JPH0292401A - Light gage shape steel and its manufacture - Google Patents

Abstract

PURPOSE:To increase strength of a light gage shape steel and to prevent slips between the steels by forming parallel grooves whose direction is orthogonal or slant to the longitudinal direction on both surfaces of a rolled stock for the steel so that the grooves on both the faces are alternately positioned to each other. CONSTITUTION:A strip stock (a) is pinched with rolls 2, 2 and grooves 11 are formed on both surfaces of the stock (a). A light gage shape steel 1 having flanges 1a is formed by working the stock (a). The grooves 11 whose direction is orthogonal or slant to the longitudinal direction of the steel 1 are arranged on both the surfaces of the steel 1. Further, both the grooves 11 on one surface and the grooves 11 on the other surface are formed in parallel and are arranged in mutually alternate patterns. It is useful to form grooves crossing each other. Hence, strength of the steel 1 is increased and slips of the steel 1 on another steel 1 is prevented.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a lightweight steel material and a method for manufacturing the same, and more particularly to a lightweight steel material having grooves on the entire outer and inner surfaces and a method for manufacturing the same. It is related to.

``Prior art'' Light-weight steel materials are steel, galvanized steel sheets, etc., formed by roll forming into cross-sectional shapes such as a hat shape, C shape, groove shape, Z shape, L shape, hanger shape, etc. As a means of increasing the apparent wall thickness and strength, a pair of rolls are used in which ring-shaped protrusions are formed at a constant pitch, perpendicular to the respective rotation axes, in a state of interlocking with each other. means for forming thin parallel grooves along the longitudinal direction on both sides of the strip material by rolling it out and sandwiching it between the pair of rolls, and then roll forming the strip material into the cross-sectional shape as described above. is publicly known.

The lightweight steel material manufactured by this manufacturing method is formed in such a manner that grooves on one surface and grooves on the other surface are alternately located.

"Problems to be Solved by the Invention" First, the grooved lightweight steel materials produced by the conventional method have grooves formed along the longitudinal direction, so compared to those without grooves, , either reinforced in the yam direction or not reinforced in the direction crossing the longitudinal direction.

Second, when forming grooves in the longitudinal direction, the protrusions on the pair of rolls that form the grooves are ring-shaped and perpendicular to the rotation axis, causing slippage between the pair of rolls and the strip material. It's easy,
The grooves formed are shallow and the apparent thickness does not increase much.
Therefore, the degree of increase in strength is also small.

Thirdly, for example, when lightweight steel is used as the base of a partition wall and wall panels are screwed to it with steel screws, or when lightweight steel is used for the edge of a ceiling and ceiling panels are attached to it with steel screws. When attaching screws with manufactured screws, etc., the grooves of conventional lightweight steel materials are formed along the yam direction. If even a slight slip occurs, the wall or ceiling panels will shift, making the joints between the panels larger, for example.

Fourth, if the apparent increase in wall thickness is small, the effectiveness of the screw will also be small, so when a plate is screwed onto lightweight steel,
The fixing strength will be reduced accordingly.

Fifth, when a C-shaped or groove-shaped lightweight steel material is used as a base material with a spacer or the like inserted inside it, there is a problem that the spacer or the like tends to slide in the direction of the potato.

An object of the present invention is to provide a lightweight steel material that solves or improves the above-mentioned problems and a method for manufacturing the same.

"Means for Solving the Problems" In order to achieve the above-mentioned object, one of the lightweight steel materials according to the present invention has grooves on both sides that are perpendicular to the longitudinal direction or inclined at a predetermined angle. Grooves on one side and grooves on the other side are formed in parallel and alternately.

One of the manufacturing methods according to the present invention, in order to manufacture the above-mentioned lightweight steel material, is to unroll the strip material and sandwich it between a pair of rolls each having protrusions at a constant pitch in a state of engagement with the outer periphery of the strip material. A process of forming parallel grooves on both sides in a direction perpendicular to the longitudinal direction of the strip material or a direction inclined at a predetermined angle, and a step of rolling the strip material into a predetermined cross-sectional shape are adopted.

