JP6312366B2 - Underfloor beam material and underfloor beam support structure - Google Patents

Description

  The present invention relates to an underfloor beam material and a support structure for the underfloor beam material, and particularly to a steel underfloor beam material and a support structure for a steel underfloor beam material.

  As a member for supporting the floor board or the like, there is an underfloor beam material such as a joist or an overhang arranged at the lower part of the floor board. The large fork is arranged on a bundle arranged so as to extend vertically upward at a predetermined interval above the soil formed by the concrete as the foundation. In addition, a plurality of joists are arranged in a lattice pattern on the fork. And these large pulls and joists support the floor board etc. which comprise the floor of a room.

  In the past, wood was often used as a material for large draws. However, steel products are also used recently. The steel pulling is formed by bending a steel plate having a predetermined thickness from the viewpoint of weight reduction and low cost. Such a steel fore is so-called hollow.

  The steel fore is disclosed in Japanese Patent Laid-Open No. 2000-73527 (Patent Document 1).

JP 2000-73527 A

  Since the underfloor beam material is used as a member for supporting a floor board or the like, a high strength is required as well as a restoring force against bending. About the steel-made fork disclosed in Patent Document 1, the outer shape is substantially rectangular. And the long side which comprises a rectangular shape is arrange | positioned so that it may extend in a perpendicular direction. By carrying out like this, it can be used in the direction with strong intensity | strength in substantially rectangular steel drawing. That is, high strength can be ensured by using steel pulling as a strong shaft.

  However, when the steel pull is used in this way, the vertical length occupied by the steel pull itself becomes long. If it does so, the living space which a floor board etc. will be arrange | positioned on steel pulling will become narrow. Specifically, since the ceiling height of a room is often determined by itself, if a floorboard or the like is installed high relative to the soil, the vertical length of the room that can be secured as a living space is shortened. End up. In particular, in recent years, it is required to secure a wider living space, and there is a demand to avoid using the strong shaft as much as possible. In this case, if the above-described steel pulling is simply used as a weak shaft so that the short sides constituting the rectangular shape extend in the vertical direction, a wide living space can be secured. However, in this case, the strength required as a big draw is insufficient. Although it is conceivable to increase the thickness of the steel sheet to ensure the strength, it is not preferable because it increases the material cost in addition to increasing the weight.

  An object of the present invention is to provide an underfloor beam material capable of maintaining high strength and ensuring a wide living space while realizing low cost.

  Another object of the present invention is to provide an underfloor beam support structure capable of maintaining high strength and securing a wide living space while realizing low cost.

The underfloor beam material according to one embodiment of the present invention is a steel underfloor beam material formed by bending a steel plate into a roll shape so that its outer shape is substantially rectangular. In the underfloor beam material, both ends of the folded steel plate are positioned on the long side on one side constituting the rectangular shape. Here, when the plate thickness of the steel sheet and _{t 1,} the radius of curvature of the four corner portions constituting the rectangular shape, respectively, is 1.0 t ₁ or 2.4 T ₁ less.

According to such an underfloor beam material, both ends of the folded steel plate are located on the long side of one side constituting the rectangular shape, and it is used as a so-called weak shaft, so that the vertical direction as the underfloor beam material is used. The length can be shortened. In this case, when the thickness of the steel sheet and t _1, respectively curvature of the four corners that constitute the rectangular radius, because it is 1.0 t ₁ or 2.4 T ₁ or less, when used as the weak axis Tsukai Even if it exists, a possibility that the fall of productivity may be reduced and intensity | strength can be maintained high. Therefore, according to such an underfloor beam material, high strength can be maintained and living space can be secured widely while realizing low cost. Here, the underfloor beam material refers to a member that is disposed under the floor and used as a beam.

  Moreover, you may comprise so that both ends may be crimped and connected.

  Moreover, you may comprise so that the rib dented inward may be provided in the long side of the other side which comprises rectangular shape.

  Further, a plurality of ribs may be provided.

