JPH0929376A - Manufacture of structural member for ditch lid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a steel strip for a ditch lid to be formed into irregularities to prevent slipping on its upper surface using a roll capable of easy manufacturing. SOLUTION: A tapered groove of the prescribed width which is gradually deeper toward one end is formed in a pair of rolls to hold the steel strip, the steel strip is passed to be expanded out of the deeper groove side by the prescribed amount, and formed to be gradually thicker toward one side end, and a projecting bar is formed on the wide end face. The steel strip is pressed in the width direction using a roll 19 on which the groove 18 is formed in a zigzag manner on a higher part 17 to form a projected part 20 in a zigzag manner on the top surface of the projection 22. Deformation by the buckling is corrected by passing the strip into a roll 19, and the projected side is pressed to make it flat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structural material for forming a groove lid, and more particularly to a method for manufacturing a structural material for a groove lid having a rectangular or I-shaped cross section with an uneven upper surface to prevent slippage.

[0002]

2. Description of the Related Art Generally, a gutter cover attached to a drainage gutter such as a side gutter of a road is formed in a rectangular outer frame structure member by welding both ends to opposite long sides of the outer frame structure member. It is composed of short structural materials that are installed in parallel and twist bars that are welded to each short structural material in parallel with the short structural materials in a direction orthogonal to each other. There is also one in which convex portions are formed at a constant pitch for prevention.

Conventionally, a short structural material having a convex portion has been manufactured by a method of hot-rolling by pressing with a roll having a concave portion corresponding to the convex portion on the side end surface of the strip steel on the peripheral surface. The height of the convex portion is difficult to obtain, and when the printing pressure is increased to obtain the convex portion of sufficient height, the strip steel buckles and deforms, and dimensional accuracy cannot be obtained. Japanese Patent Fair 3-4
No. 4841 discloses a roll provided with a circumferential groove having a sectional ridge for holding a strip steel having a circumferential groove for forming a ridge formed on the groove bottom, and a circumferential strip for holding the strip at a position corresponding to the circumferential groove. Using a roll having a groove, a first step of passing a strip steel through the circumferential grooves of both rolls and printing in the strip steel width direction to form a ridge along the longitudinal direction at one end of the strip steel, A roll having a narrow convex portion and a wide convex portion in the circumferential direction is used, and a strip plate is passed between both rolls to narrow the central portion of the strip plate with the wide convex portion to form an I-shaped cross section and The second step of narrowing the ridges by narrowing the ridges with a narrow convex portion and the roll having a peripheral edge with an uneven groove bottom are used, and the I-shaped steel subjected to the second step is passed between both rolls. It consists of the third step of forming unevenness on the top surface of the ridge, forming a thin ridge to make it susceptible to printing pressure deformation, thereby forming a convex portion of sufficient height. The method of the trench cover structural member which is adapted to achieve greater slip prevention effect has been proposed.

[0004]

Another method of enhancing the slip preventing action is to form a wide side end surface of the groove cover structural member formed in an uneven shape, and if the side end surface becomes wider, Wider tire contact surface reduces tire wear and facilitates walking with high heels. A first object of the present invention is to provide a method of manufacturing a structural member for a groove lid, in which a wide side end surface having irregularities can be easily formed, and a second object is to provide a ridge. An object of the present invention is to provide a method of manufacturing a groove lid structural material that can be easily formed. Further, a third object is that the unevenness is formed by a roll which can be easily manufactured.

[0005]

According to a manufacturing method for achieving the first object, one of a pair of rolls for narrowing the strip steel in the thickness direction, preferably a constant width in the opposite direction, preferably the same width as the strip steel. A groove having a groove width wider than that of the strip steel is formed in the circumferential direction so that the groove bottom gradually becomes deeper toward one end. And a second step of forming unevenness by pressing the side end surface of the strip steel having a wide width with the roll having unevenness formed in the circumferential direction in the width direction of the strip steel to form unevenness. It is characterized in that