Another lightweight steel material according to the present invention is to form grooves of the first type parallel to each other in a direction perpendicular to the longitudinal direction or in a direction inclined at a predetermined angle on one surface in order to achieve the above-mentioned object. At the same time, a second type of groove that is parallel to each other and intersects this first type of groove at a predetermined angle is formed, and each type of groove is one in which grooves on one side and grooves on the other side are arranged alternately. be.

The second type of groove may be formed along the longitudinal direction of the lightweight steel material, or may be formed not along the longitudinal direction.

In order to manufacture such lightweight steel materials, the present invention proposes two methods.

One method is to unroll the strip material by sandwiching it between a pair of rolls each having protrusions at a constant pitch and meshing with each other on the outer periphery, so that both sides of the strip material are placed in a direction perpendicular to the longitudinal direction of the strip material or at a predetermined angle. forming grooves of the first type in parallel in an inclined direction; and sandwiching the strip material between a pair of rolls having protrusions at a constant pitch so as to engage with the outer periphery of the strip material, and forming grooves of the first kind on both sides of the strip material. This method includes the steps of forming parallel grooves of the second type that intersect with the seed grooves, and roll forming the strip material into a predetermined cross-sectional shape.

The other method is to not unroll the strip material, but to sandwich it between a pair of rolls each having protrusions that mesh with each other on the outer periphery.
forming parallel second type grooves along the longitudinal direction of the strip material on both sides of the strip material, and sandwiching the strip material between a pair of rolls having protrusions at a constant pitch in a state of engagement with the outer periphery of each of the strip materials, The method includes the steps of forming grooves of the first type on both sides of the strip material that intersect the grooves of the second type at a right angle or at a predetermined angle, and a step of roll forming the strip material into a predetermined cross-sectional shape. .

In order to achieve the above-mentioned object, still another light-weight steel material according to the present invention has concave portions and convex portions continuously formed on both sides so as to be repeated alternately, and the back side of the concave portion has convex portions. Furthermore, the rear surfaces of the convex portions are respectively formed in concave portions.

According to the method of the present invention for producing such lightweight steel materials,
While feeding out the strip material, it is sandwiched between a pair of rolls which are alternately embossed with concave portions and convex portions on the outer periphery, thereby forming concave portions and convex portions in a continuous manner on both sides of the strip material; A process of forming this strip material into a predetermined cross-sectional shape is adopted.

Thin iron plates, galvanized steel plates, etc. are used for the strip material.

The width of each groove and the spacing between grooves can be selected as appropriate by considering the specific use, shape, and size of the lightweight steel material, the thickness and material of the strip material used, etc.1 For example, galvanized When using a lightweight steel material made of steel plate as a base material for a partition wall, it is generally preferable to set the inner bottom width of the grooves to 2 to 7 cm, and the center distance between the grooves to about double that. In addition, when using a lightweight steel material made of galvanized steel plate as a base material for a suspended ceiling (field edge support or field edge), the inner bottom width of the groove should be 1 to 4+++a, and the middle and middle distance between the grooves should be It is generally preferable to set it to about double that.

Such groove width and groove spacing can be selected by appropriately setting the size of the protrusions of the pair of rolls used and the spacing between the protrusions.

Furthermore, even in the case where concave and convex portions are alternately and repeatedly formed on both surfaces, the matters described regarding the grooves are generally applicable.

"Function" The lightweight steel material according to the present invention has grooves on both sides in a direction perpendicular to the longitudinal direction or in a predetermined inclined direction, and the grooves are arranged alternately on one side and the other side. , it becomes a small waveform when viewed in cross section. Therefore, the strength increases against forces that cross the longitudinal direction, and when other parts come into contact with the lightweight steel material, it becomes difficult to slip in the longitudinal direction. The screwing strength also increases when attaching.

