DECK PLATE

Description

TECHNICAL FIELD

The present invention relates to a deck plate.

BACKGROUND ART

To construct a floor slab, a roof, and a rooftop slab of a building structure, a deck plate is widely used. The deck plate is disposed to be bridged between beams, and both ends of the deck plate are fixed to upper surfaces of the beams. After the deck plate is fixed, concrete is placed on the deck plate. When the concrete is solidified, a floor structure, a roof, or a rooftop structure is constructed.

The deck plate is formed by bending a metal plate by roll forming or the like. Ribs for enhancing rigidity are provided on the deck plate, and protruding streak portions protruding toward the ribs are provided on slab supporting portions provided between the ribs (for example, see Patent Literature 1).

DOCUMENT LIST

Patent Literature

• Patent Literature 1: Japanese Patent Application Publication No. 2017-150132

SUMMARY OF INVENTION

Technical Problem

After being manufactured in a factory, a predetermined number of deck plates as described above are tied with a band and shipped. The deck plates include the ribs. Therefore, when the deck plates are stacked in the same direction, a volume is increased, and the number of deck plates to be stacked is limited. Therefore, deck plates in a pair are stacked while being turned upside down relative to each other, and a plurality of pairs of stacked deck plates are stacked and tied with the band (hereinafter, referred to as package).

However, when deck plates 200 and 300 in a pair are stacked as illustrated in FIG. 8, ribs 201 of one deck plate 200 contact recessed streak portions 302 of the other deck plate 300, and ribs 301 of the other deck plate 300 contact recessed streak portions 202 of the one deck plate 200 in some cases. In this case, contact areas between the ribs 201 and the recessed streak portions 302 and contact areas between the ribs 301 and the recessed streak portions 202 are small to cause an unstable state. When the deck plates 200 and 300 are tied with a band 400, the deck plate 200 and 300 are bent with contact parts as fulcrums. In addition, the whole of the package is in an unstable shape. Thus, the package does not stand by itself and easily falls over.

It is an object of the present invention, which has been made in consideration of the above-described problem, to provide a technique for stacking deck plates in a stable state.

Solution to Problem

To solve the above-described problem, according to an aspect of the present invention, a deck plate is formed of a metal plate and includes plane portions and ribs provided alternately and continuously. Bottom surfaces of the ribs and contact parts of the plane portions contacting the bottom surfaces of the ribs when deck plates in a pair are stacked while being turned upside down relative to each other are formed in complementary shapes.

The bottom surfaces of the ribs and the contact parts are each preferably formed in a plane shape.

When the deck plates in a pair are stacked while being turned upside down relative to each other, the entire bottom surfaces of the ribs preferably contact the contact parts.

Each of the plane portions preferably includes protruding streak portions protruding toward one of surfaces. The bottom surfaces of the ribs contacting the protruding streak portions when the deck plates in a pair are stacked while being turned upside down relative to each other are preferably formed in shapes complementary to the protruding streak portions.

When the deck plates in a pair are stacked while being turned upside down relative to each other, the entire bottom surfaces of the ribs preferably contact the protruding streak portions.

Each of the plane portions preferably includes protruding streak portions protruding toward one of surfaces. The protruding streak portions contacting each other when a plurality of pairs of deck plates stacked while being turned upside down relative to each other are stacked are preferably formed in complementary shapes.

When the plurality of pairs of deck plates stacked while being turned upside down relative to each other are stacked, entire regions of the protruding streak portions of one deck plate preferably contact the protruding streak portions of another deck plate.

The protruding streak portions preferably include first protruding streak portions protruding toward a surface on which the ribs are provided on the plane portions, and second protruding streak portions protruding toward a surface opposite to the surface on which the ribs are provided on the plane portions.

The deck plates in a pair are preferably stacked while being turned upside down relative to each other, to minimize a height and a width in a transverse direction.

Effects of Invention

According to the aspect of the present invention, it is possible to stack the deck plates in the stable state.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 A perspective view of a deck plate according to a first embodiment.

FIG. 2 A cross-sectional view taken along line A-A of the deck plate illustrated in FIG. 1.

FIG. 3 An enlarged cross-sectional view of a protruding streak portion illustrated in FIG. 2.

FIG. 4 A cross-sectional view illustrating a state where the deck plates illustrated in FIG. 1 are stacked.

