fork insertion direction. Two partition portions 21b are provided. As a result, the girder 1 adjacent to the fork insertion hole 15
With respect to the second end, the strength against impact from the fork insertion direction can be improved.

Incidentally, the corners of the synthetic resin pallet are susceptible to impact during use, and it is particularly necessary to reinforce this portion. Therefore, the pallet forming member 10
Of the hollow hollow portion 20a at the corner provided in the girder forming member 12 at the outer end of the second partition portion 21
It is preferable that the distance A between the first partition 21a and the side wall 12a and the distance B between the first partition 21a and the end wall 12b are both about 30 to 80 mm.

The closed hollow portion 20a is
Further, the thickness of the deck boat surface in the portion is 3 to 5 mm.
And is formed to be 1 to 3 mm or more thicker than other surfaces. However, since the surface of the deck board is entirely flat, the increased thickness is increased inside the closed hollow portion 20a.

Next, the injection molding conditions for the pallet forming member 10 will be described. The injection molding conditions of the pallet forming member 10 may be ordinary conditions. For example, when high-density polyethylene is used as a material, the melting temperature (cylinder temperature)
200-250 ° C, injection rate 2000-5000cc / s
The condition of about ec is preferable. Further, as a synthetic resin constituting the pallet, polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer or the like is generally used, but it goes without saying that other resins may be used in some cases.

Further, it goes without saying that additives such as a coloring agent and a filler may be appropriately used. Furthermore, a foaming material may be mixed with these synthetic resins by mixing a conventionally known blowing agent including a commonly used organic or inorganic one. The foaming ratio in this case is desirably about 1.01 to 1.4 times. In this case, the apparent density of the entire pallet is preferably about 0.65 to 0.95 times the density of the raw synthetic resin.

In the synthetic resin pallet according to the above-described embodiment, the reinforcing ribs 13 and 14 provided inside the pallet forming member 10 are formed so as to extend in a direction parallel to and perpendicular to the fork insertion direction. In the present invention,
Except for the edge reinforcing ribs 14a formed at the edges of the deck board 11 along the fork insertion holes, there is no reason to limit the extending direction of the reinforcing ribs to such a direction.

In FIG. 1, reference numeral 22 indicates that when the present synthetic resin pallet is used, when the fork is inserted into the fork insertion hole 15, relative sliding between the fork and the synthetic resin pallet does not occur. 2 shows a non-slip rubber grommet press-fitted into a hole formed in the hollow reinforcing rib 13.

It has been confirmed that the mounting position of the grommet 22 within about 200 mm from the end of the deck board 11 functions most effectively as slip prevention when a fork is inserted into the fork insertion hole 15. That is, when loading or unloading a load on a truck or the like, a fork (claw) of a forklift is inserted shallowly into the fork insertion hole 15 of the pallet, and the pallet position is finely adjusted while pushing or pulling the pallet. . In such a case, it is most preferable that the grommet 22 is in the above-described position.

In FIG. 1, reference numeral 23 denotes an opening for a handle formed in the deck board 11 for use when lifting or tilting the synthetic resin pallet, and reference numeral 24 denotes an inner side of the deck board 11. 5 shows a drain hole for draining water that has entered from the fork insertion hole 15 or the like.

Further, a part or the entire surface of the deck board of the pallet forming member 10 is subjected to graining. As is well known, this graining process is to add a myriad of small protrusions and wrinkle-like patterns by embossing, and this makes the deck board surface rough, so the part number and destination are choked with chalk etc. It will be easier to write.

When the surface of the deck board of the pallet forming member 10 is roughened by crimping as described above, the contact surface of the load placed on the deck board surface during use of the synthetic resin pallet is reduced. With a similar rough surface, slippage is reduced due to the engagement between the rough surfaces, and safety during use can be achieved.