Further, the thickness of the steel sheet _may be configured to have a relationship of t 1 <1.6 mm.

  Moreover, you may comprise so that it may be formed by roll forming.

  Moreover, you may comprise so that an overdraw or joist may be included.

  In another aspect of the present invention, the underfloor beam support structure includes any of the above-described underfloor beam members and a support portion that supports the underfloor beam material from the vertically lower side.

In yet another aspect of the present invention, the support structure for the underfloor beam material includes a hollow steel underfloor beam material whose outer shape is substantially rectangular, and a support for supporting the underfloor beam material from the vertically lower side. A part. The underfloor beam material is provided such that the long side of the rectangular shape faces the support portion. Here, if the thickness of the steel sheet and _{t 1,} the radius of curvature of the four corner portions constituting the rectangular shape, respectively, is 1.0 t ₁ or 2.4 T ₁ less.

  According to the support structure for the under-floor beam having such a configuration, it is possible to maintain high strength and secure a wide living space while realizing low cost.

According to such an underfloor beam material, both ends of the folded steel plate are located on the long side of one side constituting the rectangular shape, and it is used as a so-called weak shaft, so that the vertical direction as the underfloor beam material is used. The length can be shortened. In this case, when the thickness of the steel sheet and t _1, respectively curvature of the four corners that constitute the rectangular radius, because it is 1.0 t ₁ or 2.4 T ₁ or less, when used as the weak axis Tsukai Even if it exists, intensity | strength can be maintained high. Therefore, according to such an underfloor beam material, it is possible to secure a wide living space while maintaining high strength.

It is a perspective view which shows the external appearance of the steel large drawing as an underfloor beam material which concerns on one Embodiment of this invention. It is the figure which looked at the steel drawing shown in FIG. 1 from the longitudinal direction of the steel drawing shown by the arrow II in FIG. It is the schematic which shows a part of steel support structure provided with the steel guide shown in FIG. It is the figure which looked at the support structure of the steel large drawing shown in FIG. 3 from the direction of arrow IV in FIG. It is a figure which shows the steel drawing according to other embodiment of this invention. It is a figure which shows the steel drawing according to further another embodiment of this invention. It is the schematic which shows a compression test apparatus. It is the figure which looked at the compression test apparatus shown in FIG. 7 from the direction of arrow VIII in FIG. It is a figure which shows the conventional steel drawing.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an appearance of a steel pulling as an underfloor beam material according to an embodiment of the present invention. FIG. 2 is a view of the steel drawing shown in FIG. 1 as viewed from the longitudinal direction of the steel drawing shown by an arrow II in FIG. FIG. 3 is a schematic view showing a part of the support structure of the underfloor beam member having the steel pulling shown in FIG. FIG. 4 is a view of the steel pulling support structure shown in FIG. 3 as viewed from the direction of arrow IV in FIG.

  Referring to FIGS. 1 to 4, a steel pulling 11 according to an embodiment of the present invention is a square member extending in the longitudinal direction and is hollow. The length of the steel pull 11 is about several meters. The steel draw 11 has a shape that extends straight in the longitudinal direction.

As for the shape of the steel pull 11, the outer shape is substantially rectangular when viewed from the longitudinal direction of the steel pull 11. The steel fork 11 is roughly composed of a pair of long sides 12a and 12b and a pair of short sides 13a and 13b. The pair of long sides 12a and 12b and the pair of short sides 13a and 13b are provided to face each other. Long side 12a, the length of 12b are the same, represented by the length _{L 1} in FIG. Short side 13a, the length of 13b are also the same, represented by the length _{L 2} in FIG. Note that the length _{L 1} is, for example, 100 mm is selected, the length _{L 2} is, for example, 50 mm is selected. And the external shape of the steel large drawing 11 is a structure which has the four corner | angular parts 14a, 14b, 14c, and 14d which comprise rectangular shape. Specifically, a corner 14a is formed between the long side 12a on one side and the short side 13a on one side, and the corner 14b is formed between the long side 12b on the other side and the short side 13a on the one side. The corner 14c is formed between the other long side 12b and the other short side 13b, and the corner 14d is formed between the one long side 12a and the other short side 13b. The In addition, about the steel drawing 11, the external shape of the cross section at the time of cut | disconnecting by the plane extended perpendicularly | vertically to a longitudinal direction is the same as the external shape shown in FIG.