FIG. 5 A perspective view of a deck plate according to a second embodiment.

FIG. 6 A cross-sectional view taken along line B-B of the deck plate illustrated in FIG. 5.

FIG. 7 A cross-sectional view illustrating a state where the deck plates illustrated in FIG. 5 are stacked.

FIG. 8 A view for explaining an issue when existing deck plates are stacked and tied.

DESCRIPTION OF EMBODIMENTS

Some embodiments of the present invention are described below with reference to drawings. In the following description, the drawings are schematic, and it should be noted that a relationship between dimensions of elements, ratios of the elements, and the like are different from actual ones. The size relationship or ratio may also be partly different among the drawings.

First Embodiment

A configuration of a deck plate according to a first embodiment is described with reference to FIG. 1 to FIG. 4. FIG. 1 is a perspective view of the deck plate. FIG. 2 is a cross-sectional view taken along line A-A of the deck plate illustrated in FIG. 1. FIG. 3 is an enlarged cross-sectional view of a protruding streak portion illustrated in FIG. 2. FIG. 4 is a cross-sectional view illustrating a state where the deck plates illustrated in FIG. 1 are stacked.

As illustrated in FIG. 1 to FIG. 4, a deck plate 10 serves as a form for concrete placed to construct a floor structure (or roof or rooftop structure) of a building structure.

<Configuration of Deck Plate>

As illustrated in FIG. 1, the deck plate 10 is bridged between beams facing each other. One end of the deck plate 10 is placed on one of the beams and is fixed to the beam by welding or the like, and another end is placed on the other beam and is fixed to the other beam by welding or the like. More specifically, the beams are each made of, for example, an H-section steel, and the ends of the deck plate 10 are placed on and fixed to flange portions of the H-section steels forming the respective beams.

As illustrated in FIG. 1 and FIG. 2, the deck plate 10 is formed of a thin steel plate subjected to or not subjected to surface treatment such as galvanization. The deck plate 10 is manufactured by, for example, roll-forming a flat steel plate by a roll forming machine. The deck plate 10 is bent at a plurality of positions by the roll forming machine. The deck plate 10 preferably has a thickness of 0.6 mm to 2.3 mm.

The deck plate 10 includes, for example, two ribs 1 and 2, plane portions 3, protruding streak portions 4, a locked portion 5, and end-closed portions 6.

(Rib)

As illustrated in FIG. 2, the rib 1 is formed by bending the steel plate. The rib 1 includes a bent part 11 bent toward one of surfaces of the steel plate, a straight part 12 that is continuous from the bent part 11 and in which a surface direction extends in a direction orthogonal to the plane portions 3, a folded-back part 13 that is continuous from the straight part 12 and is folded back by being bent a plurality of times, a straight part 14 that is continuous from the folded-back part 13 and in which a surface direction extends along the straight part 12, and a bent part 15 that is continuous from the straight part 14 and is bent toward the plane portions 3.

Each of the bent part 11 and the bent part 15 is formed such that a bending radius R is about 3 mm to about 10 mm, for example, about 6 mm. This is because bending processing by roll forming is relatively easily performable, and to prevent a recess formed between the bent parts 11 and 15 from being increased more than necessary to cause a waste of concrete.

The straight part 12 and the straight part 14 are formed such that a surface of the straight part 12 and a surface of the straight part 14 contact each other, and are coupled by swaging or the like. This prevents the straight part 12 and the straight part 14 from separating from each other.

The folded-back part 13 is formed to have a substantially triangular shape in a cross-sectional view, and is folded back such that a start point and an end point are adjacent to each other and the straight part 12 and the straight part 14 contact each other. The folded-back part 13 is formed such that a bottom surface part 13b corresponding to a bottom surface of the rib 1 has one flat plane.

As illustrated in FIG. 2, the rib 2 is formed by bending the steel plate. The rib 2 includes a bent part 21 bent toward one of surfaces of the steel plate, a straight part 22 that is continuous from the bent part 21 and in which a surface direction extends in the direction orthogonal to the plane portions 3, a folded-back part 23 that is continuous from the straight part 22 and is folded back by being bent a plurality of times, a straight part 24 that is continuous from the folded-back part 23 and in which a surface direction extends along the straight part 22, an inclined part 25 that is continuous from the straight part 24 and is obliquely inclined toward the plane portions 3 in a direction separating from the straight part 22, a straight part 26 that is continuous from the inclined part 25 and in which a surface direction extends along the straight part 22, and a bent part 27 that is continuous from the straight part 26 and is bent toward the plane portions 3.