In addition to the above, in the lightweight type steel material of the present invention having intersecting grooves on both sides, when another member is fixed to the type steel material with a steel screw, the intersecting grooves make it difficult for the tip of the screw to slip.

The same applies to lightweight steel materials in which concave portions and convex portions are alternately and continuously formed on both sides.

One of the methods for manufacturing a lightweight steel material according to the present invention is to sandwich the strip material between a pair of rolls having convex stripes at a constant pitch and engage with each other on the outer periphery thereof, and to apply the strip material on both sides of the strip material at right angles to the longitudinal direction of the strip material. Since grooves are formed in parallel in a direction or in a direction inclined at a predetermined angle and then roll-formed into a predetermined cross-sectional shape, parallel grooves are densely formed on both sides in a direction perpendicular to the longitudinal direction or in a direction inclined at a predetermined angle. A lightweight type steel material having the above-mentioned shape steel material is manufactured, and the grooves on the position surface and the grooves on the other surface of the shape steel material are alternately located, and when viewed in a cross section along the longitudinal direction, the cut end surface has a wavy shape.

In addition, according to another method of manufacturing the lightweight steel material according to the present invention, 9
A lightweight steel material having grooves intersecting on both sides is manufactured, and the first type grooves are parallel to each other, and the second type grooves are parallel to each other.
The grooves on one side and the grooves on the other side are located alternately.

According to another manufacturing method of lightweight steel material according to the present invention,
Concave portions and convex portions are formed alternately and continuously on both surfaces, and the back surfaces of the concave portions and convex portions become convex portions and concave portions, respectively.

“Example” Examples of the manufacturing method and lightweight steel material according to the present invention will be described below with reference to the drawings.

Fig. 1 shows an example of the method for manufacturing lightweight steel materials according to the present invention, in which a strip material a made of a galvanized steel sheet with a wall thickness of 0.5t+* is rolled into a coil at a constant speed by a feed roll (not shown). While rolling it out, sandwich it between the pair of rolls 2.2.

On the outer circumferential surface of the roll 2.2, protrusions 21 and 22 (teeth) parallel to the rotation axis are formed at a constant pitch so as to mesh with each other. Grooves 11 are sequentially formed at regular intervals in parallel to the longitudinal direction on both surfaces of the plate material a, such that grooves 11 are alternately located on the front surface and the back surface.

A strip material a with grooves 11 formed on both sides in this way.

Formed into a predetermined cross-sectional shape using a roll forming device (not shown), an L-shaped inward flange 1a is formed on both sides.
A C-shaped lightweight steel material 1 as shown in FIGS. 2 to 5 was manufactured.

In this example lightweight steel material 1, the distance W between the grooves 11 on both sides (FIGS. 2 and 5) is about 4 mm.

The actual wall thickness t (Fig. 5) is 0.5 mm, but by forming the grooves 11 on both sides, the apparent wall thickness T is approximately 0.8 mm.
5 mm, and when viewed from a surface cut along the longitudinal direction, it has a wavy shape as shown in Figure 5.

In FIG. 3, the force from the direction of arrow A or the mouth is mainly applied to the bottom part 1b, and the force from the direction of arrow C or the mouth is mainly applied to the side wall part IC, but each part has grooves perpendicular to the longitudinal direction. 11 are formed in parallel, the grooves 11 on one side and the grooves 11 on the other side are located alternately, and have a wavy shape in cross section.
It is significantly strengthened against loads from a direction perpendicular to the longitudinal direction.

Figure 4 shows an example in which the lightweight steel material 1 is used as a base material for a partition wall.The lightweight steel material 1 is placed upright at a fixed interval (approximately 50 lsm) at the installation site of the partition wall. Spacers 4 made of metal plates are interposed inside at desired intervals, both ends 41 of each spacer 4 are stretched within seven L-shaped flange la, and wall plates 5 made of plywood are placed on both sides of the shaped steel l. Each wall plate 5 is fixed to the shaped steel material 1 with steel screws 6, and a decorative sheet 7 is applied to the surface.

