JP3055881B2 - Special steel bar - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaped steel having a special cross-sectional shape [Λ (lambda) shape], and is particularly suitable for use as a column member of a steel structure such as a rack. Related to various shaped steels.

[0002]

2. Description of the Related Art The most common shape steel is shown in FIG.
An equilateral angle iron as shown in (a). The standard equilateral angle iron has the secondary radius of section shown in FIG. That is, the secondary radius of the cross section of the equilateral angle iron is a flat elliptical shape, and the lengths of the short axis (weak axis) and the long axis (strong axis) are greatly different. Because of the large difference in strength between the strong axis and the weak axis, the use of angle iron alone as a structural member subjected to compressive or bending stress has many restrictions.

[0003] Table 1 shows that the thickness (T) of each side is 5 as an example.
mm, each side length (L) is 65 mm, an angle iron (a) and an equilateral square tube (hereinafter simply referred to as “permissible design force that allows for a safety factor”) having the same allowable compressive force (design allowable compressive force in consideration of the safety factor). Square tube)
(B) and calculated values of the cross-sectional properties of the special square steel (c, d) of the present invention described in detail below. FIG. 3 shows the angle iron (a), the square pipe (b), and the special square steel (c).
And the cross-sectional secondary radii thereof are shown in comparison.

[0004] As shown in Table 1, the secondary radius of section of the equilateral angle iron (a) is 2.51 cm at the maximum (iu) and 2.51 cm at the minimum (iv).
It is 1.28cm. The ratio of the minimum value to the maximum value, ie, i
If v / iu is defined as the "strength ratio," the equilateral angle iron has a striking ratio of 0.510. As shown in the table, the second moment of area also has a large difference between the maximum value (Iu) and the minimum value (Iv). On the other hand, a square tube does not have the above-mentioned axis. In other words, the strength ratio is 1. In FIG. 3, the secondary radius of the cross section of the square tube (b) (two-dot chain line) is a perfect circle. When these steel materials are used as pillars of a structure, they must be designed on the basis of a weak axis. Therefore, in the case of an equilateral angle steel, it is thicker and has a full width dimension (W in FIG. ₁ ) The larger one must be used.

[0005] For the above reasons, a square tube is ideal as a pillar material. However, the square pipe is manufactured by rolling and welding a steel strip, and there is a problem in that the production cost increases for an angle steel manufactured only by hot rolling. Further, as described later, it is inconvenient to transport or store a plurality of sheets in a pile. In this regard, angle irons are advantageous because they can be stacked as shown in Fig. 2 (b), but standard angle irons have an advantage in that when they are stacked due to the interference between the acute angle outside the intersection of the sides and the internal curved part, Gaps are created and the stacking is not stable. Shaped steel is often bundled together and cut to a fixed length with a band saw.
Cutting accuracy often deteriorates due to oblique cutting or the like.

[0006] Square pipes are used in various fields as structural members. One example of the use of such pipes is a nested rack. Since the section steel of the present invention is suitable for use as a column material of the nesting rack, the nesting rack will be described below.

In recent years, rationalization of physical distribution has become a major issue in the industrial world. In particular, the rationalization of storage and logistics of articles in narrow spaces is a matter of urgency. A nesting type rack proposed in Japanese Patent Publication No. 52-48554 and Japanese Utility Model Publication No. 61-6816 responds to such a demand.

FIG. 7 shows an example of a conventional nesting rack. Such racks have excellent stability when stacked and used for product storage in factories and warehouses, and can be compactly stored (nested) and transported when not in use. Have been used.

As shown in FIG. 7, a nested rack is provided with four pillars at four corners of a rectangle, and the distance (external method) between two pillars 11-1 located at the rear of the pillars is defined as follows. It is narrower than the distance between the two pillars 11-2 located at the front (inner method). The upper part is composed of a horizontal beam 15 connecting the rear columns and an upper rail 16 connecting the front and rear columns.