Each of the bent part 21 and the bent part 27 is formed such that a bending radius R is about 3 mm to about 10 mm, for example, about 6 mm. This is because bending processing by roll forming is relatively easily performable, and to prevent a recess formed between the bent parts 21 and 27 from being increased more than necessary to cause a waste of concrete.

The straight part 22 and the straight part 24 are formed such that a surface of the straight part 22 and a surface of the straight part 24 contact each other, and are coupled by swaging or the like. This prevents the straight part 22 and the straight part 24 from separating from each other.

The folded-back part 23 is formed to have a substantially triangular shape in a cross-sectional view, and is folded back such that a start point and an end point are adjacent to each other and the straight part 22 and straight part 24 contact each other. The folded-back part 23 is formed such that a bottom surface part 23b corresponding to a bottom surface of the rib 2 has one flat plane. The bottom surface part 23b of the folded-back part 23 is formed to be positioned on the plane same as the bottom surface part 13b of the folded-back part 13.

The inclined part 25 is to form a gap between the straight part 22 and the straight part 26. The inclined part 25 enables insertion of the locked portion 5 with the gap formed between the straight part 22 and the straight part 26 as a reception portion 50 for the locked portion 5.

The deck plate 10 includes, for example, the two ribs 1 and 2. The rib 1 and the rib 2 are provided with an interval (distance between centers) of 180 mm to 220 mm along a width direction (transverse direction) of the deck plate 10. More specifically, a length L of the deck plate 10 in the width direction is 360 mm to 440 mm. The rib 1 is provided such that a distance L1 from one end of the deck plate 10 in the width direction to a center of the rib 1 (center of rib 1 is boundary surface on which straight part 12 and straight part 14 contact each other) becomes 180 mm to 220 mm. The rib 2 is provided such that a distance L2 from the center of the rib 1 to a center of the rib 2 (center of rib 2 is boundary surface on which straight part 22 and straight part 24 contact each other) becomes 180 mm to 220 mm. In other words, the rib 1 is provided near a center of the deck plate 10 in the width direction, and the rib 2 is provided near an end of the deck plate 10 in the width direction. The distance L1 and the distance L2 are preferably equal to each other, and for example, each of the distances L1 and L2 is 200 mm, and the length L is 400 mm.

The ribs 1 and 2 are provided to extend along a length direction (longitudinal direction) of the deck plate 10. In other words, the ribs 1 and 2 are provided continuously from the one end to the other end along a direction in which the deck plate 10 is bridged between beams 20.

Each of the ribs 1 and 2 is preferably formed such that a height H from a lower end to an upper end (upper surface) of each plane portion 3 is 50 mm to 150 mm, and is formed, for example, such that the height H is 100 mm.

(Plane Portion)

As illustrated in FIG. 2, the plane portions 3 are mainly portions where the ribs 1 and 2 are not provided in the deck plate 10, and are planes mainly receiving a load of the placed concrete. The plane portions 3 are provided adjacent to the ribs 1 and 2 in the transverse direction of the deck plate 10. In other words, in the deck plate 10, the ribs 1 and 2 and the plane portions 3 are alternately provided. In the deck plate 10, the plane portions 3 are provided on the same plane.

As illustrated in FIG. 4, deck plates 10a and 10b in a pair are stacked while being turned upside down relative to each other so as to minimize a height and a width in the transverse direction by bringing the rib 1 of the deck plate 10a and the rib 1 of the deck plate 10b close to each other as much as possible (for example, until any portions of deck plates 10a and 10b contact each other). Contact parts 3a and 3b of the plane portions 3 (surfaces of plane portions on rib side) of one of the deck plates contacting the bottom surface parts 13b and 23b of the ribs 1 and 2 of the other deck plate at that time are formed in shapes complementary to the bottom surface parts 13b and 23b of the ribs 1 and 2. More specifically, as illustrated in FIG. 2 and FIG. 4, since the bottom surface parts 13b and 23b of the ribs 1 and 2 are each formed in one flat plane shape, the contact parts 3a and 3b are also each formed in a plane shape having one flat surface. The contact parts 3a and 3b are provided on the plane same as the plane portions 3. In other words, the contact parts 3a and 3b are parts where no protruding streak portions 4 are provided. Therefore, when the deck plates 10a and 10b in a pair are stacked while being turned upside down relative to each other so as to minimize the height and the width in the transverse direction, the entire bottom surface parts 13b and 23b of the ribs 1 and 2 of the one deck plate contact the contact parts 3a and 3b of the plane portions 3 of the other deck plate. At this time, the surface direction of the bottom surface parts 13b and 23b of the ribs 1 and 2 and the surface direction of the contact parts 3a and 3b of the plane portions 3 are parallel to each other, and are present on the substantially same plane along the transverse direction of the deck plate 10.

