JP6741268B2 - Manufacturing method and manufacturing apparatus for steel plate having embossed shape - Google Patents

Description

The present invention relates to a method and an apparatus for manufacturing a steel sheet having an embossed shape, and more particularly, to a method and an apparatus for manufacturing a steel sheet having a predetermined embossed shape by preforming and main forming.

Patent Document 1 describes a technique for forming an emboss on a metal strip.

In this technique, an emboss is formed on the metal band by passing the metal band between a pair of rolls included in the embossing roll.

JP, 2002-239629, A

With the conventional technique described in Patent Document 1, it is difficult to obtain an emboss with a sharp appearance. In the prior art, unless the embossed hole is formed with a shallow inclination, strain is likely to concentrate on a part of the metal strip, which causes damage such as cracking.

An object of the present invention is to provide a manufacturing method and a manufacturing apparatus capable of forming a steel sheet having an embossed shape with a sharp appearance and suppressing the occurrence of damage during the forming. ..

A method for manufacturing a steel sheet having an embossed shape according to one aspect of the present invention includes passing a steel sheet between a pair of first rolls, applying pressure to various portions of the steel sheet, and stretching the steel sheet while providing a plurality of preliminary recessed strips on the steel sheet. A preforming step of giving a predetermined corrugated shape in which a part is located at a distance in one direction, between a pair of second rolls, the corrugated shaped steel sheet is passed, and at various places of the steel sheet. A main forming step of giving a predetermined embossed shape in which a plurality of concave streak portions having a U-shaped cross section are located at a distance in the one direction by bending by applying pressure. The preliminary groove portions and the groove portions are in a one-to-one correspondence, and the depth of the preliminary groove portions is the same as the depth of the corresponding groove portions.

A method for manufacturing a steel sheet having an embossed shape according to another aspect of the present invention is to pass a steel sheet between a pair of first rolls, apply pressure to various portions of the steel sheet, and stretch the steel sheet while providing a plurality of preliminary recesses. A preforming step for giving a predetermined corrugated shape in which the strip portion is positioned with a distance in one direction, and between the pair of second rolls, the steel sheet provided with the corrugated shape is passed through, and various portions of the steel sheet are provided. A main forming step of giving a predetermined embossed shape in which a plurality of concave streak portions having a U-shaped cross section are located at a distance in the one direction by applying pressure to and bending the steel sheet. The preliminary groove portions and the groove portions have a one-to-one correspondence, and the depth of the preliminary groove portions is greater than the depth of the corresponding groove portions.

The depth of the groove is 2 mm to 4 mm, and the depth of the preliminary groove is 0.5 mm to 1.5 mm larger than the depth of the corresponding groove, and 5 mm or less. Is preferred.

An apparatus for producing a steel sheet having an embossed shape according to one aspect of the present invention preforms a steel sheet to form a pair of first rolls that give the steel sheet a predetermined corrugated shape, and preforms the preformed steel sheet. And a pair of second rolls that give the steel plate a predetermined embossed shape. The pair of first rolls is a mold structure that imparts the corrugated shape in which a plurality of preliminary concave streak portions are located at a distance in one direction to the steel sheet by applying pressure to various portions of the steel sheet and stretching the steel sheet. Have. The pair of second rolls have a mold structure that gives the embossed shape in which the plurality of concave streak portions having a U-shaped cross section are located at a distance in the one direction on the pre-formed steel plate. The preliminary groove portions and the groove portions are in a one-to-one correspondence, and the depth of the preliminary groove portions is the same as the depth of the corresponding groove portions.

An apparatus for manufacturing a steel sheet having an embossed shape according to another aspect of the present invention includes a pair of first rolls that preform a steel sheet to give the steel sheet a predetermined corrugated shape, and the preformed steel sheet. And a pair of second rolls that are formed to give the steel sheet a predetermined embossed shape. The pair of first rolls is a mold structure that imparts the corrugated shape in which a plurality of preliminary concave streak portions are located at a distance in one direction to the steel sheet by applying pressure to various portions of the steel sheet and stretching the steel sheet. Have. The pair of second rolls have a mold structure that gives the embossed shape in which the plurality of concave streak portions having a U-shaped cross section are located at a distance in the one direction on the pre-formed steel plate. The preliminary groove portions and the groove portions have a one-to-one correspondence, and the depth of the preliminary groove portions is greater than the depth of the corresponding groove portions.

INDUSTRIAL APPLICABILITY The method for producing a steel sheet having an embossed shape according to the present invention has an effect that an embossed shape having a sharp appearance can be formed, and damage during the forming can be suppressed.

The apparatus for manufacturing a steel sheet having an embossed shape according to the present invention has an effect that an embossed shape having a sharp appearance can be formed, and the occurrence of breakage during forming can be suppressed.

