JPH032748B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pallet used as a loading platform when transporting accumulated cargo by a forklift.

Conventional pallets are constructed using wood, iron, or a combination of these materials. It is made of fixed board material.

It is true that the pallets mentioned above have sufficient strength, but the pallets themselves are extremely heavy, and even when moving only the pallets, it is often difficult for one person to move them. Incidentally, the weight of pallets currently in use ranges from 30Kl to 100Kg per piece, although it varies depending on the type of cargo. Therefore, it is necessary to rely on the power of a forklift to organize pallets at the site, which has the disadvantage of poor work efficiency.

In addition, because conventional pallets are made of hard materials, they are susceptible to damage to cargo due to small impacts.In addition, repeated use can cause the surface to become rough and cause hangnails, which increases the risk of damage to cargo (such as paintwork). This not only makes it easier to damage equipment, parts, etc., but also causes injuries to workers.

The present invention solves the above-mentioned conventional drawbacks,
To provide a pallet that has sufficient strength as a platform for loading heavy objects, is light, and has little fear of damage to cargo or injury to workers.

That is, the present invention is a foamed bead molded article of polyolefin synthetic resin having a density of 0.05 to 0.2 g/cm ³ and a flexural modulus of 50 to 500 Kg/cm ² , in which a frame-shaped fitting portion is formed protruding from one side. The upper plate and the lower plate, which are plate-like objects, are integrally overlapped with their fitting parts fitted to each other, and between the fitting parts that are fitted to each other, To provide a polyolefin foam pallet characterized in that a fork insertion path for inserting a fork of a forklift is formed across the upper plate and the lower plate.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a perspective view showing one embodiment of a pallet according to the present invention, and FIGS. 2a and 2b are perspective views showing an upper plate and a lower plate, respectively.

The pallet of the present invention is a foamed bead molded body made of polyolefin synthetic resin, and includes an upper plate 1 which is a plate-like object having fitting parts 1a and 1b formed to protrude from one side, and an upper plate 1 which is formed to protrude from one side. Fitting part 2
It consists of a lower plate 2, which is a plate-like material having parts a and 2b. Fitting parts 1a, 1b and fitting parts 2a, 2
b, the fitting parts 2a and 2b are the fitting parts 1a and 1b, respectively.
The upper plate 1 and the lower plate 2 are integrally overlapped by this fitting. Between the fitting part 1a at the center of the upper plate 1 and the left and right fitting parts 1b, and between the fitting part 2a at the center of the lower plate 2 and the left and right fitting parts 2b, there are the upper plate 1 and the lower plate 2, respectively.
Appropriate intervals are provided across the area. Since the upper plate 1 and the lower plate 2 are fitted and integrated with this spaced portion facing each other, there is no space between the fitting parts 1a and 2a and the fitting parts 1b and 2b that are fitted to each other. A fork insertion path 3 for inserting a fork of a forklift is formed across the upper plate 1 and lower plate 2.

Since a normal forklift has two forks, the fork insertion path 3 can be made into a pair of two strips to match this, but when using a special forklift that has three or more forks, the fork insertion path 3 In line with this, three or more strips are formed as a pair.

The planar shape of the pallet is usually rectangular, but
In order to improve the turning radius even slightly during transportation by forklift, the four corners may be cut out, or other special shapes may be formed to match the shape of the target cargo. In addition, the upper and lower surfaces of the pallet are normally flat surfaces, but in cases where the target is cargo with a certain shape, the upper and lower surfaces are shaped like the cargo in order to improve the stability of the cargo during transfer. It is also possible to form a matching recess into which the bottom of the cargo fits. Since the pallet of the present invention is an in-mold foam molded product made of foamed synthetic resin particles as described below, such recesses can be easily formed.

In particular, the pallet of the present invention has a density of 0.05 to 0.2 g/
cm ³ and a flexural modulus of 50 to 500 Kg/cm ² made of foamed beads made of polyolefin synthetic resin.

