FLOOR PANEL

Abstract

The invention provides a floor panel which can prevent the cable such as the wiring arranged in the space between the floor panel and the floor surface from being damaged due to the contact with the leading end angled portion of the floor panel, and can prevent a manufacturing cost from being increased on the basis of its simple structure. In a floor panel (40) provided with a plate-like top plate portion (44) which has a plane portion and four edges in a peripheral portion thereof, and a plurality of side plate portions (46) which are formed by being folded from the four edges, and supported to a support table (6) so as to construct a free access floor (42), the side plate portions (46) are folded and folded portions (46c) are formed in lower end portions of the side plate portions (46).

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a floor panel which is used in a free access floor.

2. Description of the Conventional Art

The floor panel according to the present invention is used in the free access floor. The floor panel of the free access floor is provided above a concrete floor surface which constructs a part of a building construction, for forming a second floor surface so as to be spaced from the floor surface via a support table (refer, for example, to patent document 1).

FIGS. 12 to 18 are views which are referred for describing a conventional floor panel 2. Here, FIG. 12 is a top elevational view in a midstream stage of an installing work of a free access floor 4 using the conventional floor panel 2, and FIG. 13 is a partly enlarged side elevational view in which a part of a side surface of the free access floor 4 in FIG. 12 is enlarged.

The conventional floor panel 2 is structured, as shown in FIG. 13, such as to construct the free access floor 4 together with a support table 6 which is provided in a rising manner via a connection member 8, on a floor surface 3 which is formed by a concrete material constructing a part of the building construction.

In other words, the connection member 8 is constructed by being provided with nine support portions 12 which support nine support tables 6 arranged three lines by three lines in an up and down direction and a right and left direction of the drawing, and connection portions 10 which connect nine support portions 12 in the up and down direction or the right and left direction of the drawing, as shown in FIG. 12.

Further, each of the connection members 8 is arranged so as to be away from each other on the floor surface 3, in such a manner that a distance between center portions of the support table 6 supported to the support portion 12 arranged in an outer peripheral portion, and the support table 6 supported by the support portion 12 of the other adjacent connection member 8 opposing to the above-mentioned support table 6 is approximately the same length as a length of one edge of the floor panel 2.

The support table 6 is arranged on the floor surface 3 via the connection member 8 and is arranged in a rising manner by filling its lower end portion to a concave portion formed in the support portion 12 of the connection member 8 from the above, as shown in FIG. 13.

Each of the support tables 6 is arranged so as to be away from each other in such a manner that the distance between the centers of the support table 6 and the other support table 6 which is adjacent in the up and down direction or the right and left direction in FIG. 12 is approximately the same length as the length of one edge of the floor panel 2.

In the support table 6, as shown its top elevational view in FIG. 14, four groove portions 6b are formed so as to be open to have a depth in a far side of the paper surface of the drawing from an upper end surface 6a, the groove portion 6b being capable of engaging with a side plate portion 16 of the floor panel 2 mentioned later.

Two groove portions 6b among four groove portions 6b formed in the support table 6 are arranged so as to extend in a vertical direction in FIG. 14 approximately in parallel to each other, and the other two groove portions 6b are arranged so as to extend in a lateral direction in the drawing approximately in parallel to each other, and are orthogonal to two groove portions 6b extending in the vertical direction, in a center portion of the upper end surface 6a of the support table 6.

Further, a rib 6c protruding to an inner side of the groove portion 6b from a side surface portion in one side of the groove portion 6b is formed in a length midstream portion of each of four groove portions 6b of the support table 6. The rib 6c has an elasticity and a flexibility and is structured such as to generate a repulsive force (pressing force) intending to return to the original shape by pressing and deflecting the rib 6c.

The conventional floor panel 2 is formed its shape by press molding one metal plate-like member, and is structured, as shown in FIG. 15, such as to be provided with a top plate portion 14 which has an approximately square shaped upper surface 14a and formed as a plate shape, and four side plate portions 16 (refer to FIG. 18) which are formed by being folded approximately vertically downward from four edges of the top plate portion 14.

Further, in the conventional floor panel 2, two long groove portions 14b are formed so as to extend so as to be along one edge of the top plate portion 14, and be depressed to a back side in a thickness direction in relation to the upper surface 14a. These two long groove portions 14b are arranged approximately in parallel so as to be spaced from each other in a vertical direction in FIG. 15.

Further, in the conventional floor panel 2, an opening portion 14c is formed in each of four edges of the top plate portion 14, the opening portion 14c having an opening shape which is notched approximately as a rectangular shape to an inner side in a horizontal direction together with the side plate portion 16 below the top plate portion 14, and passing through in a thickness direction of the top plate portion 14.

As shown in FIG. 16, in the conventional floor panel 2, a protruding portion 16b is formed in a center portion in a length direction of the side plate portion 16 (a vertical direction of the drawing), the protruding portion 16b protruding so that a dimension difference in a height direction (a lateral direction of the drawing) is larger than that of step surfaces 16a in both end portions.

In the conventional floor panel 2 mentioned above, as shown in FIG. 17, an end portion in a length direction in which the step surface 16a of the side plate portion 16 is formed fits into the grove portion 6b of the support table 6 from an upper side of the drawing, and a back surface of the upper surface 14a of the top plate portion 14 comes into contact with the upper end surface 6a of the support table 6, whereby the floor panel 2 is detachably supported to a predetermined height position on the floor surface 3.

In this case, the end portions of a pair of side plate portions 16 which are adjacent so as to be orthogonal to each other in their lengths fit into the groove portions 6b which are provided in the adjacent area side portions of a quarter area obtained by dividing the upper end surface 6a in FIG. 14 of the support table 6 every 90 degrees and are formed as an L-shaped form so as to be orthogonal to each other, and a pair of side plate portions 16 are pressed by a rib 6c formed in an inner side of the groove portion 6b of the support table 6 from its side direction, so as to prevent the floor panel 2 from easily getting away upward from the support table 6.

As shown in FIG. 12, in the conventional floor panel 2, four floor panels are arranged and mounted two by two in each of a vertical direction and a lateral direction of the drawing, in such a manner that corner portions of the top plate portions 14 confront each other, on nine support tables 6 which are supported by one connection member 8.