Since the groove 11 does not extend along the longitudinal direction, both ends 41 of the spacer 4 are caught in the groove 11 within the inward flange, thereby preventing the spacer 4 from sliding.

In addition, the apparent wall thickness T of the lightweight steel material 1 is twice the actual wall thickness t as described above (more than 1.7 times), so when the steel screw 6 is screwed in, the Thickness at which hole 61 (Fig. 5) is formed (effective width of screw 6, apparent wall thickness T)
(equivalent to ) increases, and the screwing strength also improves significantly.

Furthermore, when forming 1lll on the strip material a with the pair of rolls 2 and 2, the protrusions 21 and 22 intersect with the longitudinal direction (that is, the feeding direction of the strip material a). Since there is almost no slippage with the plate material a, when the size of the protrusions is the same, the groove 11 is formed deeper than when n11 is formed in the longitudinal direction on the plate material a.

FIG. 6 shows a strip material a made of a galvanized steel plate with a wall thickness (+,: 15 mm) being fed out as shown in FIG. 1 and sandwiched between a pair of rolls 2.2 to form grooves 11 on both sides. This is an example in which a lightweight steel material 1 is manufactured by roll forming into a C-shaped cross-sectional shape different from that of the previous example, and this steel material 1 is used as a frame for a suspended ceiling.

In the figure, a lightweight steel material l (field edge support) is suspended from the hanger 8 fixed to the tips of a plurality of hanger bolts 81,
Clips 9 are hooked onto this steel frame 1 at predetermined intervals, a lightweight steel frame 1 is hung upward from both ends of the clip 9, and a ceiling plate 51 is attached to the bottom of the steel frame 1 using steel screws. 6, and a decorative board 71 is pasted on the surface of the ceiling board 51.

The apparent wall thickness of the shaped steel material 1 in this example is the groove 11
Due to the formation of , the actual wall thickness increases by about 1.7 times to 0.
It is 61.

In Figure fJ6, the hanging strength of the upper lightweight steel material 1 (field edge support) is increased by the groove 11 in the bottom portion 1b, and the lower l! ! The volume-shaped steel material 11 &) has its side wall portion 1
v in c! The hanging strength is increased by tll.

The other functions of this embodiment are similar to those of the embodiment shown in FIGS. 1-5.

In each of the embodiments described above, the grooves 11 on both sides of the shaped steel material 1 were formed in a direction perpendicular to the longitudinal direction, but instead of this, for example, as shown in FIG. 22
are meshed with each other to form a state (spiral shape) having a predetermined twist angle with respect to the rotation axis, and while feeding out the strip material a at a constant speed, it is sandwiched between the rolls 2, 2, and the material is rolled into the strip material a in the longitudinal direction. On the other hand, it is also possible to form parallel grooves 11 that intersect at a predetermined angle θ and roll form them into a desired cross-sectional shape.

In this example, the intersection angle θ of the grooves with respect to the longitudinal direction
is around 20 degrees, but there is no need to limit it to this;
If the temperature is 5 degrees or more, it can be carried out without significantly reducing the effect.

In the example of FIG. 7, depending on the crossing angle θ, the pair of rolls 2,
There is a case where the strip material a deviates to the side when it is held between the strips 2 and fed out.In such a case, a regulating rail (not shown) is provided to the side in front of the strip material a in the feeding direction to prevent it from deflecting.

FIG. 8 illustrates another method of manufacturing a lightweight steel material according to the present invention, in which a strip material a is fed out at a constant speed, then the strip material a is fed out at a constant speed, and then the strip material a has a predetermined helix angle with respect to the rotation axis and is constant. A first type of parallel groove 11 is formed in a direction intersecting the longitudinal direction at a predetermined intersecting angle θ by sandwiching it between a pair of rolls 2, 2 having protrusions 21 and 22 that engage with each other at a pitch.

