MXPA98002420A - Method for laminating a steel bar for concrete reinforcement and a roller for the steel bar for reinforcement of concrete - Google Patents

Abstract

A steel bar for concrete reinforcement is produced, having knots and four ribs on its surface, making the final finishing laminate through a two-roll mill. The rollers R1, R2 of the two roll mill have a roll gauge (3), round gauges (2) and a bottom groove (1). The roll gauge (3) is substantially semicircular in cross section, and is provided on the entire peripheral surface of the roll. The round gauges (2) are made in the groove surface of the roll gauge (3) and have a predetermined width in order to cross the roll gauge (3). The cross section of the bottom groove (1) is an isosceles trapezoid and the groove (1) is provided along the center line of the roll gauge (3) over the entire circumference of the roll caliber.

Description

METHOD FOR LAMINATING A STEEL BAR FOR CONCRETE REINFORCEMENT AND A ROLLER FOR THE STEEL BAR FOR CONCRETE REINFORCEMENT DESCRIPTION TECHNICAL FIELD The present invention relates to a method of rolling to obtain a steel bar for concrete reinforcement and, more particularly. refers to ur. method able to obtain steady r. a steel bar for the concrete reinforcement that has ribs extending in a longitudinal direction through a 2-roll mill and a roller used in this process.

ANTECEDENTS OF THE TECHNIQUE Figure 6 shows a typical existing steel bar for a concrete reinforcement. In the Figure 6, (a) is a view in lateral elevation and (b) is a cross-sectional view, taken along the line X-X in (a). The steel bar for the concrete reinforcement 5 has a plurality of protrusions (knots) 12 formed on a circumferential surface of a round bar material along a circumferential direction substantially at an equal distance in the longitudinal direction. In addition, two protrusions (ribs) 4 are formed along the longitudinal direction and positions separated by 180 ° and the circumferential direction of a circle in cross section 1. The steel bar for concrete reinforcement is produced by means of a final finishing laminate mill of a co-heating lamination plant, where a plurality of two-roll rolling mills are arranged and laminated using finishing rollers R ^. , F.2 as shown in Figure 7 and Figure E. Figure 7 is a front elevational view illustrating an arrangement of both finishing rollers, and Figure 8 (a) is a developed view for a circumferential surface? E roller, and (b) is a cross-sectional view taken at along the line YY in (a). As can be seen from the figures, the roll gauge 3 having a substantially semicircular transverse shape is formed over the entire circumferential direction of both finishing rolls R ^ and R2 to form a step for the final finishing. In addition, a gauge surface of the roll gauge 3 is provided with round gauges 2 perpendicular to the roll gauge 3. Then, it passes a material S laminated in an elliptical cross section through a row of current rolling mills. up through a defi ned pass with both of the finishing rollers R ^ and ^ ¡- ^ e form the knots 12 corresponding to the round calipers 2 and the ribs 4 formed by the material that fills the gap between rollers R-_ and R2 - In addition, the knots of the steel bar for concrete reinforcement are sometimes arranged obliquely in the longitudinal direction. In this case, as shown in Figure 9, the round gauges 2 of the finishing roll R are formed by being inclined through a predetermined angle a with respect to the circumferential direction. In Figure 9, (a) is a developed view for a circumferential surface of the finishing roller R, and (b) is a cross-sectional view taken along the Z-Z line thereof. Also in this case, the ribs of the steel bar stop the obtained concrete reinforcement, only being the two ribs formed by the metal that fills a gap between the finishing rollers R. In recent years, the steel bar for concrete reinforcements has been tilted through a manufacturing machine. In this case, if only ribs exist, it is difficult to stably support the surface of the steel bar for reinforcement of concrete through a feeding device or a support device of the manufacturing machine. Pe: consequently, a bar has been demanded for the concrete reinforcement to have four ribs substantially at an equal distance in the circumferential direction. Also if the ribs are present in four, also provide a merit to increase adhesion with concrete. However, a technique to produce a steel bar for concrete reinforcement that has four ribs has not been established. For example, according to the technique previously presented by the applicant of the present and the like (referred to Japanese Patent Laid-open Publication Hei 7-32302), although a steel bar for reinforcement of concrete with four ribs can be Produced using a 4-roll rolling mill as a finishing mill, this technique increases the cost. Furthermore, the formation of four ribs by applying the final finishing laminate through a roller mill has not yet been put into practical use. The present invention has been achieved in view of the foregoing points and object to obtain a steel bar for reinforcement of concrete provided with knots and four ribs by applying the finished finishing to the two rolls of rolling mill.