Further, the other floor panel 2 is mounted on the upper end surfaces 6a of the support tables 6 protruding to an outer side in a horizontal direction from a plurality of floor panels 2 arranged so as to be spaced from each other, in such a manner as to bridge between a plurality of floor panels 2 arranged so as to be space from each other in FIG. 12, although an illustration is omitted.

As a result, the conventional floor panel 2 is structured such as to be arranged with no gap vertically and laterally in FIG. 12 and form a second floor surface while being spaced above the floor surface 3, in the case that an installing work of the free access floor 4 using the same is finished.

Since the shape of the conventional floor panel 2 is formed by press molding one metal plate-like member, a construction thereof is simple and it is possible to prevent a manufacturing cost from being increased.

Further, the conventional floor panel 2 is structured such that a cable such as a wiring can be arranged in a space between the top plate portion 14 of the floor panel 2 and the floor surface 3, in the case of being used in the free access floor 4.

PRIOR ART DOCUMENT

Patent Document

• Patent Document 1: Japanese Patent No. 2778538

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

However, since the shape of the conventional floor panel 2 is formed by press molding the plate-like member cut into a predetermines shape as it is, a sharp leading end angled portion 16c is formed in a leftward lower end in the drawing of the side plate portion 16, as shown in FIG. 18. Therefore, there is a problem that a length midstream portion of the cable such as the wiring arranged in the space between the floor panel 2 and the floor surface 3 comes into contact with the leading end angled portion 16c of the side plate portion 16 in the floor panel 2, and the contact portion of the cable with the leading end angled portion 16c is damaged so as to cause an accident.

Accordingly, the present invention is made by taking the problem mentioned above into consideration, and an object of the present invention is to provide a floor panel which can prevent the cable such as the wiring arranged in the space between the floor panel and the floor surface from being damaged due to the contact with the leading end angled portion of the floor panel, and can prevent a manufacturing cost from being increased on the basis of its simple structure.

Means for Solving the Problem

In order to achieve the object mentioned above, according to the present invention, there is provided a floor panel comprising:

a plate-like top plate portion which has a plane portion and four edges in a peripheral portion thereof;

a plurality of side plate portions which are formed by being folded from the four edges; and

the floor panel being supported to a support table so as to construct a free access floor,

wherein the side plate portions are folded and folded portions are formed in lower end portions of the side plate portions.

Further, according to the present invention, there is provided the floor panel, wherein leading end plate portions are formed in the side plate portions so as to be connected via the folded portions, and

wherein leading end portions in an opposite side to end portions connected to the folded portions of the leading end plate portions are arranged at positions closer to a center portion of the plane portion in relation to the folded portions.

Further, in order to achieve the object mentioned above, according to the present invention, there is provided a floor panel comprising:

a plate-like top plate portion which has a plane portion and four edges in a peripheral portion thereof;

a plurality of side plate portions which are formed by being folded from the four edges; and

the floor panel being supported to a support table so as to construct a free access floor,

wherein a round process is applied to lower end portions of the side plate portions and curved surface portions are formed.

Further, in order to achieve the object mentioned above, according to the present invention, there is provided a floor panel comprising:

a plate-like top plate portion which has a plane portion and four edges in a peripheral portion thereof;

a plurality of side plate portions which are formed by being folded from the four edges; and

the floor panel being supported to a support table so as to construct a free access floor,

wherein a chamfer process is applied to lower end portions of the side plate portions and inclined surface portions which are inclined to side surfaces and/or lower end surfaces of the side plate portions are formed.

Effect of the Invention

According to the floor panel of the present invention mentioned above, in the floor panel provided with the plate-like top plate portion which has the plane portion and four edges in the peripheral portion thereof, and a plurality of side plate portions which are formed by being folded from the four edges, and supported to the support table so as to construct the free access floor, the side plate portions are folded and the folded portions are formed in the lower end portions of the side plate portions. Accordingly, it is possible to prevent the cable such as the wiring arranged in the space between the floor panel and the floor surface from being damaged by the contact with the leading end angled portion of the floor panel, and it is possible to prevent the manufacturing cost from being increased on the basis of its simple structure of the floor panel.

Further, according to the floor panel of the present invention, in the floor panel provided with the plate-like top plate portion which has the plane portion and four edges in the peripheral portion thereof, and a plurality of side plate portions which are formed by being folded from the four edges, and supported to the support table so as to construct the free access floor, the round process is applied to the lower end portions of the side plate portions and the curved surface portions are formed. Accordingly, it is possible to prevent the cable such as the wiring arranged in the space between the floor panel and the floor surface from being damaged by the contact with the leading end angled portion of the floor panel, and it is possible to prevent the manufacturing cost from being increased on the basis of its simple structure of the floor panel.

Further, according to the floor panel of the present invention, in the floor panel provided with the plate-like top plate portion which has the plane portion and four edges in the peripheral portion thereof, and a plurality of side plate portions which are formed by being folded from the four edges, and supported to the support table so as to construct the free access floor, the chamfer process is applied to the lower end portions of the side plate portions and the inclined surface portions which are inclined to the side surfaces and/or the lower end surfaces of the side plate portions are formed. Accordingly, it is possible to prevent the cable such as the wiring arranged in the space between the floor panel and the floor surface from being damaged by the contact with the leading end angled portion of the floor panel, and it is possible to prevent the manufacturing cost from being increased on the basis of its simple structure of the floor panel.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 is a top elevational view of a floor panel 40 according to a first embodiment of the present invention;

FIG. 2 is a side elevational view of the floor panel 40 in FIG. 1;

FIG. 3 is a cross sectional view of the floor panel 40 in FIG. 1 as seen from an arrow B-B;

FIG. 4 is a view showing a floor panel 50 according to a second embodiment of the present invention, and is a cross sectional view corresponding to a cross sectional view of the floor panel 40 in FIG. 1 as seen from the arrow B-B;

FIG. 5 is a view showing a floor panel 60 according to a third embodiment of the present invention, and is a cross sectional view corresponding to a cross sectional view of the floor panel 40 in FIG. 1 as seen from the arrow B-B;

FIG. 6 is a view showing a floor panel 70 according to a fourth embodiment of the present invention, and is a cross sectional view corresponding to a cross sectional view of the floor panel 40 in FIG. 1 as seen from the arrow B-B;