FIG. 1 is a side view schematically showing the manufacturing apparatus of the first embodiment. FIG. 2 is a front view schematically showing a pair of first rolls included in the above manufacturing apparatus. FIG. 3 is an enlarged view of part P of FIG. FIG. 4 is a front view schematically showing a pair of second rolls included in the above manufacturing apparatus. FIG. 5 is an enlarged view of the Q portion of FIG. FIG. 6 is an explanatory view showing the corrugated shape and the embossed shape in an overlapping manner. FIG. 7A is an explanatory view showing a corrugated shape set at an inclination angle α=25°, and FIG. 7B is an explanatory view showing an embossed shape molded through the corrugated shape of FIG. 7A. 8A is a diagram showing a strain distribution generated in the corrugated shape of FIG. 7A, and FIG. 8B is a diagram showing a strain distribution generated in the embossed shape of FIG. 7B. FIG. 9A is an explanatory view showing a corrugated shape set at an inclination angle α=38°, and FIG. 9B is an explanatory view showing an embossed shape molded through the corrugated shape of FIG. 9A. FIG. 10A is a diagram showing a strain distribution generated in the corrugated shape of FIG. 9A, and FIG. 10B is a diagram showing a strain distribution generated in the embossed shape of FIG. 9B. FIG. 11A is an explanatory view showing a corrugated shape set at an inclination angle α=53°, and FIG. 11B is an explanatory view showing an embossed shape molded through the corrugated shape of FIG. 11A. 12A is a diagram showing a strain distribution generated in the corrugated shape of FIG. 11A, and FIG. 12B is a diagram showing a strain distribution generated in the embossed shape of FIG. 11B. FIG. 13 is a diagram showing a steel sheet formed into an embossed shape by one roll forming. FIG. 14: is a figure which shows the strain distribution of the steel plate of FIG. FIG. 15: is a front view which shows schematically the principal part of the preforming machine with which the manufacturing apparatus of 2nd embodiment is equipped. FIG. 16: is a front view which shows roughly a mode that preforming is performed with the manufacturing apparatus same as the above. FIG. 17 is a front view schematically showing a main part of a main molding machine included in the above manufacturing apparatus. FIG. 18 is a front view schematically showing a state where main molding is performed by the above manufacturing apparatus. FIG. 19 is a diagram showing an analytical model of preforming performed by the above manufacturing apparatus. FIG. 20A is a diagram showing a strain distribution generated in a steel sheet after preforming under the condition of R1=R2=3.5 mm, and FIG. 20B is a diagram showing a strain distribution generated after further main-forming the steel sheet of FIG. 20A. Is. FIG. 21A is a diagram showing a strain distribution generated in the steel sheet after preforming under the condition of R1=R2=3.0 mm, and FIG. 21B is a diagram showing a strain distribution generated after further main-forming the steel sheet of FIG. 21A. Is. 22A is a diagram showing a strain distribution generated in a steel sheet after preforming under the condition of R1=R2=2.5 mm, and FIG. 22B is a diagram showing a strain distribution generated after further main forming the steel sheet of FIG. 22A. Is. FIG. 23A is a diagram showing a strain distribution generated in a steel sheet after preforming under a condition of R1=R2=1.5 mm, and FIG. 23B is a diagram showing a strain distribution generated after further main-forming the steel sheet of FIG. 23A. Is. FIG. 24 is a diagram showing a strain distribution of a steel sheet formed into a similar embossed shape by one-time forming. FIG. 25A is a graph showing the relationship between the stroke amount and the maximum strain after main forming under the conditions of β=80° and D2=3.0 mm, and FIG. 25B is β=70°, D2=3.0 mm. FIG. 25A is a graph showing the relationship between the stroke amount and the maximum strain after main forming under the conditions of FIG. 25A, and FIG. 25A shows the stroke amount and the maximum strain after main forming under conditions of β=60° and D2=3.0 mm. It is a graph figure which shows a relationship. FIG. 26 is a graph showing the relationship between the stroke amount and the maximum strain after main forming under the conditions of β=70° and D2=2.0 mm. FIG. 27 is a graph showing the relationship between the stroke amount and the maximum strain after main forming under the conditions of β=60° and D2=4.0 mm.

(First embodiment)
FIG. 1 shows an apparatus for manufacturing a steel sheet having an embossed shape according to the first embodiment.

Hereinafter, a steel plate having an embossed shape is referred to as an “embossed steel plate”, an apparatus for manufacturing the same is simply referred to as a “manufacturing apparatus”, and a method for manufacturing the same is simply referred to as a “manufacturing method”. The embossed steel sheet of this embodiment is used for various applications such as siding.

The manufacturing apparatus of the present embodiment sequentially performs the preforming and the main forming on the strip-shaped steel plate 9 to suppress the damage of the steel plate 9 and sharply emboss the steel plate 9 (see the solid line in FIG. 6). This is a molding device.

The manufacturing apparatus of this embodiment preforms the uncoiler 81 that sends out the strip-shaped steel plate 9, the side guide 82 that guides the steel plate 9 that is sent out from the uncoiler 81, and the thin plate-shaped steel plate 9 that is sent out from the uncoiler 81. A preforming machine 83 for performing the above, a main forming machine 84 for performing main forming on the preformed steel sheet 9, and a drawer roll 85 for further feeding out the main formed steel sheet 9.

The uncoiler 81, the side guide 82, the preforming machine 83, the main forming machine 84, and the pull-out roll 85 are arranged in this order along the feeding direction indicated by the white arrow in the drawing. The steel plate 9 delivered from the uncoiler 81 is a flat strip-shaped coated steel plate. The term "flat" used in the present text is not limited to a strictly flat meaning, and includes a substantially flat case.

The preforming machine 83 includes a pair of upper and lower first rolls 1. Below, the 1st roll 1 located in an upper side among a pair of 1st rolls 1 is called an "upper 1st roll", and the code|symbol 1a is attached|subjected. Of the pair of first rolls 1, the lower first roll 1 is referred to as a "lower first roll" and is denoted by reference numeral 1b.

An upper die 11a for preforming is provided on the outermost layer of the upper first roll 1a. A lower die 11b for preforming is provided on the outermost layer of the lower first roll 1b.

Both the upper mold 11a and the lower mold 11b for preforming are molds that continuously have a gentle unevenness such as a so-called sine wave (see FIG. 3). The steel sheet 9 is roll-formed until it reaches a predetermined corrugated shape F1 (see the chain line in FIG. 6) by being rolled out in the thickness direction 9). That is, the upper die 11a and the lower die 11b constitute the die structure 11 for preforming the steel sheet 9 into the corrugated shape F1.