A manufacturing method for achieving the second object is as follows:
Form a groove with a constant width in the opposite direction of the pair of rolls that press the strip steel in the thickness direction at a constant interval, preferably a narrower width by a protrusion than the strip steel in the circumferential direction. The strip steel is passed through so that one end of the strip steel protrudes from the groove, and the first step of forming the strip steel side end protruding from the groove into a ridge by the groove edge, and unevenness in the circumferential direction are formed. It is characterized in that it comprises a second step of forming unevenness by printing the top surface of the ridge in the width direction with a roll. Another manufacturing method for achieving the second object is to form a stepped peripheral groove composed of a wide groove and a narrow shallow groove on the opposite side of a pair of rolls for narrowing the strip steel in the thickness direction,
A first step in which a strip steel is fitted into a circumferential groove between both rolls to form a strip steel side end portion into a ridge, and a ridge top surface is formed with a roll having irregularities formed in the circumferential direction. It is characterized by comprising a second step of forming an unevenness by printing pressure in the width direction of steel. Second
Yet another manufacturing method to achieve the purpose of, among the pair of rolls for narrowing the strip steel in the thickness direction, one roll has a wide groove, and the other roll has the same groove width as the groove, A stepped groove consisting of a stepped narrow shallow groove is formed at one end in the circumferential direction, and the strip steel is fitted into the groove between both rolls and passed through to project the end of the strip steel side. It is characterized in that it comprises a first step of forming a ridge and a second step of forming ridges and valleys by pressing the top surface of the ridge in the width direction of the strip steel with a roll having ridges and valleys in the circumferential direction.

In each of the above methods, it is preferable that the wide groove formed in the roll is also formed so that the groove bottom gradually becomes deeper toward the side where the ridge is formed. The ridges are easily formed because the ridges are pushed toward the side where the ridges are formed. Of the roll grooves used in each of the above methods,
In the case where the groove bottom is formed to be gradually deeper, one end on the deepened side naturally forms a step, but the other end may or may not be stepped. If the other end is stepped, this enables the strip steel to be positioned, and if the groove width is the same width as the strip steel and the strip steel fits, the strip steel will be at both ends of the groove. It is positioned and does not shift in the width direction. Therefore, the strip steel is formed in a shape along the cross-sectional shape of the groove.

A manufacturing method for achieving the third object is as follows.
It is characterized in that a roll having a constant width is formed in the circumferential direction on the roll for forming the unevenness used in each of the above-mentioned manufacturing methods, and the unevenness is formed on the top surface of the high part. Another manufacturing method for achieving the third object is to form a convex portion having a width narrower than that of the strip steel on the opposite side of a pair of rolls for narrowing the strip steel so that the strip steel protrudes from the convex portion. The first step to form an I-shaped section by passing it between the two rolls and a high part with a constant width in the circumferential direction,
It is characterized by comprising a second step of forming pressure on the side end surface of the steel material formed into an I-shaped cross section with a roll having unevenness formed on the high portion in the width direction to form the unevenness on the side end surface. Still another manufacturing method for achieving the third object is to form a wide shallow groove and a narrow deep groove at both ends of the shallow groove in the circumferential direction on the opposite sides of a pair of rolls for narrowing the strip steel in the thickness direction. The first step of forming the strip steel into the groove of both rolls to form an I-shaped cross section, and forming a high portion with a constant width in the circumferential direction and forming an unevenness on the high portion to form an I-shaped section It is characterized in that it comprises a second step of applying pressure to the side end surface of the steel material in the width direction to form irregularities on the side end surface. Still another manufacturing method for achieving the third object is one of a pair of rolls for narrowing the strip steel in the thickness direction, in which one roll has a wide shallow groove and narrow deep grooves at both ends of the shallow groove. While forming in the circumferential direction, a groove is formed in the circumferential direction on the other roll at a location corresponding to the deep groove, or a location corresponding to the shallow groove is formed as a high portion, and the strip steel is passed between both rolls. The first step of forming an I-shaped cross section, a high portion having a constant width is formed in the circumferential direction, and the side end surface of the steel material formed in the I-shaped section is pressed in the width direction by a roll having irregularities formed on the height.
It is characterized by comprising a second step of forming irregularities on the side end surface. Yet another manufacturing method for achieving the third object is a first convex portion having a width narrower than that of the strip sheet steel, and a second convex portion having a constant gap between the pair of rolls for narrowing the strip sheet steel. Is formed in the circumferential direction, the strip steel is passed between both rolls so as to protrude from the first convex portion and the second convex portion, and the first convex portion forms an I-shaped section, The first step of forming the strip steel side end portion into a ridge by the second convex portion, and a roll having a high width of a certain width formed in the circumferential direction and unevenness on the peripheral surface of the high height to form an I-shaped cross section It is characterized in that it comprises a second step of applying pressure to the end face of the formed steel material in the width direction to form irregularities on the end face. Yet another manufacturing method for achieving the third object is
A wide shallow groove is formed on each side of a pair of rolls that narrow the strip steel in the thickness direction, a narrow deep groove is formed at both ends of the shallow groove, and a shallow groove adjacent to one deep groove is formed in the circumferential direction. The strip steel was passed through the groove of the roll to form an I-shaped cross section, and the first step of forming one side end into a ridge, and a high portion with a constant width was formed in the circumferential direction, and irregularities were formed in the high portion. It is characterized in that it comprises a second step of forming pressure on the side end surface of the steel material formed into a I-shaped section by a roll in the width direction to form irregularities on the side end surface. Another alternative manufacturing method for achieving the third object is one of a pair of rolls for narrowing the strip steel in the thickness direction, in which one roll has a wide shallow groove and both ends of the shallow groove have a narrow shallow groove. A deep groove and a narrow shallow groove adjacent to one of the deep grooves are formed in the circumferential direction, and a groove is formed in the other roll at a location corresponding to the deep groove in the circumferential direction, or corresponding to the shallow groove. The first step of forming a portion as a high portion and passing the strip steel between both rolls to form an I-shaped cross section, and a roll having a high width of a certain width formed in the circumferential direction and unevenness on the high portion It is characterized by comprising a second step in which the side end face of the steel material formed into a shape is pressed in the width direction to form irregularities on the side end face. It is difficult to form unevenness on the groove bottom by machining, and since it has to be performed by electric discharge machining, the cost becomes high, and it is not easy to visually check the machining degree. It is easy to form irregularities on the top surface of the high part by machining, like the roll used in 1., and it is easy to visually confirm the processing steps.