FIG. 7 is a view showing a floor panel 80 according to a fifth embodiment of the present invention, and is a cross sectional view corresponding to a cross sectional view of the floor panel 40 in FIG. 1 as seen from the arrow B-B;

FIG. 8 is a top elevational view of a floor panel 90 according to a sixth embodiment of the present invention;

FIG. 9 is a side elevational view of the floor panel 90 in FIG. 8;

FIG. 10 is a view showing a floor panel 100 according to a seventh embodiment of the present invention, and is a cross sectional view corresponding to a cross sectional view of the floor panel 40 in FIG. 1 as seen from the arrow B-B;

FIG. 11 is a view showing a floor panel 110 according to an eighth embodiment of the present invention, and is a cross sectional view corresponding to a cross sectional view of the floor panel 40 in FIG. 1 as seen from the arrow B-B;

FIG. 12 is a top elevational view showing a midstream stage of an installing work of a free access floor 4 or 42 which is constructed by using the floor panel 2 or 40;

FIG. 13 is a partly enlarged side elevational view showing a part of a side surface of the free access floor 4 or 42 in FIG. 12 in an enlarged manner;

FIG. 14 is an enlarged top elevational view of a support table 6 in FIG. 12;

FIG. 15 is a top elevational view of a conventional floor panel 2;

FIG. 16 is a side elevational view of the conventional floor panel 2 in FIG. 15;

FIG. 17 is a view for describing a work for attaching the conventional floor panel 2 in FIG. 12 to the support table 6, and an assembled side elevational view of the conventional free access floor 4; and

FIG. 18 is a cross sectional view of the conventional floor panel 2 in FIG. 15 as seen from an arrow A-A.

DESCRIPTION OF REFERENCE NUMERALS

• 2 floor panel
• 3 floor surface
• 4 free access floor
• 6 support table
• 6 a upper end surface
• 6 b groove portion
• 6 c rib
• 8 connection member
• 10 connection portion
• 12 support portion
• 14 top plate portion
• 14 a upper surface
• 14 b long groove portion
• 14 c opening portion
• 16 side plate portion
• 16 a step surface
• 16 b protruding portion
• 16 c leading end angled portion
• 40 floor panel
• 42 free access floor
• 44 top plate portion
• 44 a upper surface
• 44 b long groove portion
• 44 c opening portion
• 46 side plate portion
• 46 a step surface
• 46 b protruding portion
• 46 c folded portion
• 48 leading end plate portion
• 48 a leading end angled portion
• 50 floor panel
• 52 side plate portion
• 52 a step surface
• 52 b protruding portion
• 52 c folded portion
• 54 leading end plate portion
• 54 a leading end angled portion
• 60 floor panel
• 62 side plate portion
• 62 a step surface
• 62 b protruding portion
• 62 c folded portion
• 64 leading end plate portion
• 64 a leading end angled portion
• 70 floor panel
• 72 side plate portion
• 72 a step surface
• 72 b protruding portion
• 72 c curved surface portion
• 80 floor panel
• 82 side plate portion
• 82 a step surface
• 82 b protruding portion
• 82 c taper surface portion
• 90 floor panel
• 92 top plate portion
• 92 a upper surface
• 92 b long groove portion
• 92 c opening portion
• 94 side plate portion
• 94 a step surface
• 94 b protruding portion
• 94 c folded portion
• 96 leading end plate portion
• 96 a leading end angled portion
• 100 floor panel
• 102 side plate portion
• 102 a step surface
• 102 b protruding portion
• 102 c folded portion
• 104 leading end plate portion
• 104 a leading end angled portion
• 110 floor panel
• 112 side plate portion
• 112 a step surface
• 112 b protruding portion
• 112 c folded portion
• 114 leading end plate portion
• 114 a leading end angled portion

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A description will be specifically given below of modes for carrying out a floor panel according to the present invention with reference to the accompanying drawings.

FIGS. 1 to 3 and FIGS. 12 to 14 are views which are referred for describing a floor panel 40 according to a first embodiment of the present invention. A description will be given below of the same portions as those of the conventional floor panel 2 by attaching the same reference numerals, and an overlapping description of the same structures as the conventional ones will be omitted except a part thereof.

The floor panel 40 according to the present embodiment is significantly different from the conventional floor panel 2 in a point that side plate portions 46 and leading end plate portions 48 are provided as shown in FIG. 3 are provided in place of the side plate portions 16 of the conventional floor panel 2 shown in FIG. 18.

In other words, the floor panel 40 according to the present embodiment is structured, as shown in FIGS. 12 and 13, such that a free access floor 42 is constructed together with support tables 6 which are provided in a rising manner via connection members 8, on a floor surface 3 which constructs a part of a building construction and is formed by a concrete material.

The floor panel 40 according to the present embodiment is formed its shape by press molding one metal plate-like member, and is structured, as shown in FIG. 1, such as to be provided with a top plate portion 44 (a plane portion) which is formed as a plate shape having an approximately square upper surface 44a, four side plate portions 46 (refer to FIG. 3) which are formed by being folded approximately vertically downward from four edges of the top plate portion 44, and four leading end plate portions 48 which are respectively connected to four side plate portions 46 via folded portions 46c (refer to FIG. 3).

Further, two long groove portions 44b are formed in the floor panel 40, the long groove portion 44b extending so as to be along one edge of the top plate portion 44 and being concaved to a back side in a thickness direction from an upper surface 44a. These two long groove portions 44b are arranged approximately in parallel so as to be spaced from each other in a vertical direction in FIG. 1.

Further, in the floor panel 40, an opening portion 44c is formed in each of four edges of the top plate portion 44, the opening portion 44c having such an opening shape as to be notched approximately as a rectangular shape to an inner side in a horizontal direction together with the side plate portion 46 below the top plate portion 44, and passing through in a thickness direction of the top plate portion 44, in the same manner as the opening portion 14c of the conventional floor panel 2 shown in FIG. 15.

As shown in FIG. 2, in the floor panel 40, a protruding portion 46b is formed in a center portion in a length direction (a vertical direction of the drawing) of the side plate portion 46 which is folded perpendicularly from the top plate portion 44 so as to be connected, the protruding portion 46b protruding so that a dimension difference in its height direction (a lateral direction in the drawing) is larger than step surfaces 46a in both end portions thereof.