The steel draw 11 is formed by bending a single flat steel plate. Specifically, it is formed by roll forming a single flat plate so that the above-described outer shape is substantially rectangular. Specifically, one rectangular flat steel plate is gradually bent into a rectangular shape so as to form four corners by roll forming. By comprising in this way, the steel drawing 11 whose outer shape is substantially rectangular shape can be manufactured efficiently, and cost reduction can be aimed at. In this case, 1.2 mm is selected as the plate thickness t ₁ of the steel plate used when the steel draw 11 is manufactured. Here, the curvature radii of the corner portions 14a to 14d are preferably as large as possible from the viewpoint of reducing the amount of wear of the members used for roll forming in consideration of productivity.

The ends 15a and 15b of one steel plate are joined by caulking. Specifically, for the caulking portion 16, one end 15a of the steel plate is folded back, the other end 15b of the steel plate is folded, and the folded portions of the end portions 15a and 15b are engaged. Is provided. The caulking portion 16 is provided at the center of the long side 12a in the left-right direction of the paper surface shown in FIG. The caulking portion 16 is provided by bending both end portions 15a and 15b so as to protrude inward in the hollow steel drawing 11. The length in the horizontal direction of the caulking portion 16 shown by the length L ₃ in FIG. 2, for example, approximately 9.4mm is chosen. By comprising in this way, both ends 15a and 15b can be connected reliably.

  As shown in FIG. 3, the caulking portion 16 in which the end portions 15a and 15b are joined to each other is disposed on the long side 12a on one side constituting a rectangular shape. That is, both end portions 15a and 15b are positioned on the long side 12a on one side constituting a rectangular shape. In addition, the outer side surface 17a of the long side 12a on one side constituting the rectangular shape is configured to be flat.

  Of the steel pull 11, the long side 12b on the other side constituting the rectangular shape is provided with upper surface ribs 18a and 18b partially projecting toward the hollow inner side. The first upper surface rib 18a is provided so as to protrude in a trapezoidal shape toward the inner side of the hollow steel drawing 11. Specifically, the first upper surface rib 18a is inclined from the outer surface 17b on the other side and extends so as to approach each other, and the first and second inclined portions 19b, It is comprised from the flat part 20a which connects the edge part of inclination part 19a, 19b. In the case shown in FIG. 2, the outer surface 21a constituting the flat portion 20a is provided in parallel with the outer surface 17b. Similarly, the second upper surface rib 18b includes a first inclined portion 19c, a second inclined portion 19d, and a flat portion 20b.

For example, about 28.5 mm is selected for each of the length L ₄ in the left-right direction of the first upper surface rib 18a and the length L ₅ in the left-right direction of the second upper surface rib 18b. Further, as shown in FIG. 2, the first and second upper surface ribs 18a and 18b are, when viewed from the longitudinal direction, the center 22a in the horizontal direction of the paper surface of the steel pulling 11 shown by the one-dot chain line in FIG. The center is provided so as to be symmetrical. The right and left direction between the first top rib 18a and the second top rib 18b indicated by the length L ₆ in FIG. 2, for example, about 20mm is selected. The first upper surface rib 18a is provided so as to extend in the longitudinal direction. Of the first top rib 18a, the protrusion amount of the protruding inwardly from the outer surface 17b of the long side 12b is represented by the length L ₇ in FIG. The second upper surface rib 18b has the same configuration. The length _{L 7,} for example, 2.4 mm is selected.