Next, the protrusions 31, 32 are twisted in the opposite direction of the protrusions 21, 22 with respect to the rotation axis on the outer periphery, and are sandwiched between a pair of rolls 3, 3 formed with a constant pitch of protrusions 31, 32 that engage with each other, and are rolled at a predetermined length in the longitudinal direction. Directions that intersect at an intersection angle θ°,
Also, a second type of groove 12 is formed which intersects with the first type of ill.

Further, this is sequentially formed into a lightweight steel material 1 having a C-shaped cross section and having an inward flange 1a curved in an L-shape on the r4 side edge, as shown in FIGS. 11 and 12, using a roll forming device (not shown). .

According to this manufacturing method, the first type groove 11 and the second type groove I
2, the latter is formed slightly deeper.

Furthermore, when the first type of grooves 11 are formed, the apparent thickness of the strip material a increases, so the rolls 2, 2 for forming the first type of grooves 11 are placed close to each other as shown in FIG. It is preferable that the rolls 3, 3 forming the second type of grooves 12 be set slightly apart as shown in FIG. 10, and that the heights of the protrusions 31 and 32 are also set slightly large.

In the manufacturing method of this embodiment, the crossing angle θ is 4
It is preferable that the intersection angle θ° is 5 degrees or more and 135 degrees or less.

In the lightweight steel material 1 of this embodiment, the grooves 11 and 12 are formed on both sides or alternately. It exhibits a waveform as shown in Fig. 13. Therefore, the intersecting grooves 11 and 12 significantly strengthen the structure against loads from the directions of arrows A and C and C and C in FIG. 12.

Moreover, the lightweight steel material l of this example has a substantial wall thickness t of O,
S■, the apparent thickness T is 0.85+*m, and the groove 11
The inner bottom widths of grooves 11 and 12 are approximately 1.5 mm, and the center distances between grooves 11 and 12 are 4 cm.

Furthermore, since the lightweight steel material 1 of this embodiment has densely formed intersecting grooves on both sides, when the steel screw 6 is screwed in as shown in FIG. 4 or FIG. 6, the tip of the screw 6 does not easily slip. .

The other functions are the same as those of the embodiments shown in FIGS. 1 to 5, and therefore their explanation will be omitted.

In the embodiment shown in FIG. 8, the first type of grooves 11 can be formed perpendicularly to the longitudinal direction of the strip material a, similar to the grooves 11 in FIG. Since the second type groove 12 only needs to intersect with the first type groove 11,
If the first type groove 11 is refined so as to cross the longitudinal direction as shown in FIG. 8, the second type groove 12 is formed perpendicular to the longitudinal direction as shown in FIG. It can also be implemented even if the second type groove 12 is formed along the longitudinal direction of the strip material a.

FIG. 14 shows yet another embodiment of the method of the present invention, in which a strip material a made of galvanized steel sheet is fed out at a constant speed.

A pair of rolls 3.3 are provided at the front in the feeding direction to sandwich the strip material a, and each of the rolls 3.3 has a flange-shaped protrusion 31, 33 perpendicular to the rotational axis on the circumferential surface. Since they are formed at a constant pitch in an interlocking state, parallel second type grooves 12 are formed along the longitudinal direction on both sides of the strip material a that is fed out between the rolls 3.3.

Furthermore, a pair of rolls 2.2 are provided in front of the rolls 2.2, which are parallel to the rotation axis and have protrusions 21.22 formed at a constant pitch on the outer periphery to engage with each other. A first type groove 11 is sandwiched between the rolls 2.2 and intersects the second type groove 12 at right angles on both sides of the strip material a.
form.