[0009]

1 to 3 show an example of the method of the present invention. In the first step shown in FIG. 1, a pair of rolls 1 and 2 arranged side by side at regular intervals are arranged respectively. A groove 3 having the same diameter as that of the roll is gradually deepened from one end to the other end to form a tapered groove 3 having a constant width in the circumferential direction, and a strip steel 4 having the same width as the groove width is passed between both rolls. Printing is performed in the thickness direction and extruded toward one end to gradually increase the wall thickness.

In the second step shown in FIG. 2, one of the pair of rolls 6 and 7 for impressing the strip steel 4 which has undergone the first step in the width direction has a thin portion on one side of the strip steel on one roll 6. A circumferential groove 8 to be fitted is formed, and a high portion 9 having a constant width is circumferentially formed on the other roll 7 having a constant distance from the roll 6,
The inclined groove 11 is formed on the top surface of the convex portion at regular intervals in the circumferential direction to form a helical gear shape, and the strip steel 4 having the wide end surface facing upward is passed between the rolls to form a wide end surface. As shown in FIG. 5, the inclined convex portion 12 is formed.

In the third step shown in FIG. 3, rolls 14 and 15 in which a notch 13 is formed on the other end of the groove of the roll shown in FIG. The pressure is applied through the steel in the thickness direction to correct the deformation due to buckling, and the function to level the bulged portion due to the formation of irregularities is performed. 5 to 7 show another example of the method of the present invention. In the first step shown in FIG. 5, the rolls 1 and 2 shown in FIG.
Is used to press the strip steel 4 in the same manner as described above, and the thickness of the extruded wall is gradually increased toward one end.

In the second step shown in FIG. 6, of the rolls 6 and 7 shown in FIG.
A roll 19 having grooves 18 formed in a zigzag shape is used to press the strip steel 4 in the width direction to form a convex portion 20 in a zigzag shape on the wide end surface as shown in FIG. In the third step shown in FIG. 7, the rolls 1 and 2 shown in FIG. 5 are used again to correct the deformation due to buckling and to make the lateral bulge formed by the recess due to the printing pressure uniform.

9 to 11 show still another example of the method of the present invention. In the first step shown in FIG. 9, the rolls 1 and 2 shown in FIG. The groove 3 is passed through so as to protrude from the deep groove side by a certain amount, the wall thickness is gradually increased toward one end, and the ridge 22 is formed on the wide end surface. In the second step shown in FIG. 10, the rolls 6 and 19 shown in FIG. 6 are used to form the protrusions 23 in a zigzag shape on the top surface of the ridge, as shown in FIG.

