JPS61273348A - Cushioning pallet device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to a buffer pallet device.

``Prior art and problems to be solved by the invention'' As is well known, when cardboard boxes containing products are loaded onto logistics equipment such as pallets, experimental formulas are used to ensure that they can withstand the loading load. Using the design calculation formula, the material design and structural design of corrugated cardboard are performed using coefficients that take into account the static load from above and the decrease in strength during storage and distribution.

In other words, the compressive strength of the corrugated pole base paper itself, the corrugated board, etc.
In addition to the theoretical strength value determined from physical properties and constants such as panel rigidity and box size, we also calculate the coefficient of deterioration of box strength due to outside air humidity and static compressive load during storage, and the deterioration value due to vibration during distribution. The design value is the design value, and the compressive strength value of the actual product is the value that takes into account the safety value so that the theoretical strength obtained earlier can be maintained, with .

Conventionally, there has been a tendency to use the maximum value for the deterioration correction constant during storage and distribution as described above, with emphasis on safety, and a value four times or more the theoretical strength has been set as the design value and commercialized.

However, recently, as social demands such as rationalization of packaging and reduction of logistics costs have arisen, the pros and cons of designing for a strength of four times or more have come to be questioned.

In addition, the equipment for storing cardboard packaging is also being modernized, and automatic rank type multi-level warehouses have been newly constructed.
It is only a part of the whole.

Currently, there are both rank-type warehouses and high-pallet stacking types, and the strength design of cardboard boxes is required to be compatible with the latter type.

Pallet loading storage method with a safety multiple of 3
When lowered to the limit below, the moment the second pallet is stacked on top of the second pallet with a forklift, the cardboard containers on the first pallet cannot withstand the load, causing frequent bulges and buckling, and the damaged side There is a problem in that the cargo is tilted to the side, resulting in an uneven load and falling over in a short period of time.

In the past, the causes of this load were discussed, such as whether the box strength at that time did not meet the design strength, or the box moisture was higher than the design value, etc. However, regarding moisture,
After eliminating the influence of moisture brought in from inside and outside the box and confirming that there was no difference in strength between the design value and the product, we measured the amount of displacement in the height direction of the lower cardboard packaging due to loading.

As a result of weighing, large deformations such as deformation occur on the lower pallet, especially on the bottom box panel surface, at the moment the load is applied by lift handling. Note that if the impact is absorbed by all the cardboard boxes stacked underneath, the amount of displacement will remain small even if the boxes are left undisturbed for a long time.

This experiment showed that when stacking pallets, a dynamic load is applied, and the lower cardboard box naturally exceeds the design value, resulting in a large displacement of the panel, and if the interior parts cannot support this load, it will buckle. It turned out that. In addition, if the lift descends at a high speed, acceleration is added, causing even greater damage, upward acceleration, and a flying phenomenon.
The panels of the loaded cardboard box undergo positive and negative displacements, resulting in large residual strains.

In this way, dynamic loads during stacking tend to generate large gravitational accelerations because the impact time from the start of the impact until reaching the maximum value and the impact duration are short (for the lower cardboard boxes, Subject to compressive loads exceeding allowable values.

As mentioned above, the moment packaging containers or packages are loaded onto a pallet and stacked in several stages, an impact load occurs, for example,
When a forklift is used to stack pallets loaded with packages onto a pallet load, the moment the pallet leaves the forklift, the pallet is in a state of free fall, or with the added velocity of the lowering of the lift. As a result, the lower packaging body is subjected to a falling impact, deformed, compressed, and destroyed.

Therefore, methods such as designing and manufacturing cardboard containers with design values that include dynamic loads, or operating forklifts quietly and slowly can be considered, but these methods are impractical and involve high costs and It impedes work efficiency, etc.

Other proposals include using cushioning materials such as rubber for the pallet legs, and using shock absorbers, springs, dunnage, etc., but each of these has the following problems. I have it.

In other words, since it is difficult to set variable loading values for shoes 93-leg structure pallets or containers, the maximum load is set as the design value, so a hard type of cushioning material is used, and therefore, it is hoped that the impact time will be extended. Because the damping force is also small,
There is also an inherent negative effect of repulsion. Particularly, in the case of items such as cardboard boxes, which experience a large amount of distortion (displacement) due to a small load, a cushioning material with a small amount of displacement cannot be expected to be effective.