The main molding machine 84 includes a pair of upper and lower second rolls 2. Of the pair of second rolls 2, the second roll 2 located on the upper side is referred to as an "upper second roll" and is denoted by reference numeral 2a. Of the pair of second rolls 2, the second roll 2 located on the lower side is referred to as a "lower second roll" and is denoted by reference numeral 2b.

An upper die 21a for main forming is provided on the outermost layer of the upper second roll 2a. A lower die 21b for main forming is also provided on the outermost layer of the lower second roll 2b.

Both the upper mold 21a and the lower mold 21b for main forming are molds that continuously have right-angled irregularities such as so-called rectangular waves (see FIG. 5). The steel plate 9 having the corrugated shape F1 is roll-formed until it reaches a predetermined emboss F2 by being fed while being rolled in the vertical direction. In other words, the upper die 21a and the lower die 21b constitute a die structure 21 for forming the steel sheet 9 into a predetermined embossed shape F2 (see the solid line in FIG. 6).

The steel plate 9 formed into the embossed shape F2 is cut into a predetermined size in a later step, whereby an embossed steel plate is obtained. The obtained embossed steel plate is used, for example, as metal siding. Alternatively, the obtained embossed steel sheet may have a core material and a sheet material laminated in this order in a subsequent step, and cut into a predetermined size to be used as the metal siding. The core material is a heat insulating material using, for example, foam resin, and the sheet material is, for example, a metal panel or a backing paper.

In the former case, the finally obtained metal siding is a coated steel plate formed into an embossed shape F2. In the latter case, the finally obtained metal siding is a sandwich panel in which a core material is sandwiched between a coated steel sheet formed into an embossed shape F2 and a sheet material.

Next, the corrugated shape F1 and the embossed shape F2 will be described in more detail.

In FIG. 6, the corrugated shape F1 and the embossed shape F2 are shown in an overlapping manner. The chain line in the drawing is the steel plate 9 having the corrugated shape F1, and the solid line in the drawing is the steel plate 9 having the embossing shape F2.

As shown in the drawing, the height of the unevenness (the height in the vertical direction) is the same in the steel plate 9 formed in the corrugated shape F1 and the steel plate 9 formed in the embossed shape F2. The term “identical” used in the present text is not limited to the same in a strict sense, and includes almost the same cases.

The corrugated shape F1 of the present embodiment is a shape in which the flat steel plate 9 is rolled in the up-down direction between the upper die 11a and the lower die 11b, and is stretched and bent to be formed. It has continuous gentle unevenness like a so-called sine wave.

The steel plate 9 formed in the corrugated shape F1 is curved in an arc shape so as to project in a predetermined direction (upward) and is curved in an arc shape so as to project in a direction opposite to the predetermined direction (downward). The preliminary concave streak portions 32 are alternately formed with the connecting walls 33.

The connecting wall 33 is an inclined portion that smoothly connects the adjacent preliminary convex streak portion 31 and the preliminary concave streak portion 32, and has an inclination angle α with respect to a plane (horizontal plane) orthogonal to the thickness direction (vertical direction) of the steel sheet 9. Only tilted position. The inclination angle α is, for example, 45°.

The embossed shape F2 of the present embodiment is a shape formed by rolling the steel plate 9 of the corrugated shape F1 in the up-down direction between the upper die 21a and the lower die 21b, and bending the steel sheet 9. It continuously has sharp unevenness like a so-called rectangular wave.

The steel plate 9 formed in the embossed shape F2 has a shape in which a plurality of recessed portions 41 having a U-shaped bent shape are lined up at a predetermined distance along one direction 900 (the width direction of the steel plate 9). is there.

Each recess 41 includes a flat bottom wall 411 and a pair of vertical walls 412 standing up from both ends in one direction of the bottom wall 411, and has a shape in which the opposite side (upper side) of the bottom wall 411 is open. A flat upper wall 42 is formed between the pair of recessed portions 41 that are adjacent in one direction.

The upper wall 42 is parallel to the bottom wall 411 of the groove 41 that is adjacent to the upper wall 42. The term “parallel” used in the present text is not limited to parallel in a strict sense, and includes the case of being substantially parallel.

According to the manufacturing apparatus of the present embodiment, first, the steel plate 9 is stretched and formed into the corrugated shape F1, and then the corrugated shape F2 is bent to reach the embossed shape F2. It is possible to obtain an embossed steel plate having a unique appearance.

In order to suppress the damage during molding more effectively, it is preferable to set the inclination angle α of the connecting wall 33 of the corrugated shape F1 in the range of 20° or more and 60° or less. A more preferable setting is to set the inclination angle α within a range of 30° or more and 45° or less.

Next, the strain distribution of the steel sheet 9 obtained by numerical analysis will be described. 7 to 12 show the strain distributions of the steel plate 9 generated in the corrugated shape F1 and the embossed shape F2 at a plurality of inclination angle α settings. The thickness of the steel plate 9 is set to 0.27 mm. As a comparative example, FIGS. 13 and 14 show strain distributions when the steel sheet 9 is formed into the embossed shape F2 by one roll forming.

As shown in FIG. 13 and FIG. 14, when the embossed shape F2 is formed by a single roll forming, tension and bending occur at the shoulder portion 45 at the same time, and tensile strain and bending strain are superposed. The thickness of the portion 45 is remarkably reduced, and breakage or breakage is likely to occur.

On the other hand, as shown in FIGS. 7 to 12, by performing the preforming before the main forming, it is possible to suppress the concentration of strain on the shoulder portion 45.

The examples shown in FIGS. 7 and 8 are examples in which the inclination angle α of the steel plate 9 having the corrugated shape F1 is set to 25°, and the radius of curvature of the shoulder portion 35 is 10.0 mm. This radius of curvature is larger than the radius of curvature (=1.0 mm) of the shoulder portion 45 of the embossed shape F2.