DESCRIPTION OF THE INVENTION A method for laminating a steel bar for concrete reinforcement in accordance with the present - invention has a feature, a method for laminating a steel bar for concrete reinforcement to form knots or ribs on a circumferential surface of a material supplied by a final finishing rolling mill of a continuous heat rolling plant, wherein a plurality of two roller rolling mills is arranged in series, wherein the final finishing laminate is made through a pair of two rollers, each having a roller gauge having a substantially semicircular transverse shape, completely in the circumferential direction on the circumferential surface of the roll, round gauges formed in order to pass through the roll gauge on the surface of the roll gauge, and a bottom groove having a substantially trapezoidal cross-sectional shape and having an aperture width greater than the bottom width, and formed completely over the circumferential direction It moves towards the central portion in the direction of the gauge width of the roll gauge, thus forming four ribs through the metal that fills the gap between the rolls and the metal flow to the bottom groove. According to this method, two ribs are formed through metal flow in the bottom groove formed in each of the rollers in addition to the two ribs formed by the metal filling from the gap between the rollers. Since the ribs formed by the bottom groove are arranged in the central portion in the direction of the width of the roll gauge gauge, a steel bar for concrete reinforcement is obtained having four ribs formed at an equal distance or one distance substantially equal in the circumferential direction. Furthermore, for example as shown in Figure 1, the rollers are arranged so that the end surface of the bottom groove 1 and the bottom surface of the round gauges 2 are aligned, and the round gauges 2 and the gauge of roll 3 are in perpendicular angle and, as shown in Figure 2, it is preferred to perform the rolling while fixing the condition that the width of H ^ between the ribs 4a and 4b formed by the metal filling and the metal flow is aligned or substantially aligned with the diameter Ai of a transverse circle of round gauge 2. According to this method, the four ribs are each formed at an equal distance or a substantially equal distance in the circumferential direction, as well as also the outer circumferential surface of all the ribs is aligned or substantially aligned with the outer circumferential surface of the knot, and the knot is formed at a right angle to the knot. ostilla. Further, as shown in Figure 2, the roll is preferably adapted so that the depth of the bottom groove 1 is 10% or less of an average diameter of a product, the bottom groove 1 has a cross-sectional shape trapezoidal s is isosceles, an angle made between the two non-parallel sides is 10 ° or more, and the background width b of the bottom groove 1 is 4% or more the average diameter.- In addition, the substantially trapezoidal shape and the substantially isosceles trapezoidal shape means forms in which the two parallel sides of the trapezoid (not including the parallelogram and the isosceles trapezoid are not strictly linear, but are coaxially arched.) A shorter arc forms the bottom surface of the trapezoid. bottom groove, while the longer one forms the opening In addition, the average diameter of the product means an average diameter of a round bar portion except the knots and ribs of the steel bar for concrete reinforcement. Then, as shown in Figure 2, the material feed rate S is aligned with a rotational speed of the rollers?, R2 on the circumferential surface, but a corner a. in the roll gauge 3 as an opening of the bottom wall 1 has a small radius of rotation, and the rotational speed in the corner a. It is less than the forward speed of the material S. Therefore, since an excessive force is exerted on the corner a. and tends to cause cracking while it is being laminated, a crack can be suppressed by defining the shape of the bottom groove 1 as previously described. When it was actually exarc.a? C if a crack was caused in the corner a. of the roller varying the angle? and the slot width b. , a result was obtained as shown in the graph of Figure 3 in the case of setting the depth of the bottom groove 1 to 10% of the average diameter of the product which is an upper limit according to the standards of JIS. From the graph, you can see that the depth of the bottom groove 1 is 10% of the average diameter of the product, does not cause any roll crack if the angle? it is 10 ° or more, and the slot width b_ is 4% or more of the average diameter of the product. Further, since the crack of the roller is suppressed as the depth for the bottom groove l is smaller, the roller crack is not caused either in the case where the depth of the bottom groove 1 is 10%. or less for the average diameter of the product, provided that the angle? be 10 ° or more and the groove width b. be 4% more for the average diameter of the product. The crack of the roller is suppressed as the width h of the bottom groove 1 is greater and the angle? is greater, and the upper limit values of these are determined by the product standards defined in accordance with JIS or similar. The present invention further provides a roll for rolling a steel bar for concrete reinforcement, having a roll gauge with a substantially semi-circular transverse forca formed completely in a circumferential direction on a circumferential roller surface, round gauges formed for the purpose of crossing the roll gauge onto the surface of the roll gauge, and a bottom groove having a substantially trapezoidal cross-section and having an opening width greater than the bottom width, and formed completely over the circumferential direction to a portion central in the direction of the gauge width of the rolling gauge. The roll for laminating the steel bar for concrete reinforcement is preferably arranged so that the bottom surface of the bottom groove and the bottom surface of the round gauge are aligned, and the round gauges and the roll gauge are perpendicular. The roller for laminating the steel bar for concrete reinforcement is also preferably adapted so that the depth of the bottom groove is 10% or less of the average diameter of the product, the bottom groove has a trapezoidal transversal shape substantially isosceles, the angle made between its two non-parallel sides is 10 ° or more, and the bottom width of the bottom groove is 4% or more of the average diameter.