In the steel large fork 11, a short side 13a on one side constituting a rectangular shape is provided with a first side rib 23a, a part of which protrudes inward. Further, a second side rib 23b, a part of which protrudes inward, is provided on the other short side 13b constituting the rectangular shape. The configuration of the first side rib 23a will be described. The first side rib 23a is also provided so as to protrude in a trapezoidal shape toward the inner side of the hollow steel pulling 11. That is, the first side rib 23a is inclined from the outer surface 24a on one side and extends so as to approach each other, the second inclined portion 25a, and the first and second inclined portions 25b. , 25a, and a flat portion 26a that connects the end portions of each other. In the case shown in FIG. 2, the outer surface 27a constituting the flat portion 26a is provided in parallel with the outer surface 24a. Similarly, the second side surface rib 23b includes a first inclined portion 25d, a second inclined portion 25c, and a flat portion 26b. The second side rib 23b is provided so as to face the first side rib 23a. The first and second side ribs 23 a and 23 b are respectively provided in the center of the steel pull 11 in the vertical direction. Specifically, the short side 13a on one side provided with the first side rib 23a and the short side 13b on the other side provided with the second side rib 23b are indicated by a two-dot chain line in FIG. It is comprised so that it may become vertically symmetrical centering | focusing on the center 22b of the up-down direction of the steel large drawing 11. FIG. The first and second side ribs 23a, respectively the length _{L 8} in the vertical direction 23b, for example, 20 mm is selected. Further, in FIG. 2 of the short sides 13a shown by the length L ₉ projecting amount which protrudes inwardly of the first side ribs 23a from the outer surface 24a, and the short side 13b from the outer surface 24b second About 1.2 mm is selected about the protrusion amount which protrudes inward of the side rib 23b.

  Next, the structure of the steel large drawing support structure 31 that supports the steel large drawing 11 will be described. The steel pulling support structure 31 includes the steel pulling 11 having the above-described configuration and a bundle 32 as a support portion that supports the steel pulling 11 from the vertically lower side. The bundle 32 may be made of steel. The bundle 32 is configured so that its length can be changed in the vertical direction.

  The bundle 32 has a so-called bar shape, and is disposed on a soil 33 formed by concrete or the like indicated by a one-dot chain line in FIGS. 3 and 4. Specifically, one end of the bundle 32, that is, the lower end 34a is attached to the top of the dirt 33 so as to extend in the vertical direction. Then, the steel pulling 11 is disposed on the other end 34 b of the bundle 32, specifically, on the upper end 34 b of the bundle 32. Specifically, a large receiving tool 35 that receives the steel pulling 11 is attached to the upper end 34 b of the bundle 32, and the long side 12 a on one side of the steel pulling 11 is placed on the large receiving tool 35. Are attached to face each other. In this case, it arrange | positions so that the above-mentioned crimping | crimped part 16 comprised from the both ends of the bent steel plate may be located in the large drawing tool 35 side of this steel large drawing 11. FIG. Note that the large receiving tool 35 and the steel large drawing 11 may be fixed using screws or the like. In this case, the outer side surface 17a of the long side 12a on one side is flat, and the upper side surface 36 of the large receiving tool 35 is also flat, so that the contact area when each member is brought into contact is widened. Thus, when a large amount of load is received, an increase in local load can be reduced.

  That is, the steel pulling 11 is used by using a so-called weak shaft by arranging the long side 12a on one side on the vertically lower side. By doing so, it is possible to shorten the length in the vertical direction as the underfloor beam by using the steel pulling 11 as the underfloor beam as a so-called weak shaft. Therefore, the floor level can be set low, and a large living space can be secured. In this case, specifically, a space as large as 50 mm can be secured in the height direction as compared with the case where the shaft is used as a strong axis.

  A plurality of bundles 32 are provided at predetermined intervals. And the one steel drawing 11 is provided by the plurality of bundles 32 so as to be supported from the lower side. The plurality of bundles 32 are arranged in the front and back direction on the paper surface in the case shown in FIG. 3, and in the left and right direction on the paper surface in the case shown in FIG.