(Protruding Streak Portion)

As illustrated in FIG. 2, each of the protruding streak portions 4 is formed by bending the steel plate. The protruding streak portions 4 are formed to protrude toward the surfaces of the plane portions 3 on which the ribs 1 and 2 are provided. Thus, the plane portions 3 are planes in which flat parts and valley parts (ridge parts as viewed from opposite side) are alternately continued.

The plurality of protruding streak portions 4 are provided side by side along the transverse direction of the deck plate 10. For example, two protruding streak portions 4 are provided on each of the plane portions 3. Depending on a width of each of the protruding streak portions 4, for example, the number of protruding streak portions 4 is preferably 1 to 5 on each of the plane portions 3. The protruding streak portions 4 are provided to extend along the longitudinal direction of the deck plate 10.

As illustrated in FIG. 3, each of the protruding streak portions 4 is preferably formed such that a width B along the transverse direction of the deck plate 10 is 20 mm to 30 mm, a height h (length from lower surface of each plane portion 3 to outer surface of portion most protruding from rings 1 and 2 side) is 3 mm to 8 mm. Each of the protruding streak portions 4 is formed such that a valley part 41 formed at a center in the width direction is deepest, and includes inclined surfaces 42 having the same inclination on both dies of the valley part 41 in the width direction. Each of the protruding streak portions 4 is preferably formed such that a bending radius R of each of bent parts 43 (boundary parts with respective plane portions 3 and valley part) at which a metal plate is bent is 3 mm to 6 mm.

(Locked Portion)

The locked portion 5 is provided at one end of the deck plate 10. The locked portion 5 is an end part of the steel material bent at a substantially right angle from the adjacent plane portion 3, and is provided to extend along the height direction of the ribs 1 and 2. When the deck plates 10 are coupled, the locked portion 5 of one of the deck plates 10 is inserted into the reception portion 50 provided on the rib 2 of the other deck plate 10. When the deck plates 10 are coupled, the deck plates 10 are superimposed such that a part of the plane portions 3 of the one deck plate 10 is placed on an upper surface of an extending portion 8 of the other deck plate 10, and the locked portion 5 of the one deck plate 10 is inserted into the reception portion 50 of the other deck plate 10. The extending portion 8 is provided continuously from the bent part 27 of the rib 2 and extends along the plane portions 3.

It is sufficient for the locked portion 5 to have a height enough to be locked to the reception portion 50. Further, based on the premise that leakage of the placed concrete is prevented, the deck plates 10 may be coupled by superimposition of the plane portions, joining by welding, or fastening tools such as screws, without forming the locked portion 5.

Further, it is sufficient for the reception portion 50 to receive the locked portion 5.

(End-Closed Portion)

As illustrated in FIG. 1, the end-closed portions 6 are provided at both ends of the deck plate 10 in the length direction (longitudinal direction). The end-closed portions 6 are formed by crushing both ends of the rib 1 and the rib 2 in a direction orthogonal to the surface of the deck plate 10. Thus, in the rib 1 and the rib 2, the end-closed portions 6 at the both ends are each formed to have a crushed cross-section, and the other portions sandwiched between the end-closed portions 6 are each formed to have a substantially triangular shape in a cross-sectional view. As a result, the both ends of the rib 1 and the rib 2 are lower in height than the other portions, and accordingly the both ends of the rib 1 and rib 2 can be placed on upper surfaces of the flange portions of the beams. Each of the end-closed portions 6 is formed to have a length along the extending direction of the rib 1 and the rib 2 greater than a length placed on the upper surface of the flange portion of the corresponding beam.

<Stacking of Deck Plates>

When the manufactured deck plate 10 is shipped, a plurality of pairs of stacked deck plates 10a and 10b are stacked and tied with a band to form a package.