In FIG. 3, as a matter of convenience for describing, the protruding portion 46b of the side plate portion 46 in the floor panel 40 and a plate portion positioned in an upper side in the drawing than the step surface 46a of the side plate portion 46 are drawn so as to be sectioned part by part by a broken line, however, there is not actually any boundary sectioning them as shown in FIG. 2, and they are continuously formed as a whole.

The protruding portion 46b of the side plate portion 46 is folded in the folded portion 46c of the lower end portion as shown in FIG. 3, and is connected to a leading end plate portion 48 formed closer to a leading end portion than the folded portion 46c via the folded portion 46c. The folded portion 46c of the side plate portion 46 is formed approximately as a U-shaped form in its cross sectional shape.

In the leading end plate portion 48 of the floor panel 40, since the protruding portion 46b of the side plate portion 46 is folded in the folded portion 46c, a leading end portion having a leading end angled portion 48a in an opposite side to the end portion connected to the folded portion 46c is arranged away from the upper surface 44a of the top plate portion 44 at a distance which is shorter than a distance from the upper surface 44a of the top plate portion 44 to the lowest end of the folded portion 46c (the shortest distance).

Further, the leading end portion 48 of the floor panel 40 is arranged in a right side in FIG. 3 in relation to the side plate portion 46. In other words, the leading end plate portion 48 is arranged in an inner side of the side plate portion 46 (closer to the center portion of the top plate portion 44).

As a result, in the floor panel 40, the leading end angled portion 48a of the leading end plate portion 48 corresponding to the leading end angled portion 16c of the side plate portion 16 in the conventional floor panel 2 is arranged closer to the upper surface 44a of the top plate portion 44 than the lowest end of the folded portion 46c and is arranged in the inner side of the side plate portion 46 which is folded perpendicularly from the top plate portion 44 so as to be connected.

Further, in the floor panel 40, the folded portion 46c is formed in a portion corresponding to the lower end portion of the side plate portion 16 in which the leading end angled portion 16c of the conventional floor panel 2 in FIG. 18 is formed, the folded portion 46c being formed approximately as a U-shaped form in its cross sectional shape and being formed as a circular arc curved shape in its outer profile, as shown in FIG. 3.

Further, in the floor panel 40, an end portion in a length direction of the side plate portion 46 in which the step surface 46a is formed fits into the groove portion 6b of the support table 6 from the above, and a back surface of the top plate portion 44 comes into contact with the upper end surface 6a of the support table 6, in the same manner as the conventional floor panel 2 shown in FIG. 17, whereby the floor panel 40 is detachably supported to a predetermined height position on the floor surface 3.

In this case, the end portions of a pair of side plate portions 46 which are adjacent so as to be orthogonal to each other in their lengths fit into the groove portions 6b which are provided in the adjacent area side portions of a quarter area obtained by dividing the upper end surface 6a in FIG. 14 of the support table 6 every 90 degrees and are formed as an L-shaped form so as to be orthogonal to each other, and a pair of side plate portions 46 are pressed by a rib 6c formed in an inner side of the groove portion 6b of the support table 6 from its side direction, so as to prevent the floor panel 40 from easily getting away upward from the support table 6.

As shown in FIG. 12, in the floor panel 40, four floor panels are arranged and mounted two by two in each of a vertical direction and a lateral direction of the drawing, in such a manner that corner portions of the top plate portions 44 confront each other, on nine support tables 6 which are supported by one connection member 8, in the same manner as the conventional floor panel 2.

Further, the other floor panel 40 is mounted on the upper end surfaces 6a of the support tables 6 protruding to an outer side in a horizontal direction from a plurality of floor panels 40 arranged so as to be spaced from each other, in such a manner as to bridge between a plurality of floor panels 40 arranged so as to be space from each other in FIG. 12, although an illustration is omitted.

As a result, the floor panel 40 is structured such as to be arranged with no gap vertically and laterally in FIG. 12 and form a second floor surface while being spaced above the floor surface 3, in the case that an installing work of the free access floor 42 using the same is finished.

In the floor panel 40 according to the present embodiment, since the folded portion 46c is formed in the portion corresponding to the lower end portion of the side plate portion 16 in which the leading end angled portion 16c is formed in the conventional floor panel 2 in FIG. 18, the leading end angled portion 48a of the leading end plate portion 48 is arranged closer to the upper surface 44a of the top plate portion 44 than the lowest end of the folded portion 46c, and is arranged in the inner side than the side plate portion 46, it is possible to prevent the length midstream portion of the cable such as the wiring arranged in the space between the floor panel 40 and the floor surface 3 from coming into contact with the leading end angled portion 48a of the leading end plate portion 48.

As a result, in the floor panel 40 according to the present embodiment, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged by the contact with the leading end angled portion 48a of the leading end plate portion 48 so as to cause an accident.

Further, in the floor panel 40 according to the present embodiment, since the folded portion 46c of the side plate portion 46 is formed, and a section modulus and a geometrical moment of inertia become higher, it is possible to suppress deflection of the floor panel 40.

Further, in the floor panel 40 according to the present embodiment, since the shape including the folded portion 46c of the side plate portion 46 is formed by press molding the plate-like member cut into the predetermined shape as it is, the structure is simple and it is possible to prevent the manufacturing cost from being increased.

As mentioned above, on the basis of the floor panel 40 according to the present embodiment, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged by the contact with the leading end angled portion 48a, and it is possible to prevent the manufacturing cost from being increased on the basis of the simple structure.

Further, on the basis of the floor panel 40 according to the present embodiment, it is possible to suppress the deflection of the floor panel 40.

FIG. 4 is a view which is referred for describing a floor panel 50 according to a second embodiment of the present invention.

The floor panel 50 according to the present embodiment is different from the floor panel 40 according to the first embodiment mentioned above in a point that a folded portion 52c of a side plate portion 52 and a leading end plate portion 54 as shown in FIG. 4 are provided in place of the folded portion 46c of the side plate portion 46 and the leading end plate portion 48 in the first embodiment mentioned above.