In the third step shown in FIG. 11, the rolls 1 and 2 are used to pass the protrusions 25 so as to protrude from the grooves 3 to correct the buckling of the strip steel and to press the side surfaces of the ridges. It acts like a flat surface. In each of the above-mentioned manufacturing methods, the rolls used in the first and third steps may be such that the groove 3 is deepened, or the groove 3 is deepened and a narrow shallow groove in which the protrusion 22 is housed is stepped, One of them may be a driving roll and the other may be a driven roll that is driven by the roll, and as described later, only one roll may be formed with a groove deeply or deeply with a groove. A narrow groove for accommodating 22 may be formed to form a step. 13 to 15 show still another example of the method of the present invention. In the first step shown in FIG. 13, one roll 2 of the pair of rolls 25 and 26 as shown in FIG.
5, a flat groove 27 having the same width as that of the strip steel 4 is formed, and peripheral grooves 28 are formed at both ends of the flat groove 27.
6, a pair of peripheral grooves 29 are formed at positions corresponding to the peripheral grooves 28, and the strip steel 4 is fitted in the flat grooves 27 and is pressed in the thickness direction to form an I-shaped cross section. In the second step shown in FIG. 14, a circumferential groove 31 into which the thick portion of the I-shaped steel end fits is formed in the roll 30, and the roll 7 shown in FIG.
Similar to the above, the inclined groove 1 is formed in the high portion 9 having a constant width at regular intervals in the circumferential direction.
1 is formed into a helical gear shape, and the rolls 30 and 32 are passed through the strip steel 33 having the I-shaped cross-section after the first step to form the inclined convex portion 34 on the side end face as shown in FIG. . In the third step shown in FIG. 15, the rolls 25, 2 shown in FIG.
Using the same roll as that of No. 6, the pressure is applied in the thickness direction through the strip steel 33 having the I-shaped cross-section after the second step, and the action of correcting the deformation due to buckling and the strip having the I-shaped cross-section that is swollen by the formation of the unevenness Performs the action of reducing the thickness of the steel edge. In the above-mentioned manufacturing method, as the rolls used in the first and third steps, a roll having a high portion having a width narrower than that of the strip steel is used instead of the roll having the groove, and both side portions of the strip steel are high portions. By passing the rolls so that they protrude further, the cross section I
It may be formed into a strip-shaped steel strip, or a strip-shaped steel strip with an I-shaped cross section may be passed between rolls to correct the deformation and swell. Moreover, as a roll used in the first and third steps,
It is also possible to use the same groove on both sides of the roll, that is, a wide shallow groove and narrow deep grooves formed at both ends in the circumferential direction. In another method, instead of the roll 32 shown in FIG. 14, the roll 19 shown in FIG. 6 is used, and a convex portion is formed in a zigzag shape on the end face of the thick portion of the I-shaped steel end portion. 18 to 2
Reference numeral 0 indicates another example of the method of the present invention. In the first step shown in FIG. 18, one of the pair of rolls 39, 40 arranged side by side as shown in FIG. Steel 4
A flat groove 41 having the same width as that of the flat groove 41 is formed, and a peripheral groove 42 is formed at one end and the other end of the bottom portion of the flat groove 41, and a pair of peripheral grooves 43 is formed on the other roll 40 at a position corresponding to the peripheral groove 42. The strip steel 4 is inserted between the rolls so as to fit into the flat groove 41, the strip steel 4 is pressed in the thickness direction to form an I-shaped cross section, and a ridge is formed on one end. 44 is formed. FIG.
In the second step shown in FIG. 5, the roll 45 is formed with the circumferential groove 46 into which the thick portion of the steel strip end having the I-shaped cross section is fitted, and the roll 47 is provided with the roll having the same structure as the roll 19 shown in FIG. 22. As shown in FIG. 22, an inclined convex portion 49 is formed on one end face of each of the rolls 45 and 47 by passing the strip steel 48 having the I-shaped cross section after the first step. In the third step shown in FIG. 20,
By using a roll having the same structure as the rolls 39 and 40 shown in FIG. 18, pressure is applied in the thickness direction through the strip steel having the I-shaped cross-section after the second step, and the action of forcing the deformation due to buckling and the formation of unevenness It acts to reduce the wall thickness of the bulged I-shaped steel end. Also in the above manufacturing method, the roll used in the first and third steps is formed into an I-shape by using a roll having a wide high portion and a narrow high portion for impressing the ridge, and the ridge is formed. Can be formed, and the bulge of deformation can be adjusted. It is also possible to use rolls having the same structure in which the same circumferential groove is formed on both sides of the roll.

[0015]

The present invention is configured as described above and has the following effects. According to the manufacturing method of claim 1,
It is possible to form a wide side end surface where unevenness is formed in one step only by pressing the strip steel in the thickness direction, so that the slip prevention effect and the tire wear prevention effect can be enhanced, and in high heels Make walking easier.

