JPH10218177A - Integrally formed pallet made of synthetic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the flexural strength of a pallet and improve washability of easily removing soil, such as dirt and dust, stuck to ribs of the pallet, by forming hollow ribs extending in a direction orthogonal to a fork insertion hole between a front portion and a rear portion of the pallet. SOLUTION: An integrally formed pallet made of a synthetic resin has a front portion 2 constituted with ribs 1a-1d, a rear portion 4 constituted with ribs 3a-3d, and cylindrical girders 5a, 5b connecting the front portion 2 with the rear portion 4, and has a fork insertion hole 6 formed between the cylindrical girders 5a, 5b. In this pallet, ribs extending in a direction orthogonal to the fork insertion hole 6 between the front portion 2 and the rear portion 4 are formed with the hollow ribs 1a, 3a having hollow portions 7a, 8a, respectively. Further, each portion between the hollow ribs 1a, the hollow ribs 1a and 3a, and the hollow ribs 3a is connected by the solid ribs 1b, 3b, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrally molded synthetic resin pallet used for transporting, moving, and storing various articles.

[0002]

2. Description of the Related Art Conventionally, there has been provided a front part formed by ribs, a back part formed by ribs, and a tubular girder connecting the front part and the back part. The formed integrally molded synthetic resin pallet is used.

[0003]

However, in such an integrally molded synthetic resin pallet, the bending strength is not sufficient when the front and rear portions are formed of I-shaped ribs in cross section. Was. Accordingly, in such an integrally molded synthetic resin pallet, the bending strength was able to be improved to some extent by forming the front and rear portions with U-shaped ribs whose cross sections were opened inward. It was difficult to remove dirt such as dust and dirt attached to the U-shaped rib, and the cleaning property was not good. The present inventors have conducted research on an integrally molded synthetic resin pallet having high bending strength and excellent cleaning properties, and as a result, have reached the present invention.

[0004]

According to the first aspect of the present invention,
It is made of an integrally molded synthetic resin having a front part constituted by ribs, a back part constituted by ribs, and a cylindrical girder connecting the front part and the back part, and a fork insertion hole formed between the cylindrical girder. An integrated synthetic resin pallet, characterized in that hollow ribs extending in a direction perpendicular to the fork insertion holes are formed on the front and rear portions of the pallet. The invention according to claim 2 provides a front surface portion formed by a rib, a back surface portion formed by a rib, and a side tubular girder formed on both sides connecting the front surface portion and the back surface portion, and a tube on both sides. In a single-piece synthetic resin pallet having an intermediate cylindrical girder formed in the middle of the girder and having a fork insertion hole formed between the cylindrical girder, fork insertion holes are formed on the front surface and the back surface. And a hollow rib extending in a direction perpendicular to the pallet. A third aspect of the present invention is a cylindrical girder formed at a front portion formed by a rib, a back portion formed by a rib, and a corner formed at a corner connecting the front portion and the back portion, and one side edge. A tubular girder in the middle part formed in the middle part, a tubular girder in the middle part formed in the middle part of the other side edge, and a tubular girder in the middle part formed in the middle part. An integrated plastic pallet in which fork insertion holes are formed between girders, wherein hollow ribs extending in a direction perpendicular to the fork insertion holes are formed on the front surface and the back surface. It is a molded synthetic resin pallet.

[0005] In these integrally molded synthetic resin pallets, it is preferable to form solid ribs for connecting hollow ribs to the front surface or the back surface. At that time, it is preferable that the width of the hollow rib is larger than the width of the solid rib by 2 mm or more.
It is desirable that the width of the hollow rib is 5 to 40 mm. Further, the width of the hollow rib is preferably 8 to 30 mm. Further, the width of the solid rib is desirably 3 to 7 mm.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, for example, the pallet made of integrally molded synthetic resin of the present invention has a front surface portion 2 constituted by ribs 1a to 1d, a back surface portion 4 constituted by ribs 3a to 3d, and a front surface portion thereof. In a pallet made of an integrally molded synthetic resin having cylindrical girders 5a and b connecting the rear part 2 and the back part 4, and fork insertion holes 6 formed between the cylindrical girders 5a and b, A hollow rib 1a is formed on the portion 2 and the back surface portion 4 so as to extend in a direction orthogonal to the fork insertion hole 6.