The examples shown in FIGS. 9 and 10 are examples in which the inclination angle α of the steel plate 9 having the corrugated shape F1 is set to 38°, and the radius of curvature of the shoulder portion 35 is 3.0 mm. This radius of curvature is larger than the radius of curvature (=1.0 mm) of the shoulder portion 45 of the embossed shape F2.

The examples shown in FIGS. 11 and 12 are examples in which the inclination angle α of the corrugated steel sheet 9 is set to 53°, and the radius of curvature of the shoulder portion 35 is 1.5 mm. This radius of curvature is larger than the radius of curvature (=1.0 mm) of the shoulder portion 45 of the embossed shape F2.

From the above calculation results, it is understood that the steel plate 9 is formed into the embossed shape F2 by the pre-forming and the main forming more easily than the steel sheet 9 is formed into the embossed shape F2 by the roll forming once.

Further, even in the case of performing the preforming and the main forming, it is understood that the damage is less likely to occur when the inclination angle α is further set within the range of 30° to 45°. When the inclination angle α is smaller than 30°, strain concentration is likely to occur in the shoulder portion 45 during the main forming. When the inclination angle α exceeds 45°, strain concentration is likely to occur in the shoulder portion 35 during preforming.

When the allowable range of the thickness reduction of the shoulder portion 45 is within 50%, the inclination angle α may be set within the range of 20° or more and 60° or less.

Similar results are confirmed in the experiment.

(Second embodiment)
Next, a manufacturing apparatus and a manufacturing method of the second embodiment will be described based on FIGS. 15 to 27.

In addition, about the structure similar to 1st embodiment among the structures of this embodiment, the same code|symbol is attached|subjected and detailed description is abbreviate|omitted. In the following, a configuration different from that of the first embodiment will be described in detail.

The manufacturing apparatus of the present embodiment is provided with an upper mold 11a for preforming and a lower mold 11b, the main parts of which are shown in FIGS. 15 and 16, and further, for the main molding whose main parts are shown in FIGS. The upper mold 21a and the lower mold 21b are provided.

The upper die 11a for preforming has a plurality of convex portions 115a having an arcuate cross-section that are pressed against the steel plate 9 in the thickness direction (downward) at a distance in one direction 900. The radius R1 of the convex portion 115a is, for example, 3.5 mm.

The lower die 11b for preforming has a plurality of convex portions 115b having an arcuate cross-section that are pressed against the steel plate 9 in the thickness direction (upward) at a distance in one direction 900. The radius R2 of the convex portion 115b is, for example, 3.5 mm.

In one direction 900, the convex portions 115a of the upper mold 11a and the convex portions 115b of the lower mold 11b are alternately positioned with a predetermined pitch P1. The predetermined pitch P1 may be different or the same between the adjacent convex portions 115a and 115b.

In the preforming step, from the state where the upper convex portion 115a hits the upper surface of the steel plate 9 and the lower convex portion 115b hits the lower surface of the steel plate 9, as shown by the white arrow in FIG. The portion 115a moves downward relative to the lower convex portion 115b. A stroke amount S1 by which the upper convex portion 115a relatively moves downward is 4.5 mm, for example.

As shown in FIG. 16, a portion of the steel plate 9 against which the upper convex portion 115a is pressed serves as a preliminary concave streak portion 32 which is recessed downward in an arc shape. The portion of the steel plate 9 against which the lower convex portion 115b is pressed serves as the preliminary ridge portion 31 that protrudes upward in an arc shape.

In the preforming step, elongation is evenly applied to the entire steel plate 9 and gentle bending is applied to the entire steel plate 9, so that the preliminary concave streak portion 32 and the preliminary convex streak portion 31 move in one direction 900. A smooth corrugated shape F1 such as a sine wave, which is alternately arranged at, is formed. In one direction 900, the length of the steel plate 9 formed into the corrugated shape F1 is substantially the same as the length of the flat steel plate 9 before preforming.

In the corrugated shape F1, the depth D1 of the preliminary groove portion 32 is equal to the stroke amount S1 in the preforming step, and is, for example, 4.5 mm.

As shown in FIGS. 17 and 18, the upper mold 21a for main molding has a rectangular wave in which a convex portion 215a having a U-shaped cross section and a concave portion 217a having a U-shaped cross section are alternately provided in one direction 900. It has a cross-sectional shape like.

The lower mold 21b for main molding has a cross-sectional shape like a rectangular wave in which convex portions 215b having a U-shaped cross section and concave portions 217b having a U-shaped cross section are alternately provided in one direction 900.

The upper mold 21a and the lower mold 21b have dimensions and shapes that match each other.

The convex portion 215a of the upper mold 21a corresponds to the concave portion 217b of the lower mold 21b one to one. Corresponding convex portion 215a and concave portion 217b have a positional relationship of vertically facing each other and have dimensions and shapes that match each other.

The concave portion 217a of the upper mold 21a corresponds to the convex portion 215b of the lower mold 21b one to one. Corresponding concave portion 217a and convex portion 215b are in a vertically opposed positional relationship, and have dimensions and shapes that match each other.

Further, the convex portions 215a of the upper mold 21a for main molding have a one-to-one correspondence with the convex portions 115a of the upper mold 11a for preforming. The convex portion 215b having a U-shaped cross section of the lower mold 21b for main molding has a one-to-one correspondence with the convex portion 115b of the lower mold 11b for preforming.

In one direction 900, the convex portions 215a of the upper mold 21a and the convex portions 215b of the lower mold 21b are alternately positioned with a predetermined pitch P2. The pitch P2 between the convex portions 215a and 215b in the main forming step is the same as the pitch P1 between the convex portions 115a and 115b in the preforming step corresponding to the convex portions 215a and 215b, and is, for example, 7 mm.