Here, the steel Obiki 11, when the plate thickness of the steel sheet and _{t 1,} 4 one corner 14a constituting a rectangular, 14b, 14c, the curvature of 14d radius _{R 1, R 2, R 3} , R 4 Are configured to be 1.0 t ₁ or more and 2.4 t ₁ or less, respectively. Specifically, each of the curvature radius of curvature of the four corner portions 14a~14d constituting the rectangular radius _{R 1, R 2, R 3} , when the _{R 4, 1.0t 1 ≦ R 1} ≦ 2.4t 1 1.0t ₁ ≦ R ₂ ≦ 2.4t ₁ , 1.0t ₁ ≦ R ₃ ≦ 2.4t ₁ , and 1.0t ₁ ≦ R ₄ ≦ 2.4t ₁ . Here, the radius of curvature _R 1 to R _4, the radius of curvature of the inner surface of the corner portion 14a to 14d. In this case, specifically, the plate thickness t1 of the steel plate is 1.2 mm, and the curvature radii R _{1 to} R ₄ are 2.4 mm, so the curvature radii R _{1 to} R ₄ are it is two times the thickness _{t 1.}

By comprising in this way, even if it is a case where it uses as a weak shaft use, intensity | strength can be maintained high. In other words, the radii of curvature R _{1 to} R ₄ of the corner portions 14 a to 14 d are set to 2.4 t ₁ or less, and the strength can be ensured. Moreover, the radius of curvature _R 1 to R ₄ corners 14a~14d as 1.0 t ₁ or more, to reduce the amount of wear of the members by roll forming process or the like, it is possible to reduce the risk of reduced productivity. Therefore, according to such a steel draw 11, the high strength can be maintained and the living space can be secured widely while realizing low cost. Note that the radius of curvature _R 1 to R ₄ corners 14a to 14d, preferably, 2.0 t ₁ the following are employed.

  In addition, about said embodiment, it was set as the structure which provides the two upper surface ribs 18a and 18b, and the length of the left-right direction which protrudes inward, respectively, ie, the width | variety of the upper surface ribs 18a and 18b, was 28.5 mm. However, the width of the upper surface rib may be narrower than the above-described interval. FIG. 5 is a diagram showing the steel forking in this case, and corresponds to FIG.

  Referring to FIG. 5, a steel pulling 41 according to another embodiment of the present invention has a substantially rectangular outer shape, and includes a pair of long sides 42 a and 42 b and a pair of short sides 43 a and 43 b. It is composed of In addition, the outer shape of the steel pulling 41 is a configuration having four corners 44a, 44b, 44c, and 44d that form a rectangular shape. The steel pulling 41 is provided on the long side 42a side on one side, and the two ends 45a, 45b of the steel plate are joined to each other and the long side 42b side on the other side. It is the structure provided with upper surface rib 47a, 47b and two side surface ribs 48a, 48b provided in a pair of short side 43a, 43b side.

Here, the length in the horizontal direction of the two top ribs 47a, 47b shown by the length _{L 10} in FIG. 5, 24.5 mm are selected. Other configurations are the same as those shown in FIG. That is, the lateral direction of the distance between the first top rib 47a and the second top rib 47b indicated by the length L ₁₁ in FIG. 5, about 20mm is selected. Further, the thickness _{t 1} of the steel sheet is 1.2 mm, respectively the radius of curvature of the corners 44a~44d is a 2.4 mm, which is twice the thickness of the steel plate _{t 1.} You may comprise in this way.

  In the above embodiment, the two upper surface ribs are provided on the other long side. However, the present invention is not limited to this, and one upper surface rib may be provided, or no upper surface rib may be provided. It is good. Furthermore, it is good also as a structure which does not provide a side rib. FIG. 6 is a view showing the steel forking in this case and corresponds to FIGS. 2 and 5.