[0010] At the lower part of the rack, there is a bottom frame composed of a horizontal beam 13 and a vertical beam 14, and a bar 17 passed between them, on which articles to be stored are loaded. The lower rail 12 of the equilateral angle iron is attached to the vertical beam 14 of the bottom frame with the connecting member 19. The connecting member 19 is composed of the vertical beam 14 and the lower rail 12
Also serves as a spacer for forming a space 20 in which a forklift claw enters. Reference numeral 18 denotes a reinforcing member for ensuring the connection between the column 11-2 and the horizontal beam 13 of the bottom frame.

When the above-mentioned rack is used, racks having the same structure are stacked in several stages. FIG. 9A is a front view of the rail portion at that time. As shown, when the racks are stacked, the upper rail 16 of the lower rack fits with the lower rail 12 of the upper rack. As described in the real Sho 61-6816 Patent Publication supra, slightly smaller than the angle theta ₂ of the upper rail 16 the angle theta ₁ of the lower rail 12 (e.g., theta
₍₁ = 82 °, θ ₂ = 90 °, etc.) to ensure stability when superimposed.

As described above, the two pillars 11-1 at the rear of the rack
Is smaller than the distance between the two front pillars 11-2, so that when not in use, the second rack of the same shape is placed inside the first rack.
Can be stored by inserting the third rack sequentially inside the second rack, and so on, and storing it in a small space. A rack having such a structure is called a nesting rack, and such storage is called nesting.

Now, the pillar 11 of the nesting rack as described above.
-1 and 11-2 have conventionally been constituted by square tubes for the above-described reason. Therefore, even when nesting is performed when not in use, only the thickness of the pillar will inevitably protrude forward. FIG. 6A shows this state. 50 as a pillar
When a square tube of mm is used, nesting eight racks requires 50 (mm) x 7 = 350 (m) compared to a single rack.
m) only requires front space.

[0014]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a structure having a small difference between the maximum value and the minimum value of the secondary radius of the cross section, which can be used in place of a square tube as a pillar of a structure, and which can be stacked and stored. Another object of the present invention is to provide a shaped steel having a cross-sectional shape that is convenient for carrying or cutting by binding or binding.

More specifically, as shown in FIG. 3, the occupied cross-sectional area (W ₁ × W ₂ for angle iron, W ₀ ^{2 for} square tube)
Is almost the same as that of an isosceles tube, and the strength ratio is approximately
It is an object of the present invention to provide a shaped steel which is at least 0.6 and can be produced by hot rolling.

[0016]

The special steel bar of the present invention has a sectional shape as shown in FIG. 1 (a).

The angle (2θ) between the two sides 1 and 1 is 35 ° or more
60 ゜.

Outside the connecting portion (throat) of each side 1, 1, there is a straight portion 2 perpendicular to the two sides of the axis of symmetry (Z).

The ratio (H / H ₁ ) of the height H from the open end of the two sides to the straight line portion and the height H ₁ from the open end to the intersection of the extension lines of the outer straight lines of the two sides is 0.5 to 0.5. 0.9.

Outside the open end of each side 1, 1 is the thickness of the side.
It has a thick bulge 3.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the special steel section of the present invention will be described in more detail.

FIG. 1 (a) is a diagram showing a cross-sectional shape of a Λ-shaped steel. As shown in the drawing, the Λ-section steel has the same shape on both sides with respect to the axis of symmetry Z, and has a straight portion 2 perpendicular to the two axes of symmetry outside the connecting portion of the two sides 1 and 1, It has a bulge 3 outside the open end. The characteristics of this steel bar are as described in (1) above.

The above-mentioned shape is selected because the objective is to obtain a cross-sectional performance equivalent to that of a square tube with substantially the same occupied cross-sectional area as that of the square tube. FIG. 3 (c) described above is a cross-sectional view of an example of the Λ-section steel of the present invention, and the secondary radius of the cross section is substantially circular as indicated by a solid line. Compared to the secondary radius of the cross section of the equilateral angle iron, it can be seen that the difference between the vertical axis and the horizontal axis is small and close to the secondary radius of the square tube. Table 1 shows the cross-sectional performance of this section steel (the dimensions of each section are as shown in Fig. 5 (a) described later).
Is 0.937, which is much larger than the standard angle iron.