Next, this strip material a is sequentially formed into a predetermined cross-sectional shape using a roll-forming machine (not shown) to produce a lightweight steel material 1 having grooves 11 and 12 intersecting in a lattice pattern on both sides.

The lightweight steel material l manufactured by the method of this example is [1
1 increases the strength against loads in the direction perpendicular to the longitudinal direction.

The other functions are the same as those of the embodiment shown in FIG. 8, so their explanation will be omitted.

In the embodiment shown in FIG. 14, the ridges 21 of the rolls 2,
．． 22 may be formed in a twisted state with respect to the rotation axis, and the first type groove 11 may be formed so as to intersect with the longitudinal direction of the strip material a at an angle other than a right angle.

1511Z to 17, another example of a lightweight steel material according to the present invention and its manufacturing method will be described. 2. While paying out the strip material a in the same manner as in the previous example, as shown in FIG. 17, , a concave portion 24 (25) and a convex portion 23 on the outer periphery, respectively.
(25) are sandwiched between a pair of rolls which are alternately embossed, and as shown in FIGS. 15 and 16, concave portions 14 and convex portions 13 are alternately and continuously formed on both sides of the strip material a,
This strip material a is formed into a predetermined cross-sectional shape in the same manner as in each of the above embodiments.

The recesses 14 and the protrusions 13 appear continuously and alternately on both sides of the lightweight steel material manufactured in this way, and the recesses 14 on one surface become the protrusions 13 on the other surface. .

The concave portion 14 and the convex portion 13 may have any shape.

This lightweight steel material has an increased apparent thickness due to the alternating concave and convex portions 14°13, which increases its strength against loads from any direction, increases the screwing strength of screws, etc., and improves the screw tip. Prevents slipping when in contact.

"Effects of the Invention" The manufacturing method according to the present invention and the lightweight steel material produced therefrom have parallel grooves on both sides that are perpendicular to the longitudinal direction or intersect at another predetermined angle, and the grooves are in one side. Since the grooves and the grooves on the other surface are arranged alternately, the strength against loads in the direction perpendicular to the shaped steel increases significantly, and also prevents sliding in the longitudinal direction of other members that come into contact with the shaped steel. be able to.

Since this groove can have a greater depth than when grooves are formed parallel to the longitudinal direction, the apparent wall thickness can be further increased, and the strength can be increased as described above. It is also possible to increase the screwing strength when other members are screwed.

In addition, by forming another groove parallel to the groove that intersects with the groove, sliding with other members can be restricted in any direction, and when other members are screwed with steel screws or the like, Since the tips of the screws do not slip, the gaps between the members fixed to the shaped steel do not become large and the screws can be screwed together more firmly than in one piece.

Furthermore, a lightweight steel material in which concave portions and convex portions are alternately and consecutively formed on both sides has substantially the same effect as described above.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted perspective view showing an example of the manufacturing method according to the method of the present invention, FIG. 2 is a partial plan view of a lightweight steel material manufactured by the manufacturing method of FIG. 1, and FIG. 3 is a side view thereof. Fig. 4 is a partial plan sectional view showing an example of using this lightweight steel material as a base material for a partition wall, Fig. 5 is a partially enlarged cut end view of the lightweight steel material, and Fig. 6 is a cut end view of the lightweight steel material. FIG. 7 is a partial perspective view for explaining another example of the manufacturing method; FIG. 8 is a partial cross-sectional view of another example of lightweight steel material used as a base material for a ceiling; FIG. 8 is another manufacturing method according to the present invention. FIG. 9 is a partially enlarged sectional view of a roll for forming the first type of groove in the strip material in FIG. 8, and FIG. 1O is a partial perspective view showing an embodiment of the method. 11 is a partially enlarged end view of the roll forming the grooves, FIG. 11 is a partial front view of the lightweight steel material manufactured by the manufacturing method explained in FIG. 8, FIG. FIG. 14 is a partial perspective view showing still another example of the manufacturing method according to the present invention,
Figures 15 and below show still other examples; Figure 15 is a partial plan view of a strip material with unevenness processed before forming;
FIG. 16 is a partial cross-sectional view taken along arrow B-B in FIG. 15.
Figure 1'517 is a partial sectional view of a state in which unevenness is being processed into a strip material using a pair of rolls. Explanation of main symbols in the figure: a: strip material, l: lightweight steel material, 11.12: groove, 13
14 is a convex part, 14 is a concave part, 1a is an inward flange, lb is the bottom of the lightweight steel material, lc is the side wall of the lightweight steel material, 2.2 is a pair of rolls, 21.22 is a convex strip, 23.26 is a convex part Part, 2
4.25 is a concave portion, 3, 3 is a pair of rolls, 31.32 is a protrusion (Figure 1, Figure 10, Figure 11, Figure 5, Figure 9, Figure 12)