FIG. 4 is a cross-sectional view illustrating a state where the deck plates 10a and 10b in a pair are stacked while being turned upside down relative to each other so as to minimize the height and the width in the transverse direction.

In the state illustrated in FIG. 4, one deck plate 10a is disposed such that the ribs 1 and 2 are directed downward, whereas the other deck plate 10b is disposed such that the ribs 1 and 2 are directed upward. The deck plates 10a and 10b in a pair are stacked while being turned upside down relative to each other so as to minimize the height and the width in the transverse direction by bringing the rib 1 of the deck plate 10a and the rib 1 of the deck plate 10b close to each other as much as possible (for example, until any portions of deck plates 10a and 10b contact each other).

The bottom surface part 23b of the rib 2 of the other deck plate 10b is in surface contact with the contact part 3a of the one deck plate 10a, and the bottom surface part 13b of the rib 1 of the other deck plate 10b is in surface contact with the contact part 3b of the one deck plate 10a.

The bottom surface part 23b of the rib 2 of the one deck plate 10a is in surface contact with the contact part 3a of the one deck plate 10b, and the bottom surface part 13b of the rib 1 of the one deck plate 10a is in surface contact with the contact part 3b of the other deck plate 10b.

In the state illustrated in FIG. 4, the contact areas of the plane portions 3 and the ribs 1 and 2 of the deck plates 10a and 10b in a pair are large, and the heights of the deck plates 10a and 10b in a pair are equal to each other. Thus, a stable state is established.

According to the above-described deck plate 10, when the deck plates 10a and 10b in a pair are stacked while being turned upside down relative to each other so as to minimize the height and the width in the transverse direction, the contact areas of the bottom surfaces of the ribs 1 and 2 and the contact parts 3a and 3b can be maximally secured because the bottom surfaces of the ribs 1 and 2 and the contact parts 3a and 3b of the plane portions 3 contacting the bottom surfaces of the ribs 1 and 2 are formed in complementary shapes. Further, the heights at respective positions when the deck plates 10a and 10b in a pair are stacked are equal to one another, and the deck plates 10 can be stacked in the stable state. Therefore, when the plurality of pairs of stacked deck plates 10a and 10b are stacked and tied with the band to form the package, a fulcrum at which the ends of the deck plates 10a and 10b in the transverse direction are bent by the band does not occur. Thus, the deck plates 10a and 10b are not floated, and are prevented from being bent. This makes it possible to ship the deck plates 10a and 10b in a state where quality of products is maintained, and to secure stability of the package.

Further, the bottom surface parts 13b and 23b of the ribs 1 and 2 and the contact parts 3a and 3b are formed in planar complementary shapes. This makes it possible to enhance stability when the deck plates 10a and 10b in a pair are stacked. In addition, it is unnecessary to perform processing for formation of the contact parts 3a and 3b. Thus, a manufacturing step is not complicated.

Second Embodiment

A configuration of a deck plate according to a second embodiment is described with reference to FIG. 5 to FIG. 7. FIG. 5 is a perspective view of the deck plate. FIG. 6 is a cross-sectional view taken along line B-B of the deck plate illustrated in FIG. 5. FIG. 7 is a cross-sectional view illustrating a state where the deck plates illustrated in FIG. 5 are stacked. The deck plate according to the second embodiment is different in configurations of the ribs and the protruding streak portions from the deck plate according to the first embodiment. Therefore, in the following, differences are mainly described in detail, and common components are described while being denoted by the same reference numerals.

<Configuration of Deck Plate>

As illustrated in FIG. 5 and FIG. 6, a deck plate 70 is formed of a thin steel plate subjected to or not subjected to surface treatment such as galvanization. The deck plate 70 includes, for example, two ribs 1a and 2a, the plane portions 3, the protruding streak portions 4, the locked portion 5, and the end-closed portions 6.

(Rib)

As illustrated in FIG. 6, the rib 1a is formed by bending the steel plate. The rib 1a includes the bent part 11 bent toward one of surfaces of the steel plate, the straight part 12 that is continuous from the bent part 11 and in which a surface direction extends in the direction orthogonal to the plane portions 3, the folded-back part 13 that is continuous from the straight part 12 and is folded back by being bent a plurality of times, the straight part 14 that is continuous from the folded-back part 13 and in which a surface direction extends along the straight part 12, and the bent part 15 that is continuous from the straight part 14 and is bent toward the plane portions 3.