The characteristics of the Λ-shaped steel as described above are as described above.
This is caused by the combination of the features described above. The reason for specifying each shape is as follows.

The reason why the angle (2θ) formed by the two sides is 35 to 60 °: the difference in strength between the strong axis and the weak axis is reduced, and the occupied cross-sectional area is close to that of the square tube. In order to make W and H of 1 (a) substantially equal and close to the length of one side of the square tube, 2θ was in the range of 35 to 60 °. The dimensional difference between the width W and the height H is preferably as small as possible in order to reduce the difference in strength between the strong axis and the weak axis and expand the applicable range as a structural material.

Reason for providing the linear portion 2 perpendicular to the two axes of symmetry: This is a means for reducing the strength difference between the strong axis and the weak axis and improving the stackability. The angle between the two sides
When the angle is made as acute as 35 ° to 60 °, it is desirable that the top is not sharp from the viewpoint of production and handling of the product.
The length of the straight portion 2, that is, C in FIG. 1 (a), is considered to be a cross-sectional performance in consideration of the stacking property, and also when it is used in combination with other members as a structural material, as a welding margin. It is good to make it as large as possible without impairing. In addition, the minimum thickness T ₁ of the straight portion is preferably larger than the thickness T of the side 1 in order to secure the strength of the throat.

Reason for setting H / H ₁ to 0.5 to 0.9: In order to use the shaped steel as a structural material such as a column material, the strength difference between the strong axis and the weak axis is reduced as described above. It is desirable that the intensity ratio between the weak axis and the weak axis be as close to 1 as possible. In Λ-shaped steel of the present invention, strength ratio will come determined primarily by two sides forming an angle (2 [Theta]) and H / H ₁ value.
By appropriately selecting the two combinations of the angle 2θ and the height ratio H / H ₁ , it is possible to determine a desired basic cross-sectional shape of the Λ-section steel.

FIG. 4 shows that the height ratio H / H ₁ is 0.5,
Keep 2θ at 35 °, constant at 0.6, 0.7, 0.8 and 0.9
FIG. 6 is a graph showing an example of a calculation result of the strength-to-light ratio (iv / iu) when the angle is changed from to 60 °. As shown in the figure, to obtain the same strength ratio (for example, 0.8), when 2θ is small (close to 35 °), H / H ₁ is also small (close to 0.5), and when 2θ is large ( H when it is close to 60 °)
/ H ₁ must also be large (close to 0.9). However, as shown, when 2θ is 35 ° to 60 °, H / H
_{If 1} is in the range of 0.5 to 0.9, the strength ratio will be about 0.6 or more. In FIG. 4, there is a numerical value in the strength ratio (vertical axis) exceeding 1.0, which means that the strong axis and the weak axis have been switched, and only the previous strong axis becomes the weak axis. ,
After all, the reciprocal of the numerical value becomes the strength ratio in the region exceeding 1.0. For example, the strength ratio of 1.5 on the vertical axis of the figure is 1 / 1.5 = 0.666
・ ・

The reason why the bulges 3 are provided at the open ends of the two sides: the bulges have the role of bringing the position of the center of gravity closer to the center of the cross section and the role of increasing the second moment of area. Further, the bulging portion also contributes to improvement in stackability and weldability as described later. The height A and the thickness D of the bulging portion 3 shown in FIG. 1 (a) are appropriately determined according to the cross-sectional performance required for the type IV steel and to meet additional requirements such as stackability. I just need. Note that, from the viewpoint of ease of rolling, it is preferable that the outer straight portion of the bulging portion 3 is not normal and vertical, but the upper portion is slightly inclined inward (toward the target axis Z).

The type III steel of the present invention is classified into two types according to the inner shape of the throat as shown in FIGS. 1 (b) and 1 (c). Hereinafter, one of the specific methods for determining the dimensions of each part of the type III steel for each type will be described.

(1) In the case of Type I First, 2θ, H and H ₁ are determined from the index as shown in FIG. 4 according to the target strength ratio. Also, the thickness T of the side is determined from the allowable compression force of the Λ-section steel and the like. Then, the total width W and the width C of the throat can be obtained from the following equations (A) and (B), respectively.