A pallet made of integrally molded synthetic resin shown in FIGS. 1 and 2, which is an example of the present invention, has a front surface portion 2 constituted by ribs 1a to 1d, a back surface portion 4 constituted by ribs 3a to 3d, and a front surface portion. The side tubular girder 5a (one of them is not shown) formed on both sides connecting the part 2 and the back surface part 4 and the middle cylindrical body formed in the middle of the cylindrical girder 5a on both sides thereof The fork insertion hole 6 is formed between the cylindrical girder 5a and the cylindrical girder 5b. A rib 1a formed between the side tubular girder 5a and the middle tubular girder 5b.
Is a hollow hollow rib 1 extending in a direction orthogonal to the fork insertion hole 6 and having a hollow portion 7a formed therein.
a. Further, the rib 1b is formed so as to connect the hollow ribs 1a, 1a,..., And the rib 1b is a solid rib 1b which is not hollow.
Similarly, a rib 3a which is a kind of a rib constituting the back surface portion 4
Is a hollow hollow rib 3a extending in a direction orthogonal to the fork insertion hole 6 and having a hollow portion 8a formed therein. Moreover, those hollow ribs 3
a, 3a,.
b is a solid rib 3b which is not hollow.

Further, in the pallet made of an integrally molded synthetic resin in the illustrated example, the surface portion 2 is provided in the tubular girder 5a at the side portion.
Are formed, and the ribs 3c forming the back surface portion 4 are formed at positions where they do not vertically overlap the ribs 1c of the front surface portion 2. Further, the cylindrical girder 5b in the middle portion
Inside, a rib 1d constituting the front surface portion 2 is formed, and a rib 3d constituting the rear surface portion 4 is formed at a position where the rib 3d does not vertically overlap the rib 1d of the front surface portion 2. Further, as shown in FIG. 3, the gas-introducing rib 1 is provided on the tubular girder 5a at the same height as the hollow rib 1a or the hollow rib 3a.
6 and 16 are formed. This gas introduction rib 16,
Reference numeral 16 denotes a hollow member having a hollow portion 17 formed therein. The hollow portion 7a in each hollow rib 1a communicates with the hollow portion 17. Similarly, the hollow portion 8a in each hollow rib 3a also communicates with the hollow portion 17. Further, a gas injection portion 15 is formed on the front surface portion 2 and the back surface portion 4,
This gas injection part 15 and the hollow part 1 in the gas introduction rib 16
7 is in communication.

In order to form this integrally molded synthetic resin pallet, for example, as shown in FIG. 4, the fixed mold 12, the movable mold 13 and the slide core 14 are closed, and molten resin is injected into a predetermined cavity. After the molten resin is filled in the inside, a gas such as nitrogen gas, air, or the like is injected into the molten resin gas injection portion 15, and after cooling the molten resin in the cavity while maintaining the pressure of the injected gas for a predetermined time, fixing is performed. Type 1
2. The movable mold 13 and the slide core 14 may be opened to take out the synthetic resin pallet. Gas injection part 1 for molten resin
When the gas is injected into the cavity 5, the injected gas enters the large gap portion in the cavity, that is, the gas introduction rib 16 having a large width and height, the ribs 1a and 3a having a large width and height, and the like. The gas introduction rib 16 having the hollow portion 17 and the hollow ribs 1a and 3a having the hollow portion therein are formed. However, the injected gas does not enter the narrower rib located before the gas introduction rib 16 and is solid. Ribs 1b and 3b are formed.
Usually, the width and height of the gas introduction rib 16 are preferably about 10 mm. Since the internal pressure of the gas that has entered the hollow ribs 1a and the like acts evenly on the inner wall of the mold portion, the thickness of the formed hollow ribs 1a and the like is almost constant and the thickness is not extremely unevenly distributed. Dimensional fluctuation during molding can be reduced. Further, by forming the hollow portion in the hollow rib 1a or the like in this manner, effects such as a reduction in the weight of the synthetic resin pallet and a reduction in the molding time can be obtained.