Claims (1)

[Scope of Claims] (1) Grooves are formed on both sides in a direction perpendicular to the longitudinal direction or inclined at a predetermined angle in parallel with grooves on one side and grooves on the other side being alternately located. A lightweight steel material characterized by having: (2) Both sides have grooves of the first type parallel to each other in a direction perpendicular to the longitudinal direction or in a direction inclined at a predetermined angle, and grooves of the first type parallel to each other that intersect with the grooves of the first type at a predetermined angle. A lightweight steel material having a second type of groove, and the various types of grooves are characterized in that grooves on one side and grooves on the other side are positioned alternately. (3) The lightweight steel material according to claim 2, wherein the second type groove is formed along the longitudinal direction. (4) The lightweight steel material according to claim 2, wherein the second type groove is formed not along the longitudinal direction. (5) A lightweight steel material in which concave portions and convex portions are alternately and continuously formed on both sides, and the convex portion is formed on the back side of the concave portion, and the concave portion is formed on the reverse side of the convex portion. (6) While the strip material is being fed out, it is sandwiched between a pair of rolls having convex stripes at a constant pitch that are engaged with each other on the outer periphery, so that both sides of the strip material are perpendicular to the longitudinal direction of the strip material or inclined at a predetermined angle. 1. A method for manufacturing a lightweight steel material, the method comprising the steps of: forming grooves parallel to each other in the direction of the steel strip; and roll-forming the strip material into a predetermined cross-sectional shape. (7) While the strip material is being fed out, the strip material is sandwiched between a pair of rolls having convex stripes at a constant pitch that are engaged with each other on the outer periphery, so that both sides of the strip material are perpendicular to the longitudinal direction of the strip material or inclined at a predetermined angle. forming grooves of the first type parallel to each other in the direction of the strip material, and sandwiching the strip material between a pair of rolls having protrusions at a constant pitch so as to mesh with the outer periphery of the strip material, and forming grooves of the first type on both sides of the strip material. 1. A method for producing a lightweight steel material, comprising the steps of: forming parallel grooves of the second type that intersect with the grooves of the strip material; and roll-forming the strip material into a predetermined cross-sectional shape. (8) While the strip material is being fed out, it is sandwiched between a pair of rolls having protrusions that are meshed with each other on the outer periphery to form parallel second type grooves along the longitudinal direction of the strip material on both sides of the strip material. and sandwiching the strip material between a pair of rolls having protrusions at a constant pitch in a state of engagement with each other on the outer periphery,
The method includes the steps of forming a first type groove on both sides of the strip material that intersects the second type groove at a right angle or at a predetermined angle, and a step of roll forming the strip material into a predetermined cross-sectional shape. A method for producing lightweight steel material, characterized by: (9) Step of forming concave portions and convex portions on both sides of the strip material so that they are alternately continuous, by sandwiching the strip material between a pair of rolls that have alternately embossed concave portions and convex portions on the outer periphery while feeding the strip material. A method for manufacturing lightweight steel material, comprising the steps of: and forming the strip material into a predetermined cross-sectional shape.