W = 2H ₁ tan θ (A) C = W−2H tan θ (B) Throat thickness T ₁ and inner curvature R affect the strength of the throat. In order to secure the strength, it is preferable that T ₁ ≧ T (the thickness of each side). If T ₁ is Kimare inevitably R is also determined.

The height A of the bulging portion 3 is determined in FIG.
It is equal to or smaller than the stacking pitch P of the Λ type steel shown in (b). Since the stacking pitch P is obtained by P = T / sin θ (C), A ≦ P = T / sin θ (D).

The width D of the bulging portion 3 is calculated as follows: D = Atan θ (E)

After the basic sectional shape is determined as described above, the radius (r ₂ , r ₃ , r ₄ , r ₅ ) of each corner is determined.
May be determined as appropriate.

(2) In the case of type II In the same manner as in the case of type I, the angle 2
If θ, the thickness of the throat T ₁ , and r ₃ are determined, FIG.
The dimensions of r ₁ (c), is a _{r 1 ≦ (T-T 1} sin θ) / (1-sin θ) sinθ + r 3 ··· (F). It may be determined r ₁ so as to satisfy the (F) expression. The method of determining the size of the bulge is the same as that of Type I.

FIGS. 5 (a) and 5 (b) show examples of the actual size of the Λ-section steel. (a) is 50 m on one side shown in Table 1
m, the occupied cross-sectional area is almost the same as that of a 2.3 mm square tube,
This is an example of a Type I Λ-shaped steel designed with the goal of obtaining approximately the same cross-sectional performance. Here, H = 50 mm,
The size of each part was determined based on T = 4 mm, 2θ = 50 °, and W = 55 mm. H / H ₁ is about 0.85. (b)
This is an example in which the basic shape is the same as that of FIG. 1A and the strength ratio is designed to be closer to 1.

The cross-sectional performance of the Λ-section steels shown in FIGS. 5A and 5B is shown in Table 1 as C and D. Comparing the performance with that of the equilateral angle steel and the square pipe, it is clear that the Type-II steel has a significantly improved strength ratio compared to the conventional equilateral angle steel, and has a performance close to that of a square pipe. In particular, the strength ratio of the section steel (b) (d in Table 1) is almost 1, and the allowable compressive force is larger than that of the square tube. In addition, all of the materials shown in Table 1 are JIS G3
It is equivalent to 101 SS400.

[0039]

[Table 1]

As described above, it has been described that the Λ-section steel of the present invention has a great advantage in terms of cross-sectional performance as compared with an equilateral angle section steel. On the other hand, when compared with a square tube, in addition to being able to be manufactured only by hot rolling (without steps such as welding), there is an advantage that the stackability is excellent.

FIGS. 6 (a) and 6 (b) are cross-sectional views showing a state where eight square tubes and eight square steels shown in Table 1 and FIG. 3 are stacked.重 ね The stack height (h ₂ ) of the section steel is less than 1/5 of the stack height (h ₁ ) of the square tube. This is described later.
This also contributes to an improvement in the storage efficiency of the nesting rack when the section steel is used as the column material.

When comparing the stacked state of the section steel shown in FIG. 6 (b) with that of the above-described equilateral angle section steel shown in FIG. 2 (b), there is no "lash" when bound and the section steel itself It can be seen that it is superior to equilateral angle iron in storage, transportation, cutting, etc.

FIGS. 6 (c), (d) and (e) show examples of the use of the Λ-shaped steel of the present invention. (c) shows an example of a combination with the channel steel 30, in which the bulging portion 3 is welded to the open end of the channel steel. (d) is an example of a combination of two Λ-shaped steels. In this case, the straight portions 2 may be butted and welded on the side surfaces. Such a composite material can also be used as a structural material of a building. (e) is an example of use as a rail for receiving the wheel 40, and the bulge can be fixed to the floor plate 41 by welding. Also for use in such applications, the stability and running properties of the wheels are superior to that of the equilateral angle iron, which is advantageous.