In the main forming step, from the state in which the upper convex portion 215a hits the upper surface of the steel sheet 9 formed in the corrugated shape F1 and the lower convex portion 215b hits the lower surface of the steel sheet 9, the state shown in FIG. As shown by a white arrow, the upper die 21a moves downward relative to the lower die 21b. The stroke amount by which the upper mold 21a relatively moves downward is, for example, 1.5 mm.

At this time, the top portion 312 of the preliminary convex strip portion 31 of the steel plate 9 having the corrugated shape F1 hits the concave portion 217a of the upper die 21a and is pushed downward, and from the top portion 322 of the preliminary concave strip portion 32 of the steel plate 9. The portion 324 that is close to the preliminary convex streak portion 31 hits the corner portion of the convex portion 215a of the upper mold 21a and is pushed downward.

Similarly, the top 322 of the preliminary recessed portion 32 of the corrugated F1 steel plate 9 is pressed against the recessed portion 217b of the lower mold 21b, and the top of the spare protrusion 31 of the steel plate 9 is spared from the top 312. The portion 314 near the recessed portion 32 presses against the corner portion of the convex portion 215b of the lower mold 21b.

As a result, the steel plate 9 preformed into the corrugated shape F1 is finally formed into the embossed shape F2 as shown in FIG. In one direction 900, the length of the steel sheet 9 formed into the embossed shape F2 is substantially the same as the length of the steel sheet 9 before and after preforming.

The concave streak portion 41 of the steel plate 9 having the embossed shape F2 is rolled up and down between the convex portion 215a of the upper mold 21a and the concave portion 217b of the lower mold 21b, and is bent to have a cross section. It is a portion formed in a U shape.

The plurality of groove portions 41 of the steel plate 9 having the embossed shape F2 have a one-to-one correspondence with the plurality of preliminary groove portions 32 of the steel plate 9 having the corrugated shape F1. The depth D2 of the groove 41 is smaller than the corresponding depth D1 of the preliminary groove 32. That is, when comparing the steel plate 9 in the stage preformed into the corrugated shape F1 and the steel plate 9 in the stage fully formed into the embossed shape F2, the unevenness is formed deeper in the preforming stage.

According to the manufacturing apparatus of the present embodiment, first, the steel plate 9 is evenly and greatly stretched to form the corrugated shape F1 and then bent up to the embossed shape F2 while being crushed in the vertical direction. It is possible to suppress the concentration of strain and damage.

In addition, in the main forming step, when the steel plate 9 having the corrugated shape F1 is rolled between the upper mold 21a and the lower mold 21b, the upper and lower tops 312 and 322 of the steel plate 9 are pushed vertically. Be done. Of the preliminary ridges 31 of the steel plate 9, a portion 314 that bends by hitting a corner portion of the lower die 21b and a portion 324 that bends by hitting a corner portion of the upper die 21a tend to have concentrated strains and the thickness thereof tends to decrease. As for the portions, compressive strain is applied to these portions 314 and 324 from the side of the top portions 312 and 322, and the material flows in, whereby strain concentration and thickness reduction are suppressed.

Next, the strain distribution of the steel plate 9 obtained by numerical analysis will be described.

The analysis here is performed by using the model shown in FIG. 19 and changing the radii R1 and R2 of the convex portions 115a and 115b in the preforming in a plurality of steps, and further, the stroke amount S1 of the convex portion 115a (that is, the preliminary concave groove). The depth D1) of the portion, the depth D2 of the recess 41 after the main forming, and the inclination angle β of the vertical wall 412 were changed in a plurality of steps. The pitch P1 between the convex portions 115a and 115b was fixed at 7 mm.

The results shown in FIGS. 20A to 23B are calculated by calculating the strain distribution of the steel plate 9 generated in the corrugated shape F1 and the embossed shape F2 while changing the radii R1 and R2 between 3.5 and 1.5 mm. ..

FIG. 24 shows, as a comparative example, the strain distribution when the steel sheet 9 is formed into the same embossed shape F2 by one-time forming (main forming only) as in the conventional technique. As shown in FIG. 24, when the embossed shape F2 is formed by one-time molding, the strain is concentrated on the rectangular wave-shaped shoulders and the vertical wall portions, and breakage or other damage is likely to occur. In the result of FIG. 24, the maximum strain is 57.5%.

On the other hand, as shown in FIGS. 20A to 23B, by performing preforming before the main forming, it is possible to prevent strain from being concentrated on a specific portion of the steel sheet 9.

In FIG. 20A and FIG. 20B, the conditions for preforming are set to radius R1=R2=3.5 mm and stroke amount S1=4.5 mm, and the conditions for main forming are depth D2=3 mm and inclination angle β= The result when 70° is set is shown. In this case, the maximum strain in the embossed shape F2 of FIG. 20B is 41.4%.

Similarly, in FIGS. 21A and 21B, the condition for preforming is set to radius R1=R2=3.0 mm and the stroke amount S1=4.5 mm, and the condition for main forming is depth D2=3 mm and inclination. The result when the angle β is set to 70° is shown. In this case, the maximum strain in the embossed shape F2 of FIG. 21B is 35.0%.

In FIG. 22A and FIG. 22B, the conditions for preforming are set to radius R1=R2=2.5 mm and stroke amount S1=4.5 mm, and the conditions for main forming are depth D2=3 mm and inclination angle β= The result when 70° is set is shown. In this case, the maximum strain in the embossed shape F2 of FIG. 22B is 32.5%.