The amount of gas injected into the hollow reinforcing ribs 1a and the like during injection molding is adjusted according to the required strength of a synthetic resin pallet 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. The injection molding conditions may be ordinary conditions. For example, when high-density polyethylene is used as a material, the melting temperature (cylinder temperature) is 200 to 250 ° C., and the injection rate is 2000 to 5000 cc.
/ Sec is preferable. In addition, polyethylene, polypropylene,
Polyolefins such as ethylene-propylene copolymers are generally used, but it goes without saying that other synthetic 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. Further, a commonly used organic or inorganic foaming agent may be mixed into these synthetic resins to form a foam. In this case, the expansion ratio is preferably about 1.05 to 1.4 times. In this case, it is preferable that the apparent density of the entire pallet is about 0.65 to 0.9 of the density of the raw material synthetic resin.

The pallet made of an integrally molded synthetic resin according to the present invention is not limited to the above-described illustrated example, and may be, for example, a pallet made of an integrally molded synthetic resin as shown in FIGS. This integrally molded synthetic resin pallet has a front surface portion 2 constituted by ribs 1e to 1n, a back surface portion 4 constituted by ribs 3e to 3l, and a front surface portion 2.
5c at the corner formed at the corner connecting the back side 4 and the middle part 5d at the middle of one side edge, and 5d at the middle of the other side edge. And a central tubular girder 5f formed at the center and a fork insertion hole 6 formed between the tubular girder 5c, 5d, 5e and 5f. I have. In the pallet made of an integrally molded synthetic resin of the illustrated example, a rib 1 constituting the surface portion 2 is provided between the cylindrical girder 5c at the corner and the cylindrical girder 5d at the middle.
e, 1e are formed to extend in a direction orthogonal to the fork insertion hole 6, and the rib 1e has a hollow shape having a hollow portion 7b therein. The rib 1f formed so as to connect the hollow ribs 1e is a solid rib 1f that is not hollow.

A plate-like portion 9 is formed on the back surface portion 4, and a hollow rib 3e having a hollow portion 8b inside the plate-like portion 9 and extending in a direction orthogonal to the fork insertion hole 6.
Are formed. Further, between the cylindrical girder 5c at the corner and the cylindrical girder 5e at the middle, a rib 1g constituting the surface portion 2 is provided.
Is formed to extend in a direction orthogonal to the fork insertion hole 6,
The rib 1g has a hollow shape having a hollow portion 7c therein. Further, a solid rib 1h which is not hollow is formed so as to connect the hollow rib 1g. Further, a plate-like portion 10 is formed on the back surface portion 4, and a hollow rib 3f having a hollow portion 8c is formed below the plate-like portion 10 and extends in a direction orthogonal to the fork insertion hole. In this integrally molded synthetic resin pallet, a hollow portion 7 is provided between the middle tubular girder 5e and the central tubular girder 5f.
A hollow rib 1i that is hollow and has a surface portion 2 and has a d is formed. The hollow rib 3g constituting the back surface portion 4 is formed in a hollow shape having a hollow portion 8d therein at a position not vertically overlapping the hollow rib 1i of the front surface portion 2.