In other words, the side plate portion 52 of the floor panel 50 is different from the side plate portion 46 according to the first embodiment mentioned above in a point that the leading end plate portion 54 is folded so as to form an inner side of the side plate portion 52 in the folded portion 52c in a lower end portion of a protruding portion 52b, and a cross sectional shape of the side plate portion 52 is formed approximately as a V-shaped form, as shown in FIG. 4.

Further, a step surface 52a and a protruding portion 52b of the side plate portion 52 and a leading end angled portion 54a of the leading end plate portion 54 in the floor panel 50 are the same as the step surface 46a and the protruding portion 46b of the side plate portion 46 and the leading end angled portion 48a of the leading end plate portion 48 according to the first embodiment mentioned above, except a point that respective positional relationships are somewhat different according to the folded portion 52c.

In FIG. 4, as a matter of convenience for describing, the protruding portion 52b of the side plate portion 52 in the floor panel 50 and a plate portion positioned in an upper side in the drawing than the step surface 52a of the side plate portion 52 are drawn so as to be sectioned part by part by a broken line, however, there is not actually any boundary sectioning them in the same manner as the side plate portion 46 in the first embodiment mentioned above, and they are continuously formed as a whole. This point is applied in the same manner to side plate portions 62, 102 and 112 in FIGS. 5, 10 and 11 mentioned later.

As shown in FIG. 4, in the side plate portion 52 of the floor panel 50, since the folded portion 52c is formed in a lower end portion of the protruding portion 52b, an angle between the side plate portion 52 and the leading end plate portion 54 is an acute angle.

As a result, in the leading end plate portion 54 of the floor panel 50, a leading end portion having a leading end angled portion 54a in an opposite side to the end portion connected to the folded portion 52c is arranged away from the upper surface 44a of the top plate portion 44 at a distance which is shorter than a distance from the upper surface 44a of the top plate portion 44 to the lowest end of the folded portion 52c.

Further, in the floor panel 50, the leading end angled portion 54a of the leading end plate portion 54 corresponding to the leading end angled portion 16c of the side plate portion 16 in the conventional floor panel 2 is arranged closer to the upper surface 44a of the top plate portion 44 than the lowest end of the folded portion 52c and is arranged in the inner side of the side plate portion 52.

Further, in the floor panel 50, the folded portion 52c is formed in a portion corresponding to the lower end portion of the side plate portion 16 in which the leading end angled portion 16c of the conventional floor panel 2 in FIG. 18 is formed, the folded portion 52c being formed approximately as a V-shaped form in its cross sectional shape and being formed as a circular arc curved shape in its outer profile.

As a result, in the floor panel 50 according to the present embodiment, since the cable such as the wiring arranged in the space in relation to the floor surface 3 does not come into contact with the leading end angled portion 54a of the leading end plate portion 54, it is possible to prevent the cable from being damaged so as to cause an accident.

Further, in the floor panel 50 according to the present embodiment, since the shape thereof including the folded portion 52c of the side plate portion 52 is formed by press molding the plate-like member cut into a predetermined shape as it is, the structure thereof is simple and it is possible to prevent a manufacturing cost from being increased.

Accordingly, on the basis of the floor panel 50 according to the present embodiment, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged by the contact with the leading end angled portion 54a of the leading end plate portion 54, and it is possible to prevent the manufacturing cost from being increased on the basis of the simple structure, in the same manner as the floor panel 40 according to the first embodiment mentioned above.

Further, on the basis of the floor panel 50 according to the present embodiment, since the folded portion 52c of the side plate portion 52 is formed, and a section modulus and a geometrical moment of inertia become higher, it is possible to suppress deflection of the floor panel 50.

FIG. 5 is a view which is referred for describing a floor panel 60 according to a third embodiment of the present invention.

The floor panel 60 according to the present embodiment is different from the floor panel 50 according to the second embodiment mentioned above in a point that a folded portion 62c of a side plate portion 62 and a leading end plate portion 64 as shown in FIG. 5 are provided in place of the folded portion 52c and the leading end plate portion 54 of the side plate portion 52 in the second embodiment mentioned above.

In other words, the side plate portion 62 of the floor panel 60 is different from the side plate portion 52 according to the second embodiment mentioned above in a point that the leading end plate portion 64 is folded so as to form an inner side of the side plate portion 62 in the folded portion 62c in a lower end portion of a protruding portion 62b, and a cross sectional shape of the side plate portion 62 is formed approximately as an L-shaped form, as shown in FIG. 5.

Further, a step surface 62a and a protruding portion 62b of the side plate portion 62 and a leading end angled portion 64a of the leading end plate portion 64 in the floor panel 60 are the same as the step surface 52a and the protruding portion 52b of the side plate portion 52 and the leading end angled portion 54a of the leading end plate portion 54 according to the second embodiment mentioned above, except a point that respective positional relationships are somewhat different according to the folded portion 62c.

As shown in FIG. 5, in the side plate portion 62 of the floor panel 60, since the folded portion 62c is formed in a lower end portion of the protruding portion 62b, an angle between the side plate portion 62 and the leading end plate portion 64 is approximately perpendicular.

As a result, in the leading end plate portion 64 of the floor panel 60, a leading end portion having a leading end angled portion 64a in an opposite side to the end portion connected to the folded portion 62c is arranged away from the upper surface 44a of the top plate portion 44 at a distance which is approximately equal to or shorter than a distance from the upper surface 44a of the top plate portion 44 to the lowest end of the folded portion 62c.

Further, in the floor panel 60, the leading end angled portion 64a of the leading end plate portion 64 corresponding to the leading end angled portion 16c of the side plate portion 16 in the conventional floor panel 2 is arranged away from the upper surface 44a of the top plate portion 44 approximately at the same distance as the distance from the upper surface 44a of the top plate portion 44 to the lowest end of the folded portion 62c and is arranged in the inner side of the side plate portion 62.

Further, in the floor panel 60, the folded portion 62c is formed in a portion corresponding to the lower end portion of the side plate portion 16 in which the leading end angled portion 16c of the conventional floor panel 2 in FIG. 18 is formed, the folded portion 62c being formed approximately as an L-shaped form in its cross sectional shape and being formed as a 90-degrees circular arc curved shape in its outer profile.