In FIGS. 23A and 23B, conditions for preforming are set to radius R1=R2=1.5 mm, stroke amount S1=4.5 mm, conditions for main forming are depth D2=3 mm, inclination angle β= The result when 70° is set is shown. In this case, the maximum strain in the embossed shape F2 of FIG. 23B is 38.8%.

Also from the above analysis results, rather than forming the steel sheet 9 into the embossed shape F2 by a single forming as shown in FIG. 24, the steel sheet 9 is once stretched to a corrugated shape F1 by preforming, and then the steel sheet is formed by the main forming. It can be seen that the strain concentration can be suppressed by forming the rectangular wave-shaped embossed shape F2 while crushing 9 up and down.

Further, from the above analysis results, it is understood that when the radii R1 and R2 of the convex portions 115a and 115b in the preforming change, the strain concentration portion of the steel plate 9 having the corrugated shape F1 changes. In general, the smaller the radii R1 and R2, the closer the strain concentration portion is to the tops 312 and 322 of the preliminary convex streak portion 31 and the preliminary concave streak portion 32.

Therefore, if the strain-concentrated portion of the corrugated shape F1 of the steel sheet 9 is provided away from the corner of the embossed shape F2 (the portion that becomes the rectangular corrugated shoulder), the specific portion of the steel sheet 9 after the main forming It is possible to prevent strain from concentrating on the.

For example, when the corrugated shape F1 obtained by preforming is a shape close to a sine wave, distortion due to rolling tends to concentrate in the intermediate region between the convex portion and the concave portion, but the corrugated shape obtained by preforming When the shape F1 is a shape in which a straight line portion is present between the convex portion and the concave portion at a large ratio, the strain due to the rolling process is likely to be concentrated in the convex portion and the concave portion. In the latter case, in the main forming after the preforming, the straight part of the corrugated shape F1 is subjected to the rolling process, so that the steel plate 9 formed into the embossed shape F2 has the strain dispersed throughout the steel plate 9 to improve the workability. Contribute to improvement.

The following Tables 1 and 2 show the maximum strain and the reduction rate in the embossed shape F2 after the main forming when the analysis was performed while changing each condition stepwise. The value of the reduction rate indicates the rate at which the maximum strain was reduced by preforming, with the maximum strain when the steel sheet 9 was formed into the embossed shape F2 only by the main forming (Comparative Example) as 1.

The graphs shown in FIGS. 25A to 25C are graphs summarizing how the maximum strain after the main forming changes according to the change in the stroke amount S1 in the preforming.

FIG. 25A shows the case where the vertical wall 412 after the main molding has an inclination angle β=80° and the depth D2 of the concave portion 41 is 3.0 mm. FIG. 25B shows a case where the inclination angle β after main forming is 70° and the depth D2 of the concave streak portion 41 is 3.0 mm. FIG. 25C shows the case where the inclination angle β after main forming is 60° and the depth D2 of the groove 41 is 3.0 mm.

From these graphs as well, the stroke amount S1 in preforming (that is, the depth D1 of the preliminary groove portion 32) was set to be larger than the depth D2 (=3.0 mm) of the groove portion 41 after main molding. It can sometimes be seen that the maximum strain is reduced. In addition, when the stroke amount S1 (the depth D1 of the preliminary groove portion 32) is set within the range of 3.5 to 4.5 mm in any of the inclination angle β=80°, 70°, and 60° That is, it can be seen that the maximum strain is effectively reduced when the depth D2 of the groove 41 is set within the range of 0.5 to 1.5 mm. Furthermore, when the stroke amount S1 (depth D1) is set within the range that exceeds the depth D2 of the recessed portion 41 by 1.0 to 1.5 mm, the maximum strain can be more effectively reduced. Recognize.

The graph shown in FIG. 26 shows that after the main forming, when the inclination angle β after the main forming is 70° and the depth D2 of the concave portion 41 is 2.0 mm, the stroke amount S1 in the preforming is changed. 4 is a graph summarizing how the maximum strain value of changes. As shown in Table 2, when the inclination angle β is 70° and the depth D2 is 2.0 mm, the maximum strain is 38.4% in the comparative example in which only the main forming is performed.

From this graph, even when D2=2.0 mm, the stroke amount S1 (depth D1 of the preliminary groove portion 32) exceeds the depth D2 of the groove portion 41 by 0.5 to 1.5 mm (that is, It can be seen that the maximum strain is effectively reduced when set within the range of 2.5 to 3.5 mm). Furthermore, the stroke amount S1 (the depth D1 of the preliminary groove portion 32) exceeds the depth D2 of the groove portion 41 by 1.0 to 1.5 mm (that is, within the range of 3.0 to 3.5 mm). It can be seen that the maximum strain is more effectively reduced when set with (1).

The graph shown in FIG. 27 shows that when the inclination angle β after main forming is 60° and the depth D2 of the groove 41 is 4.0 mm, after the main forming according to the change in the stroke amount S1 in the preforming. 6 is a graph summarizing how the maximum strain of changes. As shown in Table 2, when the inclination angle β=60° and the depth D2=4.0 mm, the maximum strain is 66.1% in the comparative example in which only the main forming is performed.

From this graph, even when D2=4.0 mm, the stroke amount S1 (depth D1 of the preliminary groove portion 32) exceeds the depth D2 of the groove portion 41 by 0.5 to 1.0 mm (that is, It can be seen that the maximum strain is effectively reduced when set within the range of 4.5 to 5.0 mm). The maximum strain greatly increases when the stroke amount S1 exceeds 5 mm due to a molding limit.

In summary, when the depth D2 of the groove 41 is in the range of 2.0 to 4.0 mm, the stroke amount S1 (depth D1 of the preliminary groove 32) is the depth of the groove 41. When D2 is set to a range of 0.5 to 1.5 mm (more preferably 1.0 to 1.5 mm) and 5 mm or less, the maximum strain after the main forming is effectively reduced. ..