The folded-back part 13 is formed to have a substantially triangular shape in a cross-sectional view, and is folded back such that a start point and an end point are adjacent to each other and the straight part 12 and the straight part 14 contact each other. In the folded-back part 13, the bottom surface part 13b corresponding to a bottom surface of the rib 1a is formed in a shape complementary to one of the protruding streak portions 4. More specifically, the bottom surface part 13b includes a recessed part 13c recessed toward inside of the rib 1a. When deck plates 70 in a pair are stacked while being turned upside down relative to each other, a first protruding streak portion 4a (described below) is fitted into the recessed part 13c, and a bottom surface of the recessed part 13c and a protruding surface of the protruding streak portion 4a come into surface contact with each other over substantially the entire regions. In other words, the recessed part 13c and the first protruding streak portion 4a are formed in complementary shapes.

As illustrated in FIG. 6, the rib 2a is formed by bending the steel plate. The rib 2a includes the bent part 21 bent toward one of surfaces of the steel plate, the straight part 22 that is continuous from the bent part 21 and in which a surface direction extends in the direction orthogonal to the plane portions 3, the folded-back part 23 that is continuous from the straight part 22 and is folded back by being bent a plurality of times, the straight part 24 that is continuous from the folded-back part 23 and in which a surface direction extends along the straight part 22, the inclined part 25 that is continuous from the straight part 24 and is obliquely inclined toward the plane portions 3 in a direction separating from the straight part 22, the straight part 26 that is continuous from the inclined part 25 and in which a surface direction extends along the straight part 22, and the bent part 27 that is continuous from the straight part 26 and is bent toward the plane portions 3.

The folded-back part 23 is formed to have a substantially triangular shape in a cross-sectional view, and is folded back such that a start point and an end point are adjacent to each other and the straight part 22 and straight part 24 contact each other. In the folded-back part 23, the bottom surface part 23b corresponding to a bottom surface of the rib 2a is formed in a shape complementary to one of the protruding streak portions 4. More specifically, the bottom surface part 23b includes a recessed part 23c recessed toward inside of the rib 2a. When the deck plates 70 in a pair are stacked while being turned upside down relative to each other, the first protruding streak portion 4a is fitted into the recessed part 23c, and a bottom surface of the recessed part 23c and a protruding surface of the protruding streak portion 4a come into surface contact with each other over substantially the entire region. In other words, the recessed part 23c and the first protruding streak portion 4a are formed in complementary shapes. The bottom surface part 23b of the folded-back part 23 is formed to be positioned on the plane same as the bottom surface part 13b of the folded-back part 13.

(Plane Portion)

As illustrated in FIG. 6, the plane portions 3 are mainly portions where the ribs 1a and 2a are not provided in the deck plate 70, and are planes mainly receiving a load of the placed concrete. The plane portions 3 are provided adjacent to the ribs 1a and 2a in the transverse direction of the deck plate 70. In other words, in the deck plate 70, the ribs 1a and 2a and the plane portions 3 are alternately provided. In the deck plate 70, the plane portions 3 are provided on the same plane.

As illustrated in FIG. 7, the first protruding streak portions 4a are provided on the contact parts 3a and 3b of the plane portions 3 (surfaces of plane portions 3 on rib side) of one of the deck plates contacting the bottom surface parts 13b and 23b of the ribs 1a and 2a of the other deck plate when deck plates 70a and 70b in a pair are stacked while being turned upside down relative to each other. In other words, the first protruding streak portions 4a on the plane portions 3 function as the contact parts 3a and 3b.

(Protruding Streak Portion)

As illustrated in FIG. 6, each of the protruding streak portions 4 is formed by bending the steel plate. The protruding streak portions 4 includes the first protruding streak portions 4a formed to protrude toward the surfaces of the plane portions 3 on which the ribs 1a and 2a are provided, and second protruding streak portions 4b formed to protrude toward surfaces on a side opposite to the surfaces on which the ribs 1a and 2a are provided.