According to the manufacturing method of the second to fourth aspects, it is possible to surely form the ridge having a required height in one step. In the manufacturing method according to the fifth aspect, at the time of printing pressure in the thickness direction, the strip steel tends to be extruded to the side where the ridge is formed, so that the ridge is easily formed. If the both ends of the groove formed in the roll are formed in a step shape as in the manufacturing method according to claim 6, the strip steel is positioned by the step, and it is possible to prevent or reduce the deviation in the width direction. .

By using a roll as in the manufacturing method according to any one of claims 7 to 13, irregularities on the roll can be easily machined and the degree of processing can be visually confirmed. , 12 and 13 can be used as a driving roll and the other can be a driven roll driven by the roll, and only one roll can be driven. .

[Brief description of drawings]

FIG. 1 is a perspective view showing a first step of the first embodiment.

FIG. 2 is a perspective view of the second step.

FIG. 3 is a perspective view of the same third step.

FIG. 4 is a perspective view of the groove cover structural material obtained in the first embodiment.

FIG. 5 is a perspective view showing a first step of the second embodiment.

FIG. 6 is a perspective view of the second step.

FIG. 7 is a perspective view of the third step.

FIG. 8 is a perspective view of the groove lid structural member obtained in the second embodiment.

FIG. 9 is a perspective view showing a first step of the third embodiment.

FIG. 10 is a perspective view of the second step.

FIG. 11 is a perspective view of the same third step.

FIG. 12 is a perspective view of a groove lid structural member obtained in a third embodiment.

FIG. 13 is a perspective view showing a first step of the fourth embodiment.

FIG. 14 is a perspective view of the second step.

FIG. 15 is a perspective view of the same third step.

FIG. 16 is a sectional view of a main part of a roll.

FIG. 17 is a perspective view of a groove lid structural member obtained in a fourth embodiment.

FIG. 18 is a perspective view showing a first step of the fifth embodiment.

FIG. 19 is a perspective view of the second step.

FIG. 20 is a perspective view of the same third step.

FIG. 21 is a sectional view of a main part of a roll.

FIG. 22 is a perspective view of the groove lid structural member obtained in the fifth embodiment.

[Explanation of symbols]

1, 2, 6, 7, 14, 15, 19, 25, 26, 3
0, 32, 39, 40, 45, 47 ... Roll 3, 18 ... Groove 4, 33,
48 ... Strip steel 8, 28, 29, 31, 42, 43, 46 ... Circumferential groove 12, 20, 34, 49 ... Convex part 11 ... Inclined groove 9, 17 ... High part 22, 44
..Slits 27 and 41 ... Flat groove

Claims (13)