Further, from the results shown in Table 1 and Table 2, when the inclination angle α after preforming is set within the range of 30 to 50° (more preferably 34.2 to 41.4°), a large reduction rate is obtained. It can be seen that

Similar results are confirmed in the experiment.

As described above with reference to the accompanying drawings, the manufacturing method of the first embodiment includes a preforming step and a main forming step.

In the preforming step, the steel plate 9 is passed between the pair of first rolls 1 and a plurality of pre-recessed ridges 32 are formed in the steel plate 9 in one direction 900 while stretching the steel plate 9 by applying pressure to various parts of the steel plate 9. Is a step of providing a predetermined corrugated shape F1 located at the position.

In the main forming step, the steel plate 9 provided with the corrugated shape F1 is passed between the pair of second rolls 2, and pressure is applied to each part of the steel plate 9 to bend the steel plate 9 in a U-shaped cross section. This is a step of giving a predetermined embossed shape F2 in which a plurality of recessed portions 41 are spaced apart in one direction 900.

The preliminary groove portions 32 and the groove portions 41 have a one-to-one correspondence, and the depth D1 of the preliminary groove portions 32 is the same as the corresponding depth D2 of the groove portions 41.

Therefore, according to this manufacturing method, the flat steel plate 9 is sequentially subjected to the preforming step and the main step, and in the preforming step, the steel sheet 9 is evenly stretched to form the corrugated shape F1 and then Since it is bent into the embossed shape F2 having the same depth, it becomes possible to form the steel sheet 9 into the embossed shape F2 having a sharp appearance while suppressing the concentration of strain on a specific portion of the steel sheet 9 during forming.

Moreover, the manufacturing method of the second embodiment includes a preforming step and a main forming step.

In the preforming step, the steel sheet 9 is passed between the pair of first rolls 1 and a plurality of pre-recessed ridges are formed in the steel sheet 9 in one direction 900 while stretching the steel sheet 9 by applying pressure to various portions of the steel sheet 9. It is a step of providing a predetermined corrugated shape F1 to be positioned.

In the main forming step, the steel plate 9 provided with the corrugated shape F1 is passed between the pair of second rolls 2, and pressure is applied to each part of the steel plate 9 to bend the steel plate 9 in a U-shaped cross section. This is a step of giving a predetermined embossed shape F2 in which a plurality of recessed portions 41 are spaced apart in one direction 900.

The preliminary groove portions 32 and the groove portions 41 are in one-to-one correspondence, and the depth D1 of the preliminary groove portions 32 is larger than the corresponding depth D2 of the groove portions 41.

Therefore, according to this manufacturing method, the preforming step and the main step are sequentially performed on the flat steel sheet 9, and the steel sheet 9 is evenly stretched in the preforming step to form the corrugated shape F1. Also, since it is bent into the embossed shape F2 having a shallow unevenness, it becomes possible to form the steel sheet 9 into the embossed shape F2 having a sharp appearance while suppressing the concentration of strain on a specific portion of the steel sheet 9 during forming.

In the manufacturing method of the second embodiment, the depth D2 of the groove 41 is 2 mm to 4 mm, and the depth D1 of the preliminary groove 32 is larger than the depth D2 of the corresponding groove 41. It is preferably larger by 0.5 mm to 1.5 mm and smaller than 5 mm.

By setting the depths D1 and D2 in this manner, it is possible to effectively suppress the concentration of strain on a specific portion of the steel sheet 9 after the main forming.

Further, the manufacturing apparatus of the first embodiment preforms the steel plate 9 and performs main forming of the pair of first rolls 1 that gives the steel plate 9 a predetermined corrugated shape F1, and the preformed steel plate 9, The steel plate 9 is provided with a pair of second rolls 2 that give a predetermined embossed shape F2.

The pair of first rolls 1 apply pressure to various portions of the steel plate 9 to extend the steel plate 9, thereby providing the steel plate 9 with a corrugated shape F1 in which the plurality of preliminary recessed portions 32 are positioned at a distance in one direction 900. It has a mold structure 11.

The pair of second rolls 2 has a die structure 21 that gives the pre-formed steel plate 9 an embossed shape F2 in which a plurality of concave streak portions 41 having a U-shaped cross section are located at a distance in one direction 900. ..

The preliminary groove portions 32 and the groove portions 41 have a one-to-one correspondence, and the depth D1 of the preliminary groove portions 32 is the same as the corresponding depth D2 of the groove portions 41.

Therefore, according to this manufacturing apparatus, the preforming step and the main step are sequentially performed on the flat steel sheet 9, and the steel sheet 9 is evenly stretched in the preforming step to form the corrugated shape F1. Since it is bent into the embossed shape F2 having the same depth, it becomes possible to form the steel sheet 9 into the embossed shape F2 having a sharp appearance while suppressing the concentration of strain on a specific portion of the steel sheet 9 during forming.

Further, the manufacturing apparatus of the second embodiment preforms the steel plate 9, and then main-forms the pair of first rolls 1 that give the steel plate 9 a predetermined corrugated shape F1, and the preformed steel plate 9, The steel plate 9 is provided with a pair of second rolls 2 that give a predetermined embossed shape F2.

The pair of first rolls 1 apply pressure to various portions of the steel plate 9 to extend the steel plate 9, thereby providing the steel plate 9 with a corrugated shape F1 in which the plurality of preliminary recessed portions 32 are positioned at a distance in one direction 900. It has a mold structure 11.

The pair of second rolls 2 has a die structure 21 that gives the pre-formed steel plate 9 an embossed shape F2 in which a plurality of concave streak portions 41 having a U-shaped cross section are located at a distance in one direction 900. ..