The plurality of protruding streak portions 4 are provided side by side along the width direction of the deck plate 70. For example, three protruding streak portions 4 are formed on each of the plane portions 3. Among the three protruding streak portions 4, two protruding streak portions 4 are formed as the first protruding streak portions 4a, and one protruding streak portion 4 is formed as the second protruding streak portion 4b. Depending on a width of each of the protruding streak portions 4, for example, the number of protruding streak portions 4 is preferably 1 to 5 on each of the plane portions 3. The protruding streak portions 4 are provided to extend along the longitudinal direction of the deck plate 70.

Although the second protruding streak portion 4b may be formed to have a size same as a size of each of the first protruding streak portions 4a, the second protruding streak portion 4b may be formed such that a width and a depth are slightly smaller than a width and a depth of each of the first protruding streak portions 4a in order to be fitted into any of the first protruding streak portions 4a.

As illustrated in FIG. 7, the second protruding streak portions 4b are provided at positions opposed to, when a plurality of pairs of deck plates 70 stacked while being turned upside down relative to each other are stacked, the first protruding streak portions 4a of one deck plate 70a of the deck plates 70 contacting each other. More specifically, as illustrated in FIG. 6 and FIG. 7, the first protruding streak portions 4a and the second protruding streak portion 4b are formed in complementary shapes. The second protruding streak portions 4b of the deck plates 70a and 70b on one side are fitted into the first protruding streak portions 4a of the deck plates 70b and 70a on another side, and the bottom surfaces of the first protruding streak portions 4a and the protruding surfaces of the second protruding streak portions 4b come into surface contact with each other over substantially the entire regions.

<Stacking of Deck Plates>

When the manufactured deck plate 70 is shipped, a plurality of pairs of stacked deck plates 70a and 70b are stacked and tied with a band to form a package.

FIG. 7 is a cross-sectional view illustrating a state where two pairs of deck plates 70a and 70b stacked while being turned upside down relative to each other are stacked.

In the state illustrated in FIG. 7, one deck plate 70a of each pair is disposed such that the ribs 1a and 2a are directed downward, whereas the other deck plate 70b of each pair is disposed such that the ribs 1a and 2a are directed upward. The deck plates 70a and 70b in a pair are stacked in a positioned state by fitting the first protruding streak portions 4a of the deck plate 70a into the recessed parts 13c and 23c of the ribs 1a and 2a of the deck plate 70b.

The first protruding streak portion 4a is provided on the contact part 3a of the one deck plate 70a of each pair, and the recessed part 23c provided on the bottom surface part 23b of the rib 2a of the other deck plate 70b of each pair is in surface contact with the first protruding streak portion 4a. The first protruding streak portion 4a is provided on the contact part 3b of the one deck plate 70a of each pair, and the recessed part 13c provided on the bottom surface part 13b of the rib 1a of the other deck plate 70b of each pair is in surface contact with the first protruding streak portion 4a.

The first protruding streak portion 4a is provided on the contact part 3a of the other deck plate 70b of each pair, and the recessed part 23c provided on the bottom surface part 23b of the rib 2a of the one deck plate 70a of each pair is in surface contact with the first protruding streak portion 4a. The first protruding streak portion 4a is provided on the contact part 3b of the other deck plate 70b of each pair, and the recessed part 13c provided on the bottom surface part 13b of the rib 1a of the one deck plate 70a of each pair is in surface contact with the first protruding streak portion 4a.

Further, in a state where the plurality of pairs of deck plates 70a and 70b stacked while being turned upside down relative to each other are stacked (two pairs in FIG. 7), the second protruding streak portions 4b of the deck plate 70b out of the deck plates 70a and 70b in a pair positioned on an upper side are in surface contact with the first protruding streak portions 4a of the deck plate 70a out of the deck plates 70a and 70b in a pair positioned on a lower side. More specifically, the second protruding streak portions 4b are fitted into the respective first protruding streak portions 4a, and protruding surfaces of the second protruding streak portions 4b is in surface contact with bottom surfaces of the first protruding streak portions 4a over substantially the entire regions.

The first protruding streak portions 4a of the deck plate 70b out of the deck plates 70a and 70b in a pair positioned on the upper side are in surface contact with the second protruding streak portions 4b of the deck plate 70a out of the deck plates 70a and 70b in a pair positioned on the lower side. More specifically, the second protruding streak portions 4b are fitted into the respective first protruding streak portions 4a, and the protruding surfaces of the second protruding streak portions 4b are in surface contact with the bottom surfaces of the first protruding streak portions 4a over substantially the entire regions.