Furthermore, since the stroke of the shock absorber becomes longer depending on the magnitude of the load, a thicker pallet is required, which impedes workability. Moreover, this has a small variable setting range of the load.

Additionally, springs and dunnage cannot be used alone because they both produce repulsion (non-damping force).

An object of the present invention is to provide a buffer pallet device that can absorb impact energy generated when loaded items are stacked and prevent damage to the loaded items.

Means and operation for solving problem F" The present invention comprises a bottom plate, a top plate on which a load is loaded, a variable volume body disposed between the bottom plate and the top plate, and a and a flow restriction means that provides resistance to the flow of fluid discharged as the volume of the volumetric body decreases, and is characterized in that impact energy during loading is absorbed by the variable volumetric body and the flow restriction means. .

"Embodiments" Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 7 shows a state in which objects are loaded on the buffer pallet device to which the present invention is applied.

In FIG. 7, 100 is a buffer pallet assembly W to which the present invention is applied (this will be described in detail later), and 11
0, 120, 130 are the 1st row, 2nd row, and 3, respectively.
This is the load on the tier.

The first stage load 110 has cardboard boxes 114 stacked in three stages on a pallet 112, and similarly, the second stage load 120 has cardboard boxes 124 stacked in three stages on a pallet 122. The load 130 in the third tier is a pallet 132 with cardboard boxes 134 stacked in three tiers.

Then, the first stage load 1 is placed on the buffer pallet device 100.
10 falls in the direction of arrow 116 and is loaded, and then 1
The second stage load 120 is indicated by arrow 1 on the second stage load 110.
After that, the third-stage loaded object 130 falls in the direction of arrow 136 and is loaded on the second-tier loaded object 120.

During this loading, the buffer pallet device 1 that is compatible with the present invention
According to 00, it absorbs the impact energy that occurs instantaneously when loaded items 110, 120, and 130 are stacked, and
10.120.130(2) Damage can be prevented.

Three embodiments of the present invention will be described in detail below.

FIG. 1 shows the plane of the buffer pallet device according to the first embodiment of the present invention with the top plate removed, and FIG. 2 shows its cross section.

Between the bottom plate 10 in contact with the floor and the top plate 12 on which objects are loaded, four variable volume bodies 14 are arranged at the four corners of the plate 10.12. The bottom plate lo and the top plate 12 are made of synthetic resin, rubber, wood, metal, etc.
2 is set to approximately 10 cm. Further, the variable volume body 14 is made of rubber, plastic, polyolefin resin, etc., has elasticity and durability, and is formed with a bellows so that it can be expanded and contracted.

On the bottom plate 10, there are four
Two pressure tanks 16 are provided, each variable volume body 1
4 and the pressure tank 16 are communicated through a supply pipe 18 and a discharge pipe 20.

FIG. 3 shows the inside of the variable volume body 14, the pressure tank 16, the supply pipe 18, and the discharge pipe 20. The supply pipe 18 is provided with a check valve 22, and the discharge pipe 20 is provided with a check valve 22. An orifice 24 is formed as a flow restriction means.

The variable volume body 14 and the pressure tank 16 are filled with gas, for example, air, and the air in the pressure tank 16 is supplied to the supply pipe 1.
8 and is supplied to the variable volume body 14 through the variable volume body 14.
The air inside is discharged to the pressure tank 16 through a discharge pipe 20.

Then, when using the buffer pallet device, the variable volume body 14
The internal pressure of the top plate 1 and the internal pressure of the pressure tank 16 are balanced, and the top plate 1
Load the cargo onto 2. At the moment when the cargo is loaded, the variable volume body 14 contracts and the internal pressure increases, and the air inside the variable volume body 14 passes through the discharge pipe 20 to the pressure tank 1.
It is discharged at 6.

During this discharge, since the discharge pipe 20 is formed with an orifice 24, the amount of air discharged per unit time is limited to a small amount. Note that, as mentioned above, since the supply pipe 18 is provided with the check valve 22, the supply pipe 18 is not discharged. After that, the internal pressure of the variable volume body 14 and the internal pressure of the pressure tank 16 are When the balance is reached, the variable volume body 14 stops contracting, maintains the contracted state at that time, and holds the loaded object.

In this way, the impact energy at the moment of loading is absorbed.

After that, when the loaded items are further stacked, the instantaneous impact energy of loading is absorbed in the same way as above.
As the loads are piled up, the variable volume body 14 contracts and the top plate 12 lowers.