The Λ-shaped steel of the present invention described so far can be used as a structural material such as columns and beams of various products, and a nested rack is suitable for the use. Hereinafter, a nested rack as an example of use of the section steel of the present invention will be described.

FIG. 7 shows the basic form of the nested rack. A square tube is conventionally used for the pillar material because of its superiority in strength and weight reduction. When a rack using a square tube as a pillar material is nested, it protrudes forward by the size of the square tube as shown in FIG. 6A. As a result, the position of the center of gravity of the rack also moves forward by that amount, and becomes unstable during loading and unloading, and occupies the storage area by that much, which is disadvantageous in terms of space saving. is there.

FIG. 8 is a schematic plan view (extracting only the columns) showing an example of the arrangement of columns when the columns of the rack in FIG. Distance W ₃ of dorsal column 11-1 is narrower than the left and right rail width W _4, also the distance W ₅ of the anterior column 11-2 is wider than the left and right rail width W _4. That is, when a rack of the same shape is inserted in the direction of the arrow, the rack can be nested through the space between the front pillars. Therefore, in the case of nesting, it is possible to perform tight storage with no gap between the rear pillars and between the front pillars as shown in FIG. 6 (b), and as a result, the storage efficiency of the entire rack is improved. become. Note that W ₃ , W ₄ , and W ₅ in FIG. 8 are shown as the distances between the centers of the columns (Λ-shaped steel) for simplicity of explanation, but in actual design, the width of the columns (Λ-shaped steel) itself is used. Needless to say, the design should be made in consideration of the nesting.

The improvement of the storage efficiency as described above leads not only to the rack user, but also to the improvement of the efficiency of product storage and transportation by trucks and the like on the rack manufacturer side. In order to improve such storage efficiency, it is necessary that all of at least four columns are made of Λ-shaped steel. When the equilateral angle iron is used as the column material, the storage efficiency can be expected to be improved.However, since the equilateral angle iron has a major drawback that the strength ratio is small as described above, it is necessary to design the column with the same strength. This increases the width of the columns and increases the weight of the material. That is, equilateral angle irons are unsuitable for column materials. In the case of Λ-shaped steel, the occupied cross-sectional area is almost the same as that of the square tube, and the cross-sectional performance can be made almost the same as that of the square tube.

The Λ-shaped steel of the present invention can be used not only as a column material of a rack but also as a lower rail 12 and an upper rail 16 shown in FIG. Conventionally, these rails were made of equilateral angle iron.

FIG. 9A shows the lower structure (one side front view) of a conventional rack. As shown in this figure, in a conventional rack, the lower rail 12 is attached to a vertical beam 14 on the floor with a connecting member 19. As described earlier with reference to FIG.
Also serves as a spacer for forming a space 20 between the vertical beam 14 and the lower rail 12 for accommodating the forklift claws.
FIG. 9 also shows the upper rail 16 of the lower rack when the racks are stacked. The cross angle theta ₁ of two sides of the angle irons below the rail 12 and slightly smaller than the cross angle theta ₂ of the upper rail 16, it is possible to achieve stable when stacked, still bottom frame of the rack When a load is applied to the rail, it is inevitable that the load moves between the two rails, that is, a one-sided effect occurs. Since the Λ-section steel has a good fitting property, when it is used as a rail material, it plays a role of restraining the upper part of the column, and the load of the bending load on the lower column material at the load point can be reduced.

FIG. 9B is a front view showing the lower structure of the nesting rack in which the upper and lower rails are made of Λ-shaped steel, and FIG. 9C is a side view thereof. In this example, the lower rail 12 is attached to a vertical beam 14 on the floor via a channel 30. This combination has the structure shown in FIG.

The connection between the channel steel 30 and the longitudinal beam 14 may be performed by welding. If the lower rail is provided over the entire length, there is no space between the rack and the floor when the rack is placed on the floor. If the forklift pawl is to be inserted from the side of the rack, cut the lower rail 12 and a part of the channel 30 for attaching the lower rail as shown in FIG. 9 (c). It is sufficient to provide a space therefor.

As can be seen by comparing FIGS. 9A and 9B, the distance from the upper end of the vertical beam 14 to the rack installation surface (floor surface) is shorter in FIG. 9B. Therefore, when racks are stacked in the height direction and when nested, the space in the height direction is saved.