First of all, the reason why it must be a foamed bead molded body made of polyolefin-based synthetic resin is that synthetic resins other than polyolefin-based synthetic resin or foamed molded bodies other than foamed bead molded bodies tend to become hard when trying to obtain sufficient strength. This is because they tend to break easily, and on the other hand, if you try to obtain a product with good elasticity, you will not be able to obtain a molded product that is flexible and strong, making it impossible to obtain a molded product suitable as a support for heavy objects. In other words, synthetic resins other than polyolefin synthetic resins and foam molded materials other than foamed bead molded materials may not be able to adequately support the cargo, or even if the cargo is sufficiently supported, they may be susceptible to collisions or lifting of the forks of a forklift. The only things you can get are those that easily break under the impact of time. On the other hand, if it is a foamed bead molded product made of polyolefin-based synthetic resin,
It is possible to easily obtain a pallet that is resistant to cracking and tearing and has both sufficient ability to support heavy objects and sufficient strength.

Among polyolefin synthetic resins, polyα-olefin synthetic resins are most suitable, and the present inventor molded pallets using polyethylene beads, polypropylene beads, and ethylene-styrene copolymer beads, but none of them had good properties. Pallets were obtained, particularly those using polyethylene beads, which were good.

In order to create a pallet that has sufficient support capacity for heavy objects and has sufficient strength, the foamed bead molded bodies of polyolefin resin that make up the pallet must be
Density 0.05-0.2g/cm ³ , preferably 0.06-0.13g/cm 3
cm ³ , flexural modulus 50-500Kg/cm ² , preferably 70
~300Kg/ ^cm2 is required. Density 0.05
If it is less than g/ ^cm3 , it will be difficult to obtain sufficient strength.
If it exceeds 0.2 g/cm ³ , the weight becomes too large and it becomes difficult to obtain good back strength. Furthermore, if the flexural modulus is less than 50 Kg/cm ² , the pallet will bend more when cargo is accumulated and lifted, making it more likely to collapse, while if it exceeds 500 Kg/cm ³ , it will become too hard and break easily. Furthermore, in order to have both sufficient ability to support heavy objects and stiffness, it is of course necessary that each foamed particle is in close contact with adjacent foamed particles and well fused. It is about.

Further, the pallet of the present invention has the upper plate 1 and the lower plate 2, and the frame-shaped fitting parts 1a, 1b have small-sized frame-shaped fitting parts 2a, 2.
Since the parts b fit into each other, the mechanical resistance created between the entire inner surface of the outer frame and the entire outer surface of the inner frame is used to integrate the fitting. The reason why the upper plate 1 and the lower plate 2 are fitted together to form an integrated pallet is simply to form the fork insertion path 3, and also to allow cargo to be accumulated on both the upper and lower surfaces of the pallet. In addition to reasons such as the purpose of

In other words, from the viewpoint of strength and the ability to use both the upper and lower surfaces as cargo accumulation surfaces, the pallet is preferable to a plate-like object with a groove-shaped fork insertion path 3 formed on the lower surface. It is preferable to have a fork insertion path 3 within the thickness, and for this purpose, it is necessary to mold the upper plate 1 and the lower plate 2 separately due to restrictions in molding technology. However, simply the top plate 1
If the upper plate 1 and the lower plate 2 are simply fitted together or bonded together with an adhesive, sufficient bonding strength cannot be obtained because the upper plate 1 and the lower plate 2 are made of foam. Furthermore, since the foam used in the present invention has a certain degree of elasticity, it is likely to peel off due to repeated use. On the other hand, if the two are joined by friction fitting between the side surfaces of the frame as in the present invention, the two can be reliably joined over a wide contact surface and a strong joining force can be obtained. This strong bonding force is obtained from the use of a foam having a bending elastic modulus as described above.
This is produced by the compressive deformation and elastic deformation of b, 2a, and 2b as well as the high frictional resistance due to the bead foam, and this fit is caused by the properties of the bead foam that constitutes the pallet itself used in the present invention and this fit. The combination of these structures results in high bonding strength.