An elastic block-shaped stopper 26 made of rubber is provided around the bottom plate 1G, and the height of the stopper 26 is approximately 1/1/2 of the distance between the top plate 12 and the bottom plate 10 when no load is loaded. It is set to 2. Therefore, when loading, the top plate 1
2 and the variable volume body 14 contracts to 1/2, the top plate 12 is supported by the 7 pars 26, and the loaded items can withstand long-term storage.

Thereafter, when the load is removed from the top plate 12, the variable volume body 14 expands and the top plate 12 rises, and the air in the pressure tank 16 is supplied to the variable volume body 14 through the supply pipe 18. Ru. Since the supply pipe 18 is provided with a check valve 22, when the internal pressure of the pressure tank 16 and the internal pressure of the variable volume body 14 reach equilibrium, this inflow is stopped and the variable volume body 14
4 returns to its original shape.

As described above, according to the first embodiment of the present invention, impact energy at the moment of loading is absorbed, so damage at the moment of loading can be prevented. In the first embodiment, since each variable volume body 14 is provided with a pressure tank 16, tilting under an uneven load can be prevented.

Figure 4 shows the plane of a buffer pallet device according to a second embodiment of the present invention with the top plate removed, and Figure 5 shows its cross section.

In the second embodiment, one pressure tank 16 is provided and shared by four variable volume bodies 14, and the other configurations are the same as in the first embodiment. The second embodiment can also provide the same effects as the first embodiment.

Fig. 6 shows the inside of the variable volume body 14, pressure tank 16, supply pipe 18, and discharge pipe 20 of the buffer pallet device according to the third embodiment of the present invention.

The inside of the pressure tank 16 is caused by floating 28.
It is divided into a gas chamber 30 and a liquid chamber 32, and the liquid chamber 3
2 is connected to the variable volume body 14 by a supply pipe 18 and a discharge pipe 20. The gas chamber 30 is filled with a gas such as air, and the liquid chamber 32 and the variable volume body 14
is filled with a liquid such as water or oil. In addition, the first
As in the embodiment, the supply pipe 18 is provided with a check valve 22, and the discharge pipe 20 is formed with an orifice 24.

Furthermore, the floating 28 moves in the directions of arrows A and B within the pressure tank 16 as liquid is discharged to and supplied from the liquid chamber 32.

When this buffer pallet device is used, the variable volume body 14 contracts at the moment a load is loaded, and the liquid in the variable volume body 14 passes through the discharge pipe 20 to the pressure tank 16.
The floating 28 moves in the direction of the arrow, and the gas chamber 30 contracts and its internal pressure increases. During this discharge, since an orifice 24 is formed in the discharge pipe 20, the amount of liquid discharged per unit time is
limited to small amounts. In addition, as mentioned above, the supply pipe 18
is provided with a check valve 22, so that it will not be discharged through the supply pipe 18.Thereafter, when the internal pressure of the gas chamber 30 is balanced with the load of the payload, the variable volume body 14 will be , stop its contraction, maintain the current contraction state,
Holds the load.

In this way, the impact energy during the SUS is absorbed.

After that, when the loaded items are further stacked, the instantaneous impact energy of loading is absorbed in the same manner as described above.
As the loads are piled up, the variable volume body 14 contracts and the top plate 12 lowers.

Thereafter, when the loaded object is removed from the top plate 12, the gas chamber 3
0 expands, the floating 28 moves in the direction of arrow B, the liquid in the liquid chamber 32 is supplied to the variable volume body 14 through the supply pipe 18, and the variable volume body 14 expands, causing the floating 28 to move in the direction of arrow B.
2 rises. When the gas chamber 30 returns to its original volume, this inflow stops and the variable volume body 14 returns to its original shape.

As described above, according to the third embodiment of the present invention, the impact energy at the moment of loading is absorbed, so that damage to the loaded object can be prevented. In addition, as shown by the chain line in FIG. 6, an auxiliary tank 34 can be connected to the gas chamber 30 of the pressure tank 16 to increase the volume of the gas chamber.

Final Completion Note: Three loads of 600 kg were prepared for each of the buffer pallet device to which the present invention is applied and the ordinary pallet device, and the first stage load was loaded on the pallet device. On top of that, two loads were stacked simultaneously using a forklift to form a three-tier stack. The amount of height displacement of the first stage load at this time was 67 m for the normal pallet device, and 5 m for the buffer pallet device. Note that the acceleration at the time of impact was 1.8G by actual measurement.