[Claims] 1. A groove having a constant width in which the groove bottom gradually becomes deeper toward one end is circumferentially formed in at least one of a pair of rolls pressing a strip steel in the thickness direction, and the roll is fitted into the groove. The first step is to gradually increase the thickness of the strip steel that has been passed between the two rolls toward one end, and the side end surface of the strip steel that is formed to be wide with the roll having irregularities formed in the circumferential direction. And a second step of forming unevenness by applying a pressure to the groove. 2. A wide groove is formed on the opposite side of a pair of rolls for narrowing the strip steel in a thickness direction at regular intervals, and the strip steel is placed between both rolls at one end of the strip steel. The first step of passing through the groove so as to protrude from the groove, and forming the strip steel side end protruding from the groove into a ridge by the groove edge, and the ridge top surface with a roll having unevenness in the circumferential direction. A method of manufacturing a groove cover structural material, comprising a second step of forming pressures in the width direction to form irregularities. 3. A strip-shaped circumferential groove consisting of a wide groove and a narrow shallow groove is formed on the opposite side of a pair of rolls for narrowing the strip steel in the thickness direction, and the strip steel is surrounded between both rolls. The first step of fitting the groove into the groove and forming the strip steel side end into a ridge, and pressing the top of the ridge in the width direction of the strip steel with a roll having irregularities in the circumferential direction, And a second step of forming a groove cover structure material. 4. A pair of rolls for narrowing the strip steel in the thickness direction, one roll having a wide groove, the other roll having the same groove width as the above groove, and a step at one end thereof. A first step in which stepwise grooves each having a narrow shallow groove are formed in the circumferential direction, and a strip steel is fitted between the rolls and passed through the groove to form a ridge on the end face on the strip steel side. A method for producing a groove lid structural material, which comprises a second step of forming the unevenness by printing the top surface of the ridge in the width direction of the strip steel with a roll having unevenness formed in the circumferential direction. 5. The groove lid according to any one of claims 2 to 4, wherein the groove bottom of the wide groove formed on the roll is formed so as to gradually become deeper toward the side where the ridge is formed. For manufacturing structural materials for automobiles. 6. The method for producing a groove lid structural material according to claim 1, wherein the groove formed in the roll has a step at both ends. 7. A roll for forming a concavo-convex roll is provided with a high part having a constant width in the circumferential direction, and a roll having a concavo-convex pattern on the top surface of the high part is used. A method of manufacturing the groove cover structural material according to claim 1. 8. A pair of rolls for narrowing the strip steel in the thickness direction is provided with a convex portion having a width narrower than that of the strip steel, and the strip steel is passed between the rolls so as to protrude from the convex portion. The first step of forming an I-shaped cross section, and forming a high portion of constant width in the circumferential direction,
A groove cover structural material comprising a second step of forming pressure on the side end surface of a steel material formed in an I-shaped cross section with a roll having unevenness formed on a high portion to form the unevenness on the side end surface. Production method. 9. A shallow groove having a wide width and narrow deep grooves at both ends of the shallow groove are circumferentially formed on opposite sides of a pair of rolls for narrowing the strip steel in the thickness direction, and the strips are formed in the grooves of both rolls. First step of forming the steel into an I-shaped section through the steel, and forming a high portion with a constant width in the circumferential direction, and pressing the side end surface of the steel material formed in the I-shaped section in the width direction with a roll having irregularities formed on the high portion. A method for manufacturing a groove cover structural material, comprising a second step of forming irregularities on the side end surface. 10. A pair of rolls for narrowing the strip steel in the thickness direction, wherein one roll is formed with a wide shallow groove and narrow deep grooves at both ends of the shallow groove in the circumferential direction, and on the other roll. A first step of forming a groove in the circumferential direction at a location corresponding to the deep groove, or forming a location corresponding to the shallow groove as a high portion, and passing the strip steel between both rolls to form an I-shaped section;
From the second step of forming a high portion of a constant width in the circumferential direction and pressing the side end surface of the steel material formed in an I-shaped cross section in the width direction with a roll having unevenness formed on the high portion to form the unevenness on the side end surface A method for manufacturing a structural material for a groove lid, comprising: 11. A first convex portion having a width narrower than that of the strip steel and a second convex portion having a constant distance from the convex portion are circumferentially arranged between a pair of rolls for narrowing the strip steel in the thickness direction. The strip steel is passed between both rolls so as to protrude from the first protrusion and the second protrusion, the first protrusion forms an I-shaped cross section, and the second protrusion causes the strip steel to pass through. First step of forming the strip side end on the steel side into a ridge, and a ridge of a steel material formed in a cross-section I-shape by a roll having a high width of a certain width formed in the circumferential direction and irregularities formed on the peripheral surface of the high height. A method of manufacturing a structural member for a groove lid, which comprises a second step of pressing the end face in the width direction to form irregularities on the end face. 12. A shallow groove having a wide width on each side of a pair of rolls for narrowing the strip steel in the thickness direction, narrow deep grooves at both ends of the shallow groove, and a shallow groove adjacent to one of the deep grooves in the circumferential direction. The first step of forming the strip steel by passing the strip steel into the grooves of both rolls and forming one side end into a ridge, and forming a high portion with a constant width in the circumferential direction. The side end face of the steel material formed in the I-shaped cross section is pressed in the width direction with a roll having unevenness formed on the
A method for manufacturing a groove lid structural material, comprising a second step of forming irregularities on the side end surface. 13. A pair of rolls for narrowing the strip steel in the thickness direction, one roll having a wide shallow groove, both ends of the shallow groove having a narrow deep groove, and one narrow groove having a narrow width adjacent to the one deep groove. Along with forming a shallow groove in the circumferential direction, a groove is formed in the circumferential direction on the other roll at a location corresponding to the deep groove, or a location corresponding to the shallow groove is formed as a high portion, and between the rolls. First step of forming a strip-shaped steel into an I-shaped cross section, and forming a high portion with a constant width in the circumferential direction, and forming a concavo-convex roll on the high portion to form a side end surface of the steel material formed in the I-shaped section in the width direction A method of manufacturing a structural member for a groove lid, which comprises a second step of applying pressure to form irregularities on the side end surface.