Referring to FIG. 6, a steel pulling 51 according to still another embodiment of the present invention has a substantially rectangular outer shape, and includes a pair of long sides 52a and 52b, a pair of short sides 53a, 53b. In addition, the outer shape of the steel draw 51 is a configuration having four corners 54a, 54b, 54c, 54d that form a rectangular shape. The steel draw 51 is provided with a caulking portion 56 in which both end portions 55a and 55b of the steel plate are joined to each other on the long side 52a side on one side, but the long side 52b on the other side is flat. The upper surface rib is not provided. Further, the pair of short sides 53a and 53b is also flat and does not have the side ribs described above. About another structure, it is the same as steel steel drawing shown in above-mentioned FIG. 2, FIG. That is, the thickness _{t 1} of the steel sheet is 1.2 mm, respectively the radius of curvature of the corners 54a~54d is a 2.4 mm, which is twice the thickness _{t 1} of the steel sheet. You may decide to comprise in this way.

  Next, the strength of such steel pullings 11, 41, 51 will be described. 7 and 8 are schematic views showing a compression test apparatus for testing the strength of steel pulling. FIG. 8 is a view of the compression test apparatus shown in FIG. 7 as viewed from the direction of arrow VIII. With reference to FIG. 7 and FIG. 8, the configuration of the compression test apparatus and the test method will be briefly described.

  The compression test apparatus 61 includes a base portion 63 such as H-shaped steel on which a steel pulling 62 as a test body is placed, a force applying jig 64 disposed on the steel pulling 62, and a force applying force. A pin jig 65 disposed on the jig 64 and a compression loading plate 66 as a load cell disposed on the pin jig 65 are provided.

Regarding the compression test, first, a steel pulling 62 as a test body is placed on the base portion 63. In this case, it arrange | positions so that the side in which the caulking part of the steel large drawing 62 was formed may become an upper side. Next, the applying jig 64, the pin jig 65, and the compression loading plate 66 are sequentially arranged on the steel draw 62. Here, the applying jig 64 is a member corresponding to the large receiving tool provided in the bundle in the steel large drawing support structure 31 described above. Incidentally, the width of the pressurizing force jig 64 shown in the length L ₁₂ of figure, 80 mm corresponding to a large underwriting tool provided in flux is selected.

  After this arrangement, a load is gradually applied to the compression loading plate in the direction indicated by the arrow VII in FIG. In this case, first, a preliminary load is applied up to 1500 N (Newton), and the presence or absence of deformation or damage is checked. Thereafter, the pressure is continuously applied to 4306N, and the elastic displacement is calculated after unloading. As for the value of the elastic displacement, a lower value is better. In addition, check for deformation and damage. The applied force of 4306N was set as the set load 1. Thereafter, the force is applied again, and the force is continuously applied to 6459 N. After the unloading, the elastic displacement is calculated. The applied force of 6459N was set as the set load 2. Then, apply force again and check the maximum load. For this maximum load, a higher value is better. In addition, the speed of the applied force during the test is about 0.05 mm / second. For measurement, a universal testing machine and a dial gauge were used.

  In addition, the case of the steel drawing 11 shown in FIG. 1 and FIG. 2 is given as Example 1, the case of the steel drawing 41 shown in FIG. 5 is given as Example 2, and the steel drawing 51 shown in FIG. This case is given as Example 3. The results of these compression tests are shown in Table 1 below.

Further, as Comparative Example 1, the following was used. FIG. 9 is a view showing a conventional steel drawing, and corresponds to FIG. Referring to FIG. 9, the conventional steel pulling 101 has a substantially rectangular outer shape, and includes a pair of long sides 102a and 102b and a pair of short sides 103a and 103b. In addition, the outer shape of the steel pulling 101 is a configuration having four corner portions 104a, 104b, 104c, and 104d that form a rectangular shape. The steel pulling 101 is provided on the long side 102a side of one side and is provided with a caulking part 106 where both ends 105a and 105b of the steel plate are joined together, but the long side 102b on the other side is flat. The pair of short sides 103a and 103b is also flat. The thickness _{t 1} of the steel sheet is 1.2 mm, the radius of curvature _R 5 of the corner _{104a~104d, R 6, R 7,} R 8 each is 3.3 mm. That is, the radius of curvature _R 5 to R of the corner portion 104 a to 104 d _8, respectively, is 2.8 times the thickness _{t 1} of the steel sheet.