In order to obtain the above-mentioned strong bonding force, the fitting parts 1a, 1b and 2a, 2b must be fitted together to the extent that they cannot be inserted into each other without being hammered into each other, that is, the fitting is tighter than a tight fit. It is preferable that the condition is obtained.
In addition, in order to ensure that the upper plate 1 and the lower plate 2 are integrated without lifting up, the lower plate 2 side fitting parts 2a and 2b on the side that enters the inside are replaced with the fitting parts 1a and 1b on the upper plate 1 side.
It is preferable to make the protrusion amount slightly smaller than the amount of protrusion.

Lower plate 2 side fitting parts 2a, 2b on the side that goes inside
may be a mere solid protrusion instead of the frame shape as shown in the figure, but in order to reduce weight, it is preferably a frame shape with a space formed inside as shown in the figure. However, the fitting part 1 forming a frame shape
If a, 1b, 2a, and 2b are made too large, the gap between the non-contact parts between the upper plate 1 and the lower plate 2 will increase, making it easier for cargo to collapse when piled up. Sometimes, the fitting part 1
a, 1b, 2a, 2b may be divided into frame shapes of appropriate sizes, or frame-shaped fitting portions 1a, 1
Supporting protrusions may be formed within b, 2a, and 2b.

If the pallet has such a structure, the weight of the pallet can be significantly reduced because it is made of lightweight foam. As aforementioned,
While conventional pallets weigh as much as 30Kg to 100°C, the pallet according to the present invention can weigh about 10Kg to 30Kg and can be easily carried by one person. Therefore, it is easy to organize the palette, etc.
Efficient work is possible even in a narrow work space.

The pallet according to the present invention has sufficient support capacity as a platform for carrying heavy objects, but unlike conventional wood or iron pallets, it is made of a material that does not cause sharp hangnails, etc. There is no need to worry about damage or injury. In particular, there is an advantage that even if products such as painted parts are directly placed there is little risk of scratching the products.

Moreover, since the pallet according to the present invention has appropriate elasticity, it has a shock absorbing power and can effectively protect the cargo from the impact when the accumulated cargo is lifted and lowered.

FIG. 3 is a comparative example, and is a perspective view showing another example of a fitting part for integrally overlapping an upper plate and a lower plate, in which the fitting part is made up of two protrusions formed at appropriate intervals. The fitting portion 4 and the fitting portion 5, which is a single protrusion fitted between two protrusions of the fitting portion 4, are a pair.

The fitting part as shown in Fig. 3 has the advantage of being easy to manufacture due to its simple structure, but the fitting part
is deformed outwardly, making it difficult to form a tight fit as in the case of the present invention.

The structure of the fitting part in the present invention is such that the frame-shaped protrusions described in FIG. Any material can be used as long as it forms a bonded state when combined.

FIG. 4 is a perspective view showing another embodiment of the pallet according to the present invention, and FIG. 5 is a perspective view of the pallet with its upper plate and lower plate separated.

In particular, as shown in FIG. 5, the lower plate 12 has fitting portions 11a to 11d formed in a protruding frame shape and fitting portions 12a to 12d at symmetrical positions. are the fitting parts 11a to 11
It is sized to fit inside the d. Each of the fitting portions 11a to 11d and 12a to 12d is formed with two fork insertion paths 13 that cross in the vertical and horizontal directions, and in particular in this embodiment, the upper plate 11 and the lower plate 1 It has exactly the same shape. That is, the upper plate 11 is rotated 180 degrees horizontally from the illustrated lower plate 12 and is positioned above the lower plate 12. The fitting parts 12a to 12d of the plate 11 are fitted into the fitting parts 11a to 11d of the upper plate 11, and the fitting parts 12a to 12d of the lower plate are fitted into the fitting parts 11a to 11d of the upper plate 11.
The upper plate 11 and the lower plate 12 are integrally joined by being fitted.

In this way, the shapes of the upper and lower plates will be exactly the same, so only one type of mold is required to manufacture the pallets, reducing the labor and cost of mold creation. be able to.