As a result, in the floor panel 60 according to the present embodiment, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged so as to cause an accident due to the contact with the leading end angled portion 64a of the leading end plate portion 64.

Further, in the floor panel 60 according to the present embodiment, since the shape thereof including the folded portion 62c of the side plate portion 62 is formed by press molding the plate-like member cut into a predetermined shape as it is, the structure thereof is simple and it is possible to prevent a manufacturing cost from being increased.

Accordingly, on the basis of the floor panel 60 according to the present embodiment, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged by the contact with the leading end angled portion 64a of the leading end plate portion 64, and it is possible to prevent the manufacturing cost from being increased on the basis of the simple structure, in the same manner as the floor panel 50 according to the second embodiment mentioned above.

Further, on the basis of the floor panel 60 according to the present embodiment, since the folded portion 62c of the side plate portion 62 is formed, and a section modulus and a geometrical moment of inertia become higher, it is possible to suppress deflection of the floor panel 60.

FIG. 6 is a view which is referred for describing a floor panel 70 according to a fourth embodiment of the present invention.

The floor panel 70 according to the present embodiment is different from the floor panel 60 according to the third embodiment mentioned above in a point that a curved surface portion 72c is provided in a leading end portion of a side plate portion 72 as shown in FIG. 6, in place of the folded portion 62c of the side plate portion 62 and the leading end angled portion 64a of the leading end plate portion 64 in the third embodiment mentioned above.

In other words, the side plate portion 72 of the floor panel 70 is different from the side plate portion 62 according to the third embodiment mentioned above in a point that a protruding portion 72b is formed so as to extend straightly to a lower side in the drawing in relation to a step surface 72a without being folded in a lower end portion thereof, and a round process is applied to a leading end portion according to a cutting, whereby the curved surface portion 72c is formed so that an outer profile is formed as a circular arc curved surface shape, as shown in FIG. 6.

In the floor panel 70 according to the present embodiment, since the outer profile of the curved surface portion 72c in the leading end portion of the side plate portion 72 is formed as the circular arc curved surface shape, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged due to the contact.

In the floor panel 70 according to the present embodiment mentioned above, since the shape thereof is formed by press molding the plate-like member cut into a predetermined shape as it is, and forming the curved surface portion 72c of the side plate portion 72 by the cutting process, the structure thereof is simple and it is possible to prevent a manufacturing cost from being increased.

Accordingly, on the basis of the floor panel 70 according to the present embodiment, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged by the contact with the curved surface portion 72c of the side plate portion 72, and it is possible to prevent the manufacturing cost from being increased on the basis of the simple structure, in the same manner as the floor panel 60 according to the third embodiment mentioned above.

FIG. 7 is a view which is referred for describing a floor panel 80 according to a fifth embodiment of the present invention.

The floor panel 80 according to the present embodiment is different from the floor panel 70 according to the fourth embodiment mentioned above in a point that an inclined surface portion 82c is provided in a leading end portion of a side plate portion 82 as shown in FIG. 7, in place of the curved surface portion 72c in the leading end portion of the side plate portion 72 in the fourth embodiment mentioned above.

In other words, the side plate portion 82 of the floor panel 80 is different from the side plate portion 72 according to the fourth embodiment mentioned above in a point that a protruding portion 82b extends straightly to a lower side in the drawing in relation to a step surface 82a without being folded in a height midstream portion, a chamfer process is applied to a leading end portion thereof according to a cutting process, and the inclined surface portion 82c is formed so as to be inclined in relation of a plane of a plate portion of a base end which is folded perpendicularly from the top plate portion 44 so as to be connected in the side plate portion 82, as shown in FIG. 7.

In the floor panel 80 according to the present embodiment, since an outer profile of the inclined surface portion 82c in the leading end portion of the side plate portion 82 is formed as an inclined surface shape, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged by the contact.

In the floor panel 80 according to the present embodiment mentioned above, since the shape thereof is formed by press molding the plate-like member cut into a predetermined shape as it is, and forming the inclined surface portion 82c of the side plate portion 82 by the cutting process, the structure thereof is simple and it is possible to prevent a manufacturing cost from being increased.

Accordingly, on the basis of the floor panel 80 according to the present embodiment, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged by the contact with the inclined surface portion 82c of the side plate portion 82, and it is possible to prevent the manufacturing cost from being increased on the basis of the simple structure, in the same manner as the floor panel 70 according to the fourth embodiment mentioned above.

FIGS. 8 and 9 are views which are referred for describing a floor panel 90 according to a sixth embodiment of the present invention.

The floor panel 90 according to the present embodiment is formed its shape by press molding one metal plate-like member, and is structured, as shown in FIG. 8, such as to be provided with a top plate portion 92 which has an approximately rectangular upper surface 92a and is formed as a plate shape, six side plate portions 94 (refer to FIG. 9) which are formed by being folded approximately vertical downward from four edges of the top plate portion 92, and six leading end plate portions 96 which are respectively connected to six side plate portions 94 via folded portions 94c (refer to FIG. 9).

The top plate portion 92 of the floor panel 90 according to the present embodiment is provided with two edges which have the same length as one edge of the upper surface 44a of the top plate portion 44 in the floor panel 40 according to the first embodiment, and two edges which have a length being twice the length of one edge of the upper surface 44a of the top plate portion 44.

Further, as shown in FIGS. 8 and 9, a long groove portion 92b and an opening portion 92c of the top plate portion 92, a step surface 94a, a protruding portion 94b and the folded portion 94c of the side plate portion 94, and a leading end angled portion 96a of the leading end plate portion 96 in the floor panel 90 according to the present embodiment are the same as the long groove portion 44b and the opening portion 44c of the top plate portion 44, the step surface 46a, the protruding portion 46b and the folded portion 46c of the side plate portion 46, and the leading end angled portion 48a of the leading end plate portion 48 in the floor panel 40 according to the first embodiment shown in FIGS. 1 and 2.

Further, the floor panel 90 according to the present embodiment is structured such that one floor panel 90 is mounted on six support tables 6, in place of the structure in which two floor panels 40 are arranged in series so as to be mounted on six support tables 6 according to the first embodiment.

As a result, in the floor panel 90 according to the present embodiment, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged by the contact with the leading end angled portion 96a of the leading end plate portion 96 so as to cause an accident.