BRIEF EXPLANATION OF THE DRAWINGS Figure 1 is a view illustrating a preferred roller of a two-roll mill for final finishing, wherein (a) is a developed view of a roller circumferential surface and (b) corresponds to a cross-sectional view taken along line DD in (a). Figure 2 is a front elevational view illustrating a roller arrangement of a two-roll rolling mill for final finishing to realize a preferred method of the present invention. Figure 3 is a graph to explain the operation of the present invention. Figure 4 is a front elevational view illustrating a roller passing a two roll mill for final compliance in a manner according to the present invention. Figure 5 illustrates a state in a feed roller for a steel bar for concrete reinforcement obtained through a preferred embodiment according to the present invention in which (a) - (c) represent different states, respectively. Figure 6 is a view illustrating an example of an existing steel bar for concrete reinforcement where (a) is a side elevation view, and (b) corresponds to a cross-sectional view taken along the line XX of it. Figure 7 is a schematic view illustrating a roller arrangement in a two-roll mill for final finishing to obtain a steel bar for a concrete reinforcement shown in Figure 6. Figure 8 is a developed view (a) illustrating the roller of Figure 7 and a cross-sectional view (b) taken along line YY thereof. Figure 9 is a view illustrating a roller of a roller or a roller roller for the finished finish used in an existing steel bar for the concrete reinforcement laminate, where (a) is a developed view of a roller circumferential surface and (b) corresponds to a cross-sectional view taken along the line ZZ in (a).

BEST MODE FOR PRACTICING THE INVENTION To explain the present invention in more detail, a mode according to the accompanying drawings will now be explained.

Figure 1 is a view illustrating a roll of a two roll mill for final finishing used in this embodiment, wherein (a) is a developed view for a circumferential roller surface and (b) corresponds to a view in cross section along line DD in (a). In addition, Figure 4 is a front elevational view illustrating a roll pitch of a two roll mill for the final finish formed by the roll in Figure 1. As shown in Figure 1, the roller Rj ( R2) has a roller gauge 3 of substantially transverse semicircular shape formed over the entire circumferential direction in a circumferential roller surface. In addition, the round gauges 2, each of which are of predetermined width, are taxed on the roll gauge 3, in order to cross the center line LQ in the direction of the caliber width of the roll gauge 3. Round gauges 2 each is formed at an equal distance along the circumferential direction of the roll gauge 3 (ie, the center line LQ in the direction of gauge width). In addition, a bottom groove 1 having a substantially isosceles trapezoidal transverse shape and having an opening width greater than the bottom width, is formed in the central portion in the gauge width direction of the roll gauge 3 over the entire circumferential direction . As shown in Figure 4, the bottom surface of the bottom groove 1 is aligned with the bottom surface of the round bore 2. In addition, the depth c for the bottom groove 1 and round bore 2 is 0.85 mm , the diameter of the pitch (average diameter of the product) A2 is 15.9 mm, the angle is made between the two non-parallel sides of the isosceles trapezoid constituting the cross section of the bottom groove 1 is 60 °, and the bottom width b of the bottom groove 1 is 2.0 mm. Furthermore, an inclined portion 3a is formed towards a limiting portion of the circumferential surface of the rollers R] _, R3, relative to the roll gauge 3. The roller distance d is set at 2.0 mm, and the angle made between the inclined portions 3a of both rollers R] _ and R2 is fixed at 60 °. The depth c of the bottom groove 1 corresponds to 5.3% of the average diameter A2 of the product, while the width of the groove b in the bottom of the bottom groove 1 corresponds to 13% of the average diameter A2 of the product, respectively. The two-roll mill was installed as a final finishing roll, and a round bar material laminated to a predetermined external diametral size through a row of ordinary two-roll mills was placed for the finishing laminate. In this case, as shown in Figure 2 described above, a roll gap of a roller mill disposed just before the final finishing rolling mill was adjusted so that the width Hi of the ribs 4a, 4b formed by the material S filled and flowing out of the finishing rolling mill is aligned with the diameter A ^ of the circle in cross section of the round gauge 2. As a result, a steel bar for concrete reinforcement where 4 ribs were formed in the direction circumferentially substantially at an equal distance, the outer circumferential surface of all the ribs was aligned with the outer circumferential surface of the knot and the knots were formed perpendicular to the ribs, was obtained without any problem of crack in the roller. Accordingly, when the steel bar thus obtained for concrete reinforcement 5 is rotated, as shown in Figure 5 (a) - (c), on a feed roll 6 as a feed device for a manufacturing machine At least one rib 4 is pre-opposed against each groove surface 6a of the feed roller 6. Therefore, the bar for the concrete reinforcement is fed accurately, while it is safely supported on the feed roller. 6. Furthermore, since the knots 12 are perpendicular to the rib 4, there is also the merit that twisting does not occur after bending production. Also, in the modality described above, since the depth c. from the bottom groove 1 is made at 5.3% of the average diameter A2 of the product and the width of the groove b at the bottom of the bottom groove 1 is made at 13% of the average diameter A2 of the product, a steel bar for reinforcement of concrete 5 having 4 ribs, was obtained stably without any occurrence of roller cracking problem.