The pallet made of integrally molded synthetic resin has a hollow portion 7e inside the surface portion 2 between the tubular portion 5d at the intermediate portion and the tubular portion 5f at the central portion. A hollow rib 1j is formed. Further, a hollow rib 3h constituting a back surface portion 4 and having a hollow portion 8e therein is formed at a position on the front surface portion 2 which does not vertically overlap with the hollow rib 1j. Further, in this integrally molded synthetic resin pallet, a rib 1k forming the front surface portion 2 is formed in the cylindrical girder 5c at the corner portion, and the front surface portion 2 forming the back surface portion 4 is formed.
The rib 3i is formed at a position where the rib 3i does not vertically overlap with the rib 1k. Further, a rib 11 constituting the front surface portion 2 is formed in the middle tubular girder 5d, and a rib 3j is provided at a position which does not vertically overlap the rib 11 of the front surface portion 2 constituting the back surface portion 4. Is formed. Further, a rib 1m constituting the front surface portion 2 is formed in the middle tubular girder 5e, and a rib 3k is formed at a position which does not vertically overlap the rib 1m of the front surface portion 2 constituting the back surface portion 4. Have been. Further, a rib 1n is formed as a rib 1 constituting the front surface portion 2 in the central tubular girder 5f, and the rear surface portion 4 is formed.
Is formed at a position where the rib 3n does not vertically overlap the rib 1n of the surface portion 2. Also,
At the intersection of the fork insertion hole 6, the grid-like rib 1
1 is formed. Further, as shown in FIGS.
Gas introduction ribs 16 are formed on the tubular girders 5d and 5f, and the gas introduction ribs 16 are hollow with a hollow portion 17 formed therein. The hollow portions 7b to 8e and the hollow portions 8b to 8e formed in the respective hollow ribs communicate with the hollow portion 17. The gas introduction rib 16
The hollow portion 17 communicates with the gas injection portions 15 formed on the front surface portion 2 and the back surface portion 4 respectively.

This integrally molded synthetic resin pallet can be molded in the same manner as the synthetic resin pallet shown in FIG. 1 described above. For example, as shown in FIG.
Close the fixed mold 12, the movable mold 13 and the slide core 14,
After the molten resin is injected into the cavity and the cavity is filled with the molten resin, a gas such as nitrogen gas or air is injected into the gas injection portion 15 of the molten resin, and while maintaining the pressure of the injected gas for a predetermined time, the cavity is maintained. After cooling the molten resin inside, the fixed mold 12, the movable mold 13 and the slide core 14 are opened and the synthetic resin pallet may be taken out. When the gas is injected into the gas injection portion 15 of the molten resin, the injected gas is filled with a portion having a large void in the cavity, that is, a gas introduction rib 16 having a large width and height, a rib 1e having a large width and height, and 3e.
e, 1g, 3f, 1i, 3g, 1j, 3h, etc.
A gas introduction rib 16 having a hollow portion 17 therein and a hollow rib 1e, 3e, 1g, 3f, 1 having a hollow portion therein.
Although i, 3g, 1j, and 3h are formed, solid ribs 1f and 1h are formed because the injected gas does not enter the narrower rib before the gas.

In the pallets made of integrally molded synthetic resin according to the present invention, the hollow ribs 1a, 3a, 1e,
It is preferable that the widths of e, 1g, 3f, 1i, 3g, 1j, and 3h be at least 2 mm larger than the widths of the solid ribs 1b, 3b, 1f, and 1h. Usually, hollow ribs 1a, 3a, 1
The width of e, 3e, 1g, 3f, 1i, 3g, 1j, 3h is preferably 5 to 40 mm, more preferably 8 to 30 mm, and the width of the solid ribs 1b, 3b, 1f, 1h is 3 to 40 mm. It is preferably 7 mm. In the pallet made of an integrally molded synthetic resin according to the present invention, the hollow ribs 1a,
3a, 1e, 3e, 1g, 3f, 1i, 3g, 1j, 3
h and the height of the solid ribs 1b, 3b, 1f, 1h are 20 to
Preferably, the thickness of the tubular girder 5 is 3 to 40 mm.
It is preferably 7 mm. In the illustrated integrally molded synthetic resin pallet, solid ribs 1b, 3b, 1f, and 1h are formed along the fork insertion holes, but hollow ribs having hollow portions therein as necessary. May be formed.