The Λ-shaped steel serving as the lower rail may be attached by using the connecting member 19 shown in FIG. In this case, the effect of saving the space in the height direction is lost, but the effect of stacking stability described below is the same.

As shown in FIG. 9B, when racks are stacked, the lower rail 12 and the upper rail
Since it is exactly the same shape as 14, it fits snugly. Since the intersection (vertex) of the two sides of the Λ-section steel is flat, there is no interference at the vertices as in the case of the equilateral angle steel. Therefore, even if a lateral force acts on the stacked racks,
There is no risk of "displacement" or inclination. In order to use in this way, the height of the bulging portion (A shown in FIG. 1) is determined by the stacking pitch (FIG. 6B) as described above.
It is better to be the same as or smaller than P).

[0055]

As is apparent from the above description, the special steel section of the present invention has a better sectional performance than the conventional equilateral angle steel, and has a good stacking property when a plurality of pieces are stacked. It has a wide range of applications and is excellent in storage and other handling properties. In addition, they can be stacked more compactly than square tubes, and are easy to manufacture.

If this special steel beam is used, for example, as a column material of a nested rack or further as a rail material, a rack having excellent storage properties and high stacking stability can be manufactured as compared with a conventional nested rack. .

[Brief description of the drawings]

FIG. 1 (a) is a diagram showing a basic sectional shape of a special steel bar of the present invention, (b) is one of its throat shapes (type I), and (c) is another one (type II). FIG.

2A is a diagram showing a cross section and a secondary radius of a cross section of a standard equilateral angle iron, and FIG. 2B is a diagram showing a stacked state thereof.

FIG. 3 shows a conventional square tube, an equilateral angle iron and a special steel of the present invention.
It is the figure which showed and compared the cross-sectional shape and sectional secondary radius of the shape steel.

FIG. 4 shows 2θ and H / H in special Λ section steel of the present invention.
₉ is a graph showing an example of the relationship between ₁ and the strength ratio.

FIG. 5 is a design example of a special steel bar of the present invention.

FIGS. 6 (a) and (b) show the stacked state of a square tube and the special square steel of the present invention, respectively, and FIGS. 6 (c) to (e) show examples of use of the special square steel of the present invention. FIG.

FIG. 7 is a perspective view showing a basic shape of a nesting rack.

FIG. 8 is a schematic plan view showing an arrangement state of columns of a nesting rack using the special Λ-shaped steel of the present invention as a column material.

FIG. 9A is a front view of a lower structure of a conventional nesting rack. (b) and (c) are a front view and a side view of a lower structure of a nested rack using the special rectangular steel of the present invention for a rail.

[Explanation of symbols]

1: special steel section, 2: straight section, 3: bulging section, 11-1: rear pillar of nesting rack, 11-2: front pillar, 12: lower rail, 16: upper rail rail

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshio Itoi 14-17, Matsuyama-cho, Nishinomiya-shi, Hyogo (72) Inventor Kenichi Konishi 2-1-1, Osho-nishi-cho, Amagasaki-shi, Hyogo (72) Inventor Fuse Makoto 1-24-24, Kamishinda, Toyonaka City, Osaka Prefecture (56) References Japanese Utility Model Sho 63-8801 (JP, U) Japanese Utility Model Sho 58-20016 (JP, Y2) Japanese Patent Publication 47-47785 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) A47B 47/02 B65D 21/02 B65D 19/08 B21B 1/08 E04C 3/04 F16S 3/00

Claims (1)

(57) [Claims] (1) A cross section perpendicular to the longitudinal direction is a square shaped steel.
The angle between the two sides is 35 ° to 60 °, and the outside of the connecting portion of each side has a straight section perpendicular to the symmetry axis of the two sides, and the height from the open end to the straight section is The ratio of H to the height H ₁ from the open end to the intersection of the extension lines of the two outer straight lines (H / H ₁ )
Is 0.5 to 0.9, and the thickness of the side is outside the open end of each side.
Special rectangular steel with a thicker bulge.