  With reference to Table 1, from the viewpoint of the elastic displacement of the set load 1, the elastic displacement of the set load 2, and the maximum load, Examples 1 to 3 were acceptable levels as products. Further, with respect to the set load 1, in Comparative Example 1, the elastic displacement was 0.785 mm. On the other hand, in Example 1, the elastic displacement was 0.520 mm, which was about 66.2% of that in Comparative Example 1. Moreover, about Example 2, the elastic displacement was 0.466 mm, and it was settled in about 59.3% with respect to the comparative example 1. Further, in Example 3, the elastic displacement was 0.659 mm, which was about 83.9% of that of Comparative Example 1.

  With respect to the set load 2, in Comparative Example 1, the elastic displacement was 1.000 mm. On the other hand, in Example 1, the elastic displacement was 0.639 mm, which was about 63.9% of that in Comparative Example 1. Moreover, about Example 2, the elastic displacement was 0.580 mm, and was settled at about 58.0% with respect to the comparative example 1. Moreover, about Example 3, the elastic displacement was 0.782 mm, and it was settled in about 78.2% with respect to the comparative example 1.

  The maximum load was 15398 N in Comparative Example 1. On the other hand, about Example 1, it was 17664N and it was a ratio of 114.7% with respect to the comparative example 1. Moreover, about Example 2, it was 17840N and it was a ratio of 115.9% with respect to the comparative example 1. Moreover, about Example 3, it was 18077N, and it was a ratio of 117.4% with respect to the comparative example 1.

  From these results, for both the set load 1 and the elastic displacement of the set load 2, Example 1 to Example 3 are all better than Comparative Example 1, and Example 2, Example 1, It was understood that the results were favorable in the order of Example 3. Moreover, about the maximum load, Example 1-Example 3 were all favorable with respect to the comparative example 1, and it has been grasped | ascertained that it is favorable in order of Example 3, Example 2, and Example 1. FIG. That is, it is considered that the strength can be maintained higher by providing a plurality of ribs and by configuring the ribs to be relatively long.

  As described above, according to such steel pulling and the steel pulling support structure, it is possible to maintain high strength and secure a wide living space while realizing low cost.

  In the above embodiment, the end portions of the steel plates are joined by caulking. However, the present invention is not limited to this. For example, the end portions may be joined by welding. The ends need not be joined together.

Here, as a support structure for steel pulling, the steel pulling is provided with a hollow steel pulling whose outer shape is substantially rectangular, and a support part for supporting the steel pulling from the vertically lower side. are each long side which constitutes the rectangular shape, and so disposed facing the support unit, when the thickness of the steel sheet and t _1, the radius of curvature of the four corner portions constituting the rectangular shape, 1.0 t ₁ or 2.4 T ₁ may be configured to or less. In other words, even without constituting a joint joining the ends, such as square pipes, the above-described configuration, i.e., the plate thickness of the steel sheet and t _1, the curvature of the four corner portions constituting the rectangular As a configuration in which the radii are set to 1.0 t ₁ or more and 2.4 t ₁ or less, respectively, by using as a weak shaft, high strength can be maintained and a large living space can be secured while realizing low cost.

In the above-described embodiment, the steel sheet thickness t ₁ is configured to be 1.2 mm. However, the present invention is not limited to this, and the steel sheet thickness t ₁ <1.6 mm. You may comprise. By configuring in this way, the material cost can be more reliably reduced and the weight can be reduced.

  In the above embodiment, when the steel sheet is folded into a roll shape, the roll forming process is performed. However, the present invention is not limited thereto, and the outer shape of the steel sheet is folded into a roll shape by another method. A substantially rectangular shape may be used.