[0016]

The pallet made of integrally molded synthetic resin according to the present invention has a large bending strength and excellent cleanability by forming hollow ribs extending in the direction perpendicular to the fork insertion holes on the front and rear portions. ing.

[Brief description of the drawings]

FIG. 1 shows an example of a pallet made of integrally molded synthetic resin according to the present invention. FIG. 1 (a) is a plan view of a quarter thereof, and FIG. 1 (b) is a side view thereof.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a sectional view taken along the line BB in FIG.

FIG. 4 is a partial cross-sectional view for explaining a method of forming the integrally molded synthetic resin pallet shown in FIG.

FIG. 5 (a) shows another example of an integrally molded synthetic resin pallet, and FIG. 5 (a) is a plan view of a quarter portion, FIG.
FIG. 5B is a side view, and FIG. 5C is a side view from the other side.

FIG. 6 is a bottom view of a quarter of the integrally molded synthetic resin pallet shown in FIG. 5;

FIG. 7 is a sectional view taken along the line CC in FIG. 5;

8 is a sectional view taken along the line DD in FIG. 5;

FIG. 9 is a sectional view taken along the line EE in FIG. 5;

FIG. 10 is a partial cross-sectional view for explaining a method of forming the integrally molded synthetic resin pallet shown in FIG.

[Explanation of symbols]

 1a, 1e, 1g, 1i, 1j Hollow rib 1b, 1f, 1h Solid rib 2 Surface 3a, 3e, 3f, 3g, 3h Hollow rib 3b Solid rib 4 Back 5a, 5b, 5c, 5d, 5e 5f Cylindrical girder 6 Fork insertion hole

Continued on the front page (72) Inventor Tsutomu Nakayama 2412-9 Fujisan, Ueda-shi, Nagano Japan Palette Tech Co., Ltd. (72) Inventor Rei Isodo 2-5-2-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Chemical Corporation Functional Materials In company

Claims (8)

[Claims] A front part formed by the rib, a back part formed by the rib, and a cylindrical girder connecting the front part and the back part, and a fork insertion hole is formed between the cylindrical girder. An integrally molded synthetic resin pallet, wherein a hollow rib extending in a direction orthogonal to a fork insertion hole is formed on a front surface portion and a rear surface portion. 2. A front part formed by ribs, a back part formed by ribs, and a side tubular girder formed on both sides connecting the front part and the back part, and a cylindrical girder on both sides. In an integrally molded synthetic resin pallet having an intermediate cylindrical girder formed in the middle and having a fork insertion hole formed between the cylindrical girder, the front and back surfaces are orthogonal to the fork insertion hole. An integrally molded synthetic resin pallet, wherein a hollow rib extending in a direction is formed. 3. A front surface part constituted by a rib, a back part constituted by a rib, a cylindrical girder formed at a corner connecting the front part and the back part, and an intermediate part of one side edge. A middle part cylindrical girder formed in the middle part of the middle part formed in the middle part of the other side edge, and a center part girder formed in the center part. An integrated molded synthetic resin pallet having a fork insertion hole formed therein, wherein a hollow rib extending in a direction perpendicular to the fork insertion hole is formed on a front surface portion and a back surface portion. Pallets. 4. The pallet made of an integrally molded synthetic resin according to claim 1, wherein a solid rib for connecting a hollow rib is formed on a front surface portion or a rear surface portion. 5. The width of the hollow rib is 2 m larger than the width of the solid rib.
The pallet made of an integrally molded synthetic resin according to claim 4, which is larger than m. 6. The integrally molded synthetic resin pallet according to claim 1, wherein the width of the hollow rib is 5 to 40 mm. 7. The pallet made of an integrally molded synthetic resin according to claim 1, wherein the width of the hollow rib is 8 to 30 mm. 8. The integrally molded synthetic resin pallet according to claim 4, wherein the width of the solid rib is 3 to 7 mm.