INDUSTRIAL APPLICABILITY As described above, in the method of the present invention, a steel bar for reinforcing co-concrete provided with knots and four ribs can be obtained stably by performing the final finishing laminate through a two-roll mill. This makes it possible to obtain a steel bar for concrete reinforcement with four ribs by applying a rolling installation to produce an existing two-rib steel bar for concrete reinforcement by first changing the roll of the two-roll mill for final finishing. Accordingly, the method and the roller according to the present invention can be suitably used as a method to produce a steel bar for concrete reinforcement by having four ribs at a reduced cost and using a roller thereof.

Claims (6)

1. A method for laminating a steel bar for concrete reinforcement to form knots and ribs on the circumferential surface of a material supplied by an ir.cli or final finishing laminate of a lamination system with continuous heat, wherein a plurality of two roller mills are arranged in series, wherein the final finishing laminate is made through a pair of two rollers having a roller gauge having a substantially semicircular transverse shape formed completely in a circumferential direction on a circumferential surface of the roll, round gauges formed in order to cross the roll gauge on the surface of the roll gauge, and a bottom groove having a substantially trapezoidal cross shape and having an aperture width greater than a bottom width, and formed completely on the circumferential direction towards a central portion in the direction of to gauge width of the roll gauge, thus forming four ribs through the metal that fills the gap between the rolls and the metal flowing into the bottom groove

2. A method for laminating a steel bar for concrete reinforcement as defined in claim 1, wherein the roller is arranged so that the bottom surface of the bottom groove (1) and the bottom surface of the round gauge ( 2) are aligned, the round calibers and the roll gauge (3) are arranged perpendicular, and the sheet or is made fixing conditions so that the width (H? _) Between the ribs (4a, 4b) formed by the Metal filler and metal flow is aligned with or substantially aligned with the diameter. { A-, of a circle in cross section of the round caliber.

3. A method for laminating a steel bar for concrete reinforcement as defined in claim 2, wherein the roller is adapted so that the depth of the bottom groove is 10% or less of the average diameter of the product, the groove bottom has a substantially isosceles trapezoidal cross-sectional shape and an angle (?) made between the two non-parallel sides thereof and that is 10 ° or more, and the bottom width (b) of the bottom slot is 4% or more of the average diameter.

4. A steel rod for rolling concrete reinforcement of rolling roll qe has a roll gauge having a cross-sectional shape substantially semicircular over the entire circumferential direction a circumferential surface of the roll, round gauges disposed to the surface of the roll gauges in order to cross the roll gauge, and a bottom groove having a substantially trapezoidal cross-sectional shape and having an opening width greater than the bottom width disposed over the entire circumferential direction towards a central portion in the direction of the gauge width of roll gauge.

5. A rolling roll for a steel bar for concrete reinforcement is defined in claim 4, wherein the bottom surface the bottom groove and the bottom surface of the round gauge are aligned and the round gauges and the roll gauge are arranged in order to be perpendicular

6. A rolling roll for a steel bar for concrete reinforcement as defined in claim 5, wherein the depth groove depth is 10% or less of the average diameter of a product, the bottom groove has In a trapezoidal and substantially isosceles transverse form, the angle made between the two non-parallel sides thereof is 1CC c plus, and the bottom width of the bottom groove is 4% or more of the average diameter.