Further, in the floor panel 90 according to the present embodiment, since the shape thereof including the folded portion 94c of the side plate portion 94 is formed by press molding the plate-like member cut into a predetermined shape as it is, the structure thereof is simple and it is possible to prevent a manufacturing cost from being increased.

Accordingly, on the basis of the floor panel 90 according to the present embodiment, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged by the contact with the leading end angled portion 96a of the leading end plate portion 96, and it is possible to prevent the manufacturing cost from being increased on the basis of the simple structure, in the same manner as the floor panel 40 according to the first embodiment mentioned above.

Further, on the basis of the floor panel 90 according to the present embodiment, since the folded portion 94c of the side plate portion 94 is formed, and a section modulus and a geometrical moment of inertia become higher, it is possible to suppress deflection of the floor panel 90.

FIG. 10 is a view which is referred for describing a floor panel 100 according to a seventh embodiment of the present invention.

The floor panel 100 according to the present embodiment is different from the floor panel 40 according to the first embodiment mentioned above in a point that a folded portion 102c and a leading end plate portion 104 of a side plate portion 102 as shown in FIG. 10 are provided in place of the folded portion 46c and the leading end plate portion 48 of the side plate portion 46 in the first embodiment mentioned above.

Further, a step surface 102a and a protruding portion 102b of the side plate portion 102 and a leading end angled portion 104a of the leading end plate portion 104 in the floor panel 100 are the same as the step surface 46a and the protruding portion 46b of the side plate portion 46 and the leading end angled portion 48a of the leading end plate portion 48 according to the first embodiment mentioned above, except a point that respective positional relationships are somewhat different according to the folded portion 102c.

The side plate portion 102 of the floor panel 100 is different from the side plate portion 46 according to the first embodiment mentioned above, in a point that the leading end plate portion 104 is folded in the protruding portion 102b so as to come to an outer side of the side plate portion 102, and a cross sectional shape of the folded portion 102c is formed approximately as a U-shaped form, as shown in FIG. 10.

In the leading end plate portion 104 of the floor panel 100, since the protruding portion 102b of the side plate portion 102 is folded in the folded portion 102c, a leading end portion having the leading end angled portion 104a in an opposite side to an end portion connected to the folded portion 102c is arranged so as to be away from the upper surface 44a of the top plate portion 44 at a distance which is shorter than a distance (the shortest distance) from the upper surface 44a of the top plate portion 44 to the lowest end of the folded portion 102c.

Further, the leading end plate portion 104 of the floor panel 100 is arranged in a left side (an outer side) in FIG. 10 in relation to the side plate portion 102.

Therefore, in the floor panel 100, the leading end angled portion 104a of the leading end plate portion 104 corresponding to the leading end angled portion 16c of the side plate portion 16 in the conventional floor panel 2 is arranged closer to the upper surface 44a of the top plate portion 44 than the lowest end of the folded portion 102c, and is arranged in the outer side of the side plate portion 102 which is folded perpendicularly from the top plate portion 44 so as to be connected thereto.

Further, in the floor panel 40, the folded portion 102c is formed in a portion corresponding to the lower end portion of the side plate portion 16 in which the leading end angled portion 16c of the conventional floor panel 2 in FIG. 18 is formed, the folded portion 102c being formed approximately as a U-shaped form in its cross sectional shape and being formed as a circular arc curved shape in its outer profile, as shown in FIG. 10.

As a result, in the floor panel 100 according to the present embodiment, since the cable such as the wiring arranged in the space in relation to the floor surface 3 does not come into contact with the leading end angled portion 104a of the leading end plate portion 104, it is possible to prevent the cable from being damaged so as to cause an accident.

Further, in the floor panel 100 according to the present embodiment, since the shape thereof including the folded portion 102c of the side plate portion 102 is formed by press molding the plate-like member cut into a predetermined shape as it is, the structure thereof is simple and it is possible to prevent a manufacturing cost from being increased.

Accordingly, on the basis of the floor panel 100 according to the present embodiment, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged by the contact with the leading end angled portion 104a of the leading end plate portion 104, and it is possible to prevent the manufacturing cost from being increased on the basis of the simple structure, in the same manner as the floor panel 40 according to the first embodiment mentioned above.

Further, on the basis of the floor panel 100 according to the present embodiment, since the folded portion 102c of the side plate portion 102 is formed, and a section modulus and a geometrical moment of inertia become higher, it is possible to suppress deflection of the floor panel 100.

FIG. 11 is a view which is referred for describing a floor panel 110 according to an eighth embodiment of the present invention.

The floor panel 110 according to the present embodiment is different from the floor panel 100 according to the seventh embodiment mentioned above in a point that a side plate portion 112 and a leading end plate portion 114 as shown in FIG. 11 are provided in place of the side plate portion 102 and the leading end plate portion 104 in the seventh embodiment mentioned above.

Further, a step surface 112a, a protruding portion 112b and a folded portion 112c of the side plate portion 112 and a leading end angled portion 114a of the leading end plate portion 114 in the floor panel 110 are the same as the step surface 102a, the protruding portion 102b and the folded portion 102c of the side plate portion 102 and the leading end angled portion 104a of the leading end plate portion 104 according to the seventh embodiment mentioned above, except a point that respective positional relationships are somewhat different according to the shape of the side plate portion 112.

In other words, the side plate portion 112 of the floor panel 110 is different from the side plate portion 102 according to the seventh embodiment in a point that the side plate portion 112 is folded from an edge portion of the top plate portion 44 and is formed in a curved manner so that a lower end portion thereof comes to a right side in the drawing (closer to the center of the top plate portion 44) than an upper end portion thereof, as shown in FIG. 11.

Further, in the leading end plate portion 114 of the floor panel 110, since the protruding portion 112b of the side plate portion 112 is folded in the folded portion 112c, a leading end portion having the leading end angled portion 114a in an opposite side to an end portion connected to the folded portion 112c is arranged so as to be away from the upper surface 44a of the top plate portion 44 at a distance which is shorter than a distance (the shortest distance) from the upper surface 44a of the top plate portion 44 to the lowest end of the folded portion 112c.