Incidentally, in each of the above embodiments, the discharge pipe is formed with an orifice, but instead of the orifice, the discharge pipe may be formed with a thin pipe.

Also, the orifice of the discharge tube can be adjusted to change the amount of fluid discharged per hour.

Furthermore, the pressure tank may be provided with a pressure gauge to indicate the internal pressure, and may also be provided with an inlet valve for supplying fluid therein.

Next, the present invention will be explained in detail based on FIG. 8.9.

In FIG. 8, between the bottom plate 10 and the top plate 12, there is an air spring body 40 consisting of a piston 36 and a cylinder 38, and a fluid storage body 4 consisting of a piston 42 and a cylinder 44.
6 are provided, and air is sealed in the air spring body 40. Further, in the fluid container 46, gas (
The piston 42 is filled with an orifice 48, and when the piston 42 moves up and down, the gas (or liquid) inside the cylinder 44 flows through the orifice. 48, the amount of discharge is limited and the impact energy during loading is absorbed.

Note that the same air spring bodies 40 and fluid accommodation bodies 46 are arranged at the four corners between the bottom plate 10 and the top plate 12.

Further, FIG. 9 shows a buffer pallet device similar to that shown in FIG. 8. In the device shown in FIG. 9, a linear or non-linear coil spring 50 is provided in place of the air spring body 40, and the same effect as the device shown in FIG. 8 can be achieved.

"Effects of the Invention" As explained above, according to the present invention, it is possible to absorb the impact energy generated when loaded items are stacked and prevent damage to the loaded items.

[Brief explanation of drawings]

FIG. 1 is a plan view of a buffer hole left device according to a first embodiment of the present invention with the top plate removed, FIG. 2 is a sectional view taken along line II-If in FIG. 1, and FIG. FIG. 4 is a view showing the inside of the variable volume body, pressure tank, supply pipe, and discharge pipe; FIG. 4 is a plan view of the buffer pallet device according to the second embodiment of the present invention with the top plate removed; FIG. is a sectional view taken along the line V-V in FIG. 4; FIG. 6 is a diagram showing the inside of a variable volume body, a pressure tank, a supply pipe, and a discharge pipe of a buffer pallet device according to a third embodiment of the present invention; FIG. Fig. 8.9 is a diagram showing a state in which objects are loaded on the AT street pallet device to which the present invention is applied. Fig. 8.9 is a diagram showing a buffer pallet device according to an improved example of the present invention. DESCRIPTION OF SYMBOLS 10... Bottom plate, 12... Top plate, 14... Variable volume body, 16... Pressure tank, 18... Supply pipe, 20-
...Discharge pipe, 22...Check valve, 24...Orifice, 26...Block-shaped stop valve s2B...Floating, 30...Gas chamber, 32...Liquid chamber, 34
... Auxiliary tank, lOO... Buffer pallet device to which the present invention is applied, 110.120.130... Load,
112.122.132... Palette, 114.12
4.134... corrugated pole box. Figure 1 Figure 3 Figure 6 Shi-1'' Figure 4wA Figure 7

Claims (3)

[Claims] (1) A bottom plate, a top plate on which objects are loaded, a variable volume body disposed between the bottom plate and the top plate, and a fluid discharged as the volume of the variable volume body decreases during loading. a flow restriction means for providing resistance to the flow of the pallet, and the shock energy during loading is absorbed by the variable volume body and the flow restriction means. (2) The variable volume body is connected to a pressure tank, and gas is sealed in the variable volume body and the pressure tank, and when loading, the variable volume body contracts and the gas in the variable volume is transferred to the pressure tank. The device according to claim 1, wherein the impact energy during loading is absorbed. (3) The variable volume body is connected to a pressure tank, the inside of the pressure tank is divided into a gas chamber and a liquid chamber by floating, the variable volume body is connected to the liquid chamber, and the gas chamber of the pressure tank Gas is sealed in the pressure tank, and liquid is sealed in the liquid chamber and variable volume body of the pressure tank. When loading, the variable volume body contracts and the liquid in the variable volume body is discharged into the liquid chamber of the pressure tank. The device according to claim 1, wherein the floating moves to reduce the gas chamber and absorb impact energy during loading.