In the above-described embodiment, the four corners constituting the rectangular shape have the same radius of curvature. However, the present invention is not limited to this, and each of the four corners has a different radius of curvature. May be. That is, any curvature radius may be used as long as it satisfies the relationship of 1.0 t ₁ or more and 2.4 t ₁ or less in the relationship between the thickness t _{1 of the} steel plate and the curvature radius of each corner. .

  Further, in the above embodiment, the steel pulling is substantially rectangular, but the long side on one side has a trapezoidal shape with a slightly longer configuration or a slightly shorter configuration than the long side on the other side. Also applies.

  In the above-described embodiment, the steel underbrush is provided as the underfloor beam material. However, the present invention is not limited thereto, and examples of the underfloor beam material include joists and other members used under the floor.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The underfloor beam material and the support structure for the underfloor beam material according to the present invention are effectively used when maintaining high strength and ensuring a large living space while achieving low cost.

  11, 41, 51, 62, 101 Steel draw, 12a, 12b, 42a, 42b, 52a, 52b, 102a, 102b long side, 13a, 13b, 43a, 43b, 53a, 53b, 103a, 103b short side, 14a, 14b, 14c, 14d, 44a, 44b, 44c, 44d, 54a, 54b, 54c, 54d, 104a, 104b, 104c, 104d Corners, 15a, 15b, 34a, 34b, 45a, 45b, 55a, 55b, 105a, 105b end portion, 16, 46, 56, 106 crimped portion, 17a, 17b, 21a, 24a, 27a outer side surface, 18a, 18b, 47a, 47b upper surface rib, 19a, 19b, 19c, 19d, 25a, 25b, 25c, 25d inclined part, 20a, 20b, 26a, 26b flat part, 22a, 22 Center, 23a, 23b, 48a, 48b Side ribs, 31 Steel support structure, 32 Bundles, 33 Base, 35 Large receiving tool, 36 Upper surface, 61 Compression test device, 63 Base part, 64 Force treatment Tools, 65-pin jig, 66 compression loading plate.

Claims (7)

Such the outer shape is substantially rectangular, a steel underfloor beam member which is formed by bending into a roll a piece of the steel sheet four corners,
A pair of long sides and a pair of short sides constituting a rectangular shape ,
Long side of the one side positioned on the lower side in use state of the pair of long sides is connected both ends of the bent steel sheet crimped to include Takashime portion,
When the thickness of the steel sheet and _{t 1,} respectively the radius of curvature of said four corner portions constituting the rectangular shape state, and are 1.0 t ₁ or 2.0 t ₁ or less,
Of the pair of long sides, the other long side positioned on the upper side in the use state, and each of the pair of short sides are provided with ribs that partially project inward, and in use state In the underfloor beam material, the outer surface of the long side on the one side located on the lower side in FIG . In the long sides of the other side, the ribs are provided a plurality underfloor beam member of claim 1. The underfloor beam material according to claim 1 or 2 , wherein a thickness of the steel plate has a relationship of t ₁ <1.6 mm. Roll forming process is formed by, underfloor beam material according to any one of claims 1-3. The underfloor beam material according to any one of claims 1 to 4 , wherein the underfloor beam material includes large drawing or joist. Underfloor beam material according to any one of claims 1 to 5 ,
A support structure for an underfloor beam comprising a support portion for supporting the underfloor beam from a vertically lower side. Supporting the outer shape is such that a substantially rectangular shape, which supports the steel floor beams material formed by bending into a roll a piece of the steel sheet four corners, the underfloor beam member from a vertical lower side With
The underfloor beam material includes a pair of long sides and a pair of short sides constituting a rectangular shape ,
Of the pair of long sides, the long side on one side facing the support part includes a caulking part connected by caulking both ends of a bent steel sheet,
When the thickness of the steel sheet and _{t 1,} respectively the radius of curvature of said four corner portions constituting the rectangular shape state, and are 1.0 t ₁ or 2.0 t ₁ or less,
Each of the long side on the other side of the pair of long sides and each of the pair of short sides is provided with a rib that partially protrudes inward, and the outer surface of the long side on the one side Is a flat support structure for under-floor beams.

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