The preliminary groove portions 32 and the groove portions 41 are in one-to-one correspondence, and the depth D1 of the preliminary groove portions 32 is larger than the corresponding depth D2 of the groove portions 41.

Therefore, according to this manufacturing apparatus, the preforming step and the main step are sequentially performed on the flat steel sheet 9, and the steel sheet 9 is evenly stretched into the corrugated shape F1 in the preforming step. Since it is bent into the embossed shape F2 having a shallow unevenness, it becomes possible to form the steel sheet 9 into the embossed shape F2 having a sharp appearance while suppressing the concentration of strain on a specific portion of the steel sheet 9 during forming.

Although the manufacturing method and the manufacturing apparatus for the embossed steel sheet have been described above, the manufacturing method and the manufacturing apparatus for the embossed steel sheet are not limited to the above-described embodiments, and those that have been subjected to appropriate design changes and application of known technology are also available. , Included in the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 1 1st roll 11 Mold structure 2 2nd roll 21 Mold structure 31 Preliminary convex ridge part 41 Recessed ridge part 9 Steel plate 900 One direction D1 depth D2 depth F1 corrugated shape F2 embossed shape

Claims (5)

A predetermined wave in which a plurality of preliminary concave streak portions and a plurality of preliminary convex streak portions are alternately positioned on the steel plate while passing a steel plate between a pair of first rolls and applying pressure to various portions of the steel plate to extend the steel plate. A preforming step to give a mold shape,
Between the pair of second rolls, the corrugated shape is passed through the steel plate, and pressure is applied to each part of the steel plate to bend the steel plate, and thus the steel plate is provided with a plurality of concave stripes having a U-shaped cross section. but and a main forming step of providing a predetermined emboss shape is located at a distance to one direction,
Said concave portion and the preliminary concave groove portion is a one-to-one correspondence, the depth of the preliminary concave portion, Ri depth and same der of the concave portion corresponding thereto,
In the main forming step, a portion of the steel plate having the corrugated shape, which is closer to the preliminary ridge portion side than the shoulder portion of the preliminary concave portion, is a shoulder portion of the embossed concave portion. It is characterized in that a rolling process is performed so that
A method for manufacturing a steel sheet having an embossed shape. A predetermined wave in which a plurality of preliminary concave streak portions and a plurality of preliminary convex streak portions are alternately positioned on the steel plate while passing a steel plate between a pair of first rolls and applying pressure to various portions of the steel plate to extend the steel plate. A preforming step to give a mold shape,
Between the pair of second rolls, the corrugated shape is passed through the steel plate, and pressure is applied to each part of the steel plate to bend the steel plate, and thus the steel plate is provided with a plurality of concave stripes having a U-shaped cross section. but and a main forming step of providing a predetermined emboss shape is located at a distance to one direction,
Said concave portion and the preliminary concave groove portion is a one-to-one correspondence, the depth of the preliminary concave groove portion is much larger than the depth of the concave portion corresponding thereto,
In the main forming step, a portion of the steel plate having the corrugated shape, which is closer to the preliminary ridge portion side than the shoulder portion of the preliminary concave portion, is a shoulder portion of the embossed concave portion. It is characterized in that a rolling process is performed so that
A method for manufacturing a steel sheet having an embossed shape. The depth of the groove is 2 mm to 4 mm,
The depth of the preliminary groove portion is larger than the depth of the corresponding groove portion by 0.5 mm to 1.5 mm and is 5 mm or less.
A method for manufacturing a steel sheet having the embossed shape according to claim 2. Pre-forming the steel sheet, a pair of first rolls to give the steel sheet a predetermined corrugated shape,
Mainly forming the steel sheet after preforming, and a pair of second rolls to give a predetermined embossed shape to the steel sheet, and,
The pair of first rolls,
By applying pressure to various portions of the steel sheet and stretching it, the steel sheet has a mold structure that gives the corrugated shape in which a plurality of preliminary concave streak portions and a plurality of preliminary convex streak portions are alternately positioned,
The pair of second rolls,
The steel sheet after preforming, comprises a mold structure providing the emboss shape in which a plurality of concave portions is a U-shaped cross section is positioned at a distance to one direction,
Said concave portion and the preliminary concave groove portion is a one-to-one correspondence, the depth of the preliminary concave portion, Ri depth and same der of the concave portion corresponding thereto,
The mold structure of the pair of second rolls, a portion of the steel plate having the corrugated shape, which is closer to the side of the preliminary ridge than the shoulder of the preliminary ridge, the embossed shape. It is characterized in that it is configured to be a shoulder of the recessed portion ,
Equipment for manufacturing steel plates with embossed shape. Pre-forming the steel sheet, a pair of first rolls to give the steel sheet a predetermined corrugated shape,
Mainly forming the steel sheet after preforming, and a pair of second rolls to give a predetermined embossed shape to the steel sheet, and,
The pair of first rolls,
By applying pressure to various portions of the steel sheet and stretching it, the steel sheet has a mold structure that gives the corrugated shape in which a plurality of preliminary concave streak portions and a plurality of preliminary convex streak portions are alternately positioned,
The pair of second rolls,
The steel sheet after preforming, comprises a mold structure providing the emboss shape in which a plurality of concave portions is a U-shaped cross section is positioned at a distance to one direction,
Said concave portion and the preliminary concave groove portion is a one-to-one correspondence, the depth of the preliminary concave groove portion is much larger than the depth of the concave portion corresponding thereto,
The mold structure of the pair of second rolls, a portion of the steel plate having the corrugated shape, closer to the side of the preliminary ridge than the shoulder of the preliminary ridge, the embossed shape. Characterized in that it is configured to be a shoulder portion of the recessed line portion ,
Equipment for manufacturing steel plates with embossed shape.