[0044]

As described above, according to the synthetic resin pallet of the present invention, the reinforcing rib formed on the inner surface of the deck board has the thickest portion near the intersection with the deck board inside the thickest portion. By forming a hollow part along the reinforcing rib by blowing gas during molding,
While improving the bending strength and reducing the weight of the synthetic resin pallet, it is possible to prevent the occurrence of depression due to sink marks on the deck board surface, and to improve the smoothness of the deck board surface.

Further, according to the synthetic resin pallet of the present invention, since there is no depression due to sink marks on the deck board surface as described above, even when a groove is formed at that position and a non-slip is arranged. Since the position of the non-slip surface is formed as designed, the function of the non-slip can be sufficiently exhibited.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a further quarter portion of an upper half pallet forming member in a synthetic resin pallet according to an embodiment of the present invention, which is formed by integrating vertically divided pallet forming members. It is.

FIG. 2 is a cross-sectional view of the pallet forming member shown in FIG. 1 taken along line 2-2 to show reinforcing ribs.

FIG. 3 is a cross-sectional view of the pallet forming member shown in FIG. 1 taken along line 3-3 to show reinforcing ribs.

FIG. 4 is a fragmentary sectional view showing reinforcing ribs and a deck board portion at the base thereof in a conventional synthetic resin pallet.

FIG. 5 is a cross-sectional view showing a fragmentary view of a deck board part provided with a non-slip and a reinforcing rib formed immediately below the conventional synthetic resin pallet.

[Explanation of symbols]

 Reference Signs List 10 Pallet forming member 11 Deck board 12 Girder forming member (leg forming member) 12a Side wall of girder 12b End wall of girder 13 Reinforcing rib 14 Reinforcing rib 14a Reinforcing rib 14b Reinforcing rib for connection 15 Fork insertion hole 16 Fork insertion hole 17 Hollow part 18 Groove 19 Non-slip 20 Sealed hollow part 21 Partition wall 21a First partition part 21b Second partition part

Claims (7)

[Claims] 1. A synthetic resin pallet formed by injection molding a pallet forming member having a shape obtained by dividing a pallet into upper and lower parts, and opposing each other by welding and integrating the pallet with the loading surface. And a girder forming member provided on the deck board, and reinforcement provided vertically and horizontally on the inner surface of the deck board, which is thicker on the deck board side and tapered so as to be thinner at the tip end. In the reinforcing rib, a hollow portion formed by blowing gas at the time of molding is formed along the reinforcing rib inside the thickest portion near the intersection with the deck board. A pallet made of synthetic resin. 2. The method according to claim 2, wherein the reinforcing rib is provided with a curved portion at a thickest portion in the vicinity of the intersection with the deck board, and the size of the hollow portion is controlled by the size of the curved portion. The synthetic resin pallet according to claim 1, wherein: 3. A groove is formed in the surface of the deck board immediately above the hollow portion formed in the reinforcing rib, substantially along the reinforcing rib, and a non-slip is disposed in the groove. 2. The synthetic resin pallet according to 1. 4. The pallet forming member has an inside at an end of the spar forming member adjacent to a fork insertion hole,
A relatively small closed hollow portion is formed by dividing the internal space of the spar forming member, and the thickness of the deck boat surface in the closed hollow portion located at the corner of the pallet forming member is formed thicker than the other surfaces. The synthetic resin pallet according to claim 1, wherein 5. The pallet forming member has an inside at an end of the beam forming member adjacent to a fork insertion hole,
The internal space of the spar forming member is divided to form a relatively small closed hollow portion, and the vertical and horizontal dimensions of the closed hollow portion located at the corner of the pallet forming member are each 30 to 80 mm. The synthetic resin pallet according to claim 1, wherein: 6. The synthetic resin pallet according to claim 1, wherein a part or the entire surface of the deck board of the pallet forming member is subjected to a crimping process. 7. A grommet attached to a fork insertion hole of the pallet forming member to prevent slippage between the forklift claw and the pallet forming member, wherein a position of the grommet is within 200 mm from an end of the deck board. Item 6. A synthetic resin pallet according to item 1.