Further, the leading end plate portion 114 of the floor panel 110 is arranged in a left side (an outer side) in FIG. 11, and is arranged in a right side in the drawing (closer to the center portion of the top plate portion 44) than a left end portion in FIG. 11 of the top plate portion 44.

Therefore, in the floor panel 110, the leading end angled portion 114a of the leading end plate portion 114 corresponding to the leading end angled portion 16c of the side plate portion 16 in the conventional floor panel 2 is arranged closer to the upper surface 44a of the top plate portion 44 than the lowest end of the folded portion 112c, and is arranged in the outer side of the side plate portion 112 which is folded from the top plate portion 44 so as to be connected thereto.

Further, in the floor panel 110, the folded portion 112c is formed in a portion corresponding to the lower end portion of the side plate portion 16 in which the leading end angled portion 16c of the conventional floor panel 2 in FIG. 18 is formed, the folded portion 112c being formed approximately as a U-shaped form in its cross sectional shape and being formed as a circular arc curved shape in its outer profile, as shown in FIG. 11.

As a result, in the floor panel 110 according to the present embodiment, since the cable such as the wiring arranged in the space in relation to the floor surface 3 does not come into contact with the leading end angled portion 114a of the leading end plate portion 114, it is possible to prevent the cable from being damaged so as to cause an accident.

Further, in the floor panel 110 according to the present embodiment, since the shape thereof including the folded portion 112c of the side plate portion 112 is formed by press molding the plate-like member cut into a predetermined shape as it is, the structure thereof is simple and it is possible to prevent a manufacturing cost from being increased.

Accordingly, on the basis of the floor panel 110 according to the present embodiment, it is possible to prevent the cable such as the wiring arranged in the space in relation to the floor surface 3 from being damaged by the contact with the leading end angled portion 114a of the leading end plate portion 114, and it is possible to prevent the manufacturing cost from being increased on the basis of the simple structure, in the same manner as the floor panel 100 according to the seventh embodiment mentioned above.

Further, on the basis of the floor panel 110 according to the present embodiment, since the folded portion 112c of the side plate portion 112 is formed, and a section modulus and a geometrical moment of inertia become higher, it is possible to suppress deflection of the floor panel 110.

The present invention is not limited only to the embodiments mentioned above, but can be variously modified in relation to the floor panel and the free access floor using the floor panel, within a range which can achieve the object of the present invention.

For example, in the floor panel 40 according to the first embodiment, the folded portion 46c is formed in the lower end portion of the protruding portion 46b by being folded in the protruding portion 46b of the side plate portion 46, however, the side plate portion 46 may be folded over a whole in a length direction of the side plate portion 46 at a height position above the step surface 46a of the side plate portion 46, and a folded portion may be formed in a lower end portion of the side plate portion 46. This point and the following points can be applied in the same manner to the floor panels according to the other embodiments.

Further, in the floor panel 40 according to the first embodiment mentioned above, the cross sectional shape of the length center portion in each of the side plate portion 46 and the leading end plate portion 48 is formed as one linear shape, however, is not limited to this shape, but may be folded in the midstream of the length center portion and the cross sectional shape of the length center portion may be formed as a zigzag line shape that a plurality of straight lines are connected in respective end portions, or the cross sectional shape of the length center portion may be formed as a curved shape having one circular arc or a plurality of circular arcs.

Further, in the floor panel 40 according to the first embodiment mentioned above, the leading end portion having the leading end angled portion 48a in the leading end plate portion 48 is arranged so as to be away from the upper surface 44a of the top plate portion 44 at the distance which is shorter than the distance (the shortest distance) from the upper surface 44a of the top plate portion 44 to the lowest end of the folded portion 46c, however, is not limited to this shape, but may be arranged so as to be away from the upper surface 44a of the top plate portion 44 at a distance which is longer than the distance from the upper surface 44a of the top plate portion 44 to the lowest end of the folded portion 46c.

Further, the floor panel 40 according to the first embodiment mentioned above is structured such as to construct the free access floor 42 together with the support tables 6 which are provided in a rising manner on the floor surface 3 via the connection member 8, however, may be structured such as to have not connection member 8, whereby the support tables 6 may be provided in a rising manner directly on the floor surface 3.

Further, in the floor panel 40 according to the first embodiment mentioned above, the end portion in the length direction of the side plate portion 46 in which the step surface 46a is fitted to the groove portion 6b of the support table 6 from the above and the back surface of the top plate portion 44 comes into contact with the upper end surface 6a of the support table 6, whereby the floor panel 40 is detachably supported to the predetermined height position on the floor surface 3, however, the floor panel is not limited to this embodiment, but may be structured as long as it is supported to the support table 6.

Further, in the support table 6 according to the first embodiment mentioned above, the rib 6c is formed in the length midstream portion of the groove portion 6b, however, the support table may be structured such as to have not rib 6c as long as the end portion of the side plate portion 46 in the floor panel 40 can be fitted into the groove portion 6b of the support table 6.

Claims

1. A floor panel comprising: a plate-like top plate portion which has a plane portion and four edges in a peripheral portion thereof;a plurality of side plate portions which are formed by being folded from said four edges; andthe floor panel being supported to a support table so as to construct a free access floor,wherein said side plate portions are folded and folded portions are formed in lower end portions of said side plate portions.

2. The floor panel according to claim 1, wherein leading end plate portions are formed in said side plate portions so as to be connected via said folded portions, and wherein leading end portions in an opposite side to end portions connected to said folded portions of said leading end plate portions are arranged at positions closer to a center portion of said plane portion in relation to said folded portions.

3. A floor panel comprising: a plate-like top plate portion which has a plane portion and four edges in a peripheral portion thereof;a plurality of side plate portions which are formed by being folded from said four edges; andthe floor panel being supported to a support table so as to construct a free access floor,wherein a round process is applied to lower end portions of said side plate portions and curved surface portions are formed.

4. A floor panel comprising: a plate-like top plate portion which has a plane portion and four edges in a peripheral portion thereof;a plurality of side plate portions which are formed by being folded from said four edges; andthe floor panel being supported to a support table so as to construct a free access floor,wherein a chamfer process is applied to lower end portions of said side plate portions and inclined surface portions which are inclined to side surfaces and/or lower end surfaces of said side plate portions are formed.