6 to 8 show other examples of arrangement of the fitting portions, and in FIGS. 6 and 7, the fitting portions 12a to 12d are fitted into the fitting portions 11a to 11d. In FIG. 7, the fitting parts 12a to 12c are the same as the fitting parts 11a to 1.
The size is such that it can be fitted into the 1c.

When the upper and lower plates shown in FIGS. 6 and 7 are used as upper and lower plates, if the upper and lower plates are stacked facing each other with a 180° shift, the mating portions 11a to 11d of each other can be formed. and the fitting portions 12a to 2d are fitted and integrally overlapped. Furthermore, when the upper plate and the lower plate are used as shown in FIG. 8, if the upper plate and the lower plate are stacked facing each other while being shifted by 90 degrees, they will fit into each other's fitting portions 11a to 11c. The joining parts 12a to 12c are fitted together and integrally overlapped.

In addition, in addition to the fitting portions shown in FIGS. 5 to 8, the fitting portions used when plate-like objects of the same shape are used as an upper plate and a lower plate to fit and integrate them are as shown in FIGS. 5 to 8.
The structure shown in the figure and other structures can be widely adopted by devising the arrangement.

The integral overlapping of the upper plate and the lower plate in the present invention is a tight fit and can be used as is, like an integrally formed one, but it is possible to use an adhesive or a fastening means in combination with the above-mentioned fitting. You can also go with it.

An example of the fastening means will be explained with reference to FIG. 9.
A counterbore 14 may be formed on the surface of the upper plate 11 and the lower plate 12, respectively, and the upper plate 11 and the lower plate 12 may be fastened together with bolts 15 and nuts 16 while preventing protrusion from the surface.

If such fastening is used in conjunction with fitting, the connection between the upper plate and the lower plate can be made even stronger.

FIG. 10 is a perspective view showing the pallet shown in FIG. 4 with a reinforcing band 17 attached to the circumferential side thereof. The reinforcing band 17 is made of reinforced paper, plastic molded product, reinforced plastic (FRP), thin metal plate, synthetic fiber woven fabric, etc., and is fixed from the upper plate 11 to the lower plate 12 of the pallet by gluing or fastening. .

By installing such reinforcing bands, it is possible to reduce the deflection of the pallet during transportation, and it also prevents the pallet from being torn apart even if the fork of the forklift shifts from the fork insertion groove and pierces the pallet side wall. This prevents the device from becoming unusable. Moreover, the connection between the upper plate and the lower plate can be made even stronger. Of course, this reinforcing band can also be attached to the pallet shown in FIG. 1.

As explained above, according to the present invention, it has sufficient strength as a platform for heavy objects, is lightweight, and
Moreover, it is possible to obtain pallets with less fear of damage to cargo or injury to workers, and work efficiency can be greatly improved.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention;
Figure a is a perspective view of the upper plate, figure b is a perspective view of the lower plate,
FIG. 3 is a perspective view showing an example of another fitting part as a comparative example;
FIG. 4 is a perspective view showing another embodiment of the present invention, and FIG.
The figure is a perspective view of the upper and lower plates separated.
Figures 6 to 8 are plan views showing other examples of the arrangement of the fitting parts, Figure 9 is a sectional view showing an example of a fastening means used in combination, and Figure 10 is a perspective view showing an example with a reinforcing band attached. It is a diagram. 1, 11: Upper plate, 1a, 1b, 11a-11
d: Fitting part, 2a, 2b, 12a to 12d: Fitting part, 3, 13: Fork insertion path, 4: Fitting part,
5: Fitting part, 14: Counterbore, 15: Bolt, 1
6: Natsuto.

Claims (1)

[Claims] 1 Density 0.05~0.2g/ ^cm3 , Flexural modulus 50~500
The upper and lower plates are made of foamed beads molded from a polyolefin synthetic resin weighing kg/cm ² and have a protruding frame-shaped fitting part formed on one side.
The fitting parts are fitted to each other and integrally overlapped, and between the fitting parts that are fitted to each other, the fork of the forklift is inserted across the upper plate and the lower plate. A polyolefin foam pallet characterized by having a fork insertion path formed therein for insertion.