KR19990063724A - Rolling method of deformed bar and roll for deformed bar - Google Patents

Abstract

By performing the final finishing rolling with a two-roller rolling, a release bar with a bar 12 and four ribs 4 is obtained.

The rolls R ₁ and R ₂ used in the two-roller for final finishing have a circumferential groove 3, a node groove 2, and a bottom groove 1.

The circumferential groove 3 has a semicircular cross section and is formed over the entire circumferential direction on the roll circumferential surface.

The nodular groove 2 is formed in the groove surface of the circumferential groove 3 with a predetermined width so as to intersect the circumferential groove 3.

The bottom groove 1 has an equilateral trapezoidal cross section and is formed over the entire circumferential direction at the center portion of the groove width direction of the circumferential groove 3.

Description

Rolling method of deformed bar and roll for deformed bar

A general thing as a conventional release bar is shown in FIG.

In FIG. 6, (a) is a side view and (b) is sectional drawing along the X-X line of (a).

In this release bar 5, a plurality of convex portions (nodes) 12 are formed on the circumferential surface of the round rod material at substantially equal intervals in the longitudinal direction.

In addition, two convex portions (ribs) 4 are formed in positions along the longitudinal direction at positions 180 degrees apart in the circumferential direction of the circle.

Such a deformed bar 5 is a final finishing mill of a hot rolling mill in which a plurality of two-roller rolling mills are arranged in series to finish finishing rolls R ₁ and R ₂ as shown in FIGS. 7 and 8. It is manufactured by rolling.

Fig. 7 is a front view showing the arrangement of both finishing rolls, Fig. 8A is a development view of the roll circumferential surface, and Fig. 8B is a sectional view taken along the line Y-Y in Fig. 7A.

As can be seen from these figures, the semi-circular circumferential grooves 3 of which the cross section is substantially semicircular over the entire circumferential direction are formed in both of the finishing rolls R ₁ and R ₂ forming the hole molds for the final finishing. .

Moreover, the groove surface 2 of the circumferential groove 3 is provided with the node groove 2 which intersects this circumferential groove 3 at right angles.

And the grooves on the circumferential surface of the round rod material by passing the material (S) whose cross section is rolled in an ellipse by the upstream rolling column through the hole mold formed by the finishing rolls R ₁ and R ₂ . ), the ribs (4) produced by asking a clearance from the joint 12 and the material (S) between the roll _{(R 1), (R 2} ) is formed according to the.

Moreover, the node of a mold release bar may be arrange | positioned inclined with respect to the longitudinal direction.

In this case, as shown in Fig. 9, the nodular groove 2 of the finishing roll R is inclined by a predetermined angle α with respect to the circumferential direction.

In FIG. 9, (a) is a development view of the circumferential surface of the finishing roll R, (b) is sectional drawing along the Z-Z line.

Also in this case, there are only two ribs of the mold release bar obtained by pinching from the finishing rolls (R).

In recent years, such a deformed bar is bent by a processing machine.

In this case, if there are only two ribs, it is difficult to stably support the surface of the deformed bar by the feeding device or the supporting device of the processing machine.

Therefore, a release bar having four ribs at substantially equal intervals in the circumferential direction is required.

In addition, the release bar is used as a reinforcing steel for reinforcement concrete, but there are advantages in that the four ribs increase the adhesion to concrete.

However, a technique for producing a release bar having four ribs has not been established.

For example, according to a technique previously filed by the present applicant (see Japanese Patent Application Laid-Open No. 7-323302), it is possible to manufacture a four-bar deformed bar by using four roll mills in the final finishing mill, but the cost Is higher.

In addition, it is not practical to form four ribs by performing final finishing rolling with a two-roller rolling mill.

SUMMARY OF THE INVENTION The present invention has been made in view of such a point, and an object of the present invention is to obtain a deformed bar having a node and four ribs by performing a final finish rolling in a two-roller rolling mill.

The present invention relates to a rolling method for obtaining a deformed bar used in rebar, etc., wherein the deformed bar having four ribs extending in the longitudinal direction can be stably obtained by a two-roller mill. A method, and a roll used in the method.

1 is a roll of a two-roller for a preferred final finishing according to the present invention

It is a drawing to show,

(a) is an exploded view of a roll circumferential surface, (b) is sectional drawing along the D-D line of (a).

Figure 2 is a front view showing the roll arrangement of the two-roller rolling mill for the final finishing in which the preferred method of the present invention is carried out.

Figure 3 is a graph for explaining the operation of the present invention

Fig. 4 shows a two-roller rolling mill for final finishing in one embodiment of the present invention.