In the state illustrated in FIG. 7, the contact areas of the protruding streak portions 4a and 4b and the ribs 1a and 2a of the deck plates 70a and 70b in each pair are large, and the heights of the deck plates 70a and 70b in each pair are equal to each other. Thus, a stable state is established.

Note that, in the second embodiment, the recessed parts 13c and 23c provided on the bottom surface parts 13b and 23b of the ribs 1a and 2a and the second protruding streak portions 4b protruding in a direction opposite to the protruding direction of the first protruding streak portions 4a so as to be fitted into the first protruding streak portions 4a are provided; however, the deck plate may include any ones of these components.

According to the above-described deck plate 70, when the deck plates 70a and 70b in a pair are stacked while being turned upside down relative to each other, the contact areas of the bottom surfaces of the ribs 1a and 2a and the first protruding streak portions 4a can be maximally secured because the bottom surfaces of the ribs 1a and 2a and the first protruding streak portions 4a contacting the bottom surfaces of the ribs 1a and 2a are formed in complementary shapes. Further, the heights at respective positions when the deck plates 70a and 70b in a pair are stacked are equal to one another, and the deck plates 70 can be stacked in the stable state. Therefore, when the plurality of pairs of stacked deck plates 70a and 70b are stacked and tied with the band to form the package, a fulcrum at which the ends of the deck plates 70a and 70b in the transverse direction are bent by the band does not occur. Thus, the deck plates 70a and 70b are not floated, and are prevented from being bent. This makes it possible to ship the deck plates 70a and 70b in a state where quality of products is maintained.

Further, the recessed parts 13c and 23c formed in the shapes complementary to the first protruding streak portions 4a provided on the contact parts 3a and 3b with which the ribs 1a and 2a contact are provided on the bottom surface parts 13b and 23b of the ribs 1a and 2a. Thus, the first protruding streak portions 4a are fitted into the recessed parts 13c and 23c to function as stoppers regulating movement of the both deck plates 70a and 70b in the transverse direction.

Further, when the recessed parts 13c and 23c are formed on the bottom surface parts 13b and 23b of the ribs 1a and 2a, the ribs 1a and 2a and the plane portions 3 can be brought into surface contact with each other to enable stable stacking irrespective of presence/absence of the first protruding streak portions 4 on the contact parts.

The second protruding streak portions 4b of the deck plate 70b out of the deck plates 70a and 70b in a pair positioned on the upper side come into surface contact with the first protruding streak portions 4a of the deck plate 70a out of the deck plates 70a and 70b in a pair positioned on the lower side. The first protruding streak portions 4a of the deck plate 70b out of the deck plates 70a and 70b in a pair positioned on the upper side come into surface contact with the second protruding streak portions 4b of the deck plate 70a out of the deck plates 70a and 70b in a pair positioned on the lower side. Thus, the first protruding streak portions 4a and the second protruding streak portions 4b are fitted into each other to function as stoppers regulating movement of the adjacent deck plates 70a and 70b in a pair in the transverse direction. Further, when the plurality of pairs of deck plates 70a and 70b are stacked, the positioning can be performed by fitting the first protruding streak portions 4a and the second protruding streak portions 4b facing each other. This facilitates the stacking work.

<Others>

Although the preferred embodiments of the present invention are described above, the present invention is not limited to the above-described embodiments, and includes any aspect included in the concept and the claims of the present invention. Further, the components may be appropriately selectively combined so as to achieve at least a part of the above-described objects and effects. For example, the shape, the material, the arrangement, the size, and the like of each component in the above-described embodiments may be appropriately changed depending on a specific usage of the present invention.

For example, the number, the interval, the shapes, and the like of the ribs and the protruding streak portions in the deck plate are freely changeable within the scope realizing the present invention.

Further, among the plurality of combinations of the bottom surfaces of the ribs and the contact parts of the plane portions when the deck plates in a pair are stacked while being turned upside down relative to each other, some of the combinations may be formed in the complementary shapes.

LIST OF REFERENCE SIGNS

• • 10, 10a, 10b, 70, 70a, 70b deck plate
  • 1, 2, 1a, 2a rib
  • 3 plane portion
  • 3a, 3b contact part
  • 4 protruding streak portion
  • 4a first protruding streak portion
  • 4b second protruding streak portion
  • 13b, 23b bottom surface part
  • 13c, 23c recessed part