Front view showing roll hole mold

Fig. 5 shows the feed bar of the release bar obtained in one embodiment of the present invention.

(A) to (c) are diagrams showing different states.

6 is a view showing an example of a conventional release bar,

(a) is a side view, (b) is sectional drawing along the X-X ray.

7 is a two-roller rolling mill for the final finishing to obtain the deformed bar of FIG.

Schematic diagram showing roll placement

FIG. 8 is a development (a) showing the roll of FIG. 7 and a cross-sectional view (b) along the Y-Y line thereof.

Fig. 9 is a view showing a roll of a two-roller rolling mill for final finishing used in conventional rolled rod rolling;

(a) is an exploded view of the roll circumferential surface, (b) is a cross-sectional view taken along the Z-Z line of (a)

(Explanation of symbols for main parts of drawing)

1. Bottom groove

2. Groove

3. Wonju Home

4. Rib

12. Node

A ₁ .The diameter of the section circle

A ₂ . Average diameter of the product

b. Bottom width of bottom groove

c. Depth of bottom groove

H ₁ .rib width

The rolling method of the rolled bar of the present invention is a rolled bar of the rolled bar in which a roll and a rib are formed on the circumferential surface of the material which is sent out by the final finishing mill of a hot rolling mill having a plurality of roll mills arranged in series. The cross-section formed on the roll circumferential surface over the entire circumferential direction has a semi-circular circumferential groove, a nod groove formed on the circumferential groove so as to intersect the circumferential groove, and a cross section formed over the entire circumferential direction at the center of the groove width direction of the circumferential groove. It is characterized in that the final finishing rolling is performed by two pairs of two rolls having a bottom groove having an opening width larger than that of the bottom portion in a substantially trapezoidal shape, and four ribs are formed by pitting from the roller gap and the bottom groove. have.

According to this method, two ribs are formed by the bottom groove formed in each roll in addition to the two ribs formed by the burrow from the roll.

Since the rib by the bottom groove is formed in the center portion in the groove width direction of the circumferential groove, a release bar in which four ribs are formed at equal intervals or almost equal intervals in the circumferential direction is obtained.

For example, as shown in Fig. 1, the roll includes the bottom of the bottom groove 1 and the bottom of the nodular groove 2, and the nodular groove 2 and the circumferential groove 3 intersect at right angles. As shown in Fig. 2, the width H ₁ between the ribs 4a and 4b by pinching coincides or almost coincides with the diameter A ₁ of the cross-sectional circle of the nodular groove 2. It is preferable to set conditions so that rolling may be performed.

According to this method, in addition to forming four ribs at equal or nearly equal intervals in the circumferential direction, the outer circumferential surface of all ribs coincides or nearly coincides with the outer circumferential surface of the node, and the node is formed perpendicular to the rib. do.

In addition, as shown in Fig. 2, the depth of the bottom groove 1 is 10% or less of the average diameter of the product, and the bottom groove 1 has an angle formed by two sides that are substantially equilateral trapezoidal in cross section and not parallel to each other. Is 10 degrees or more and the bottom portion width b of the bottom groove 1 is preferably 4% or more of the above average diameter.

Incidentally, the substantially trapezoidal shape and the substantially equilateral trapezoidal shape represent a shape in which two parallel sides of the trapezoid (not including parallel quadrilaterals) and the equilateral trapezoid are strictly not straight lines but are concentric circular arcs.

And the short side of these circular arcs forms the bottom face of a bottom groove, and the long side forms an opening part. In addition, the average diameter of the above-mentioned product means the average diameter of the round bar part except the node and the rib of a release bar.

Here, as shown in FIG. 2, the traveling speed of the raw material S coincides with the rotational speed on the circumferential surfaces of the rolls R ₁ and R ₂ , but is a circumferential groove 3 that is an opening of the bottom groove 1. The corner portion a of the () has a small radius of rotation, and the rotational speed of the corner portion a is later than the advancing speed of the raw material S.

Therefore, the corner portion a is easily broken due to excessive force during rolling, but can be difficult to be broken by limiting the shape of the bottom groove 1 as described above.

The depth of the bottom groove 1 is determined by varying the angle θ and the groove width b so as to determine whether cracks occur in the corners a of the roll. The depth of the bottom groove 1 is the upper limit of the Japanese Industrial Standard (JIS) standard. At 10%, the result was as shown in the graph of FIG.

From this graph, when the depth of the bottom groove 1 is 10% of the average product diameter, the angle θ is 10 ° or more, and when the groove width b is 4% or more of the product average diameter, no breakage of the roll occurs. I knew that.

In addition, since the depth of the bottom groove 1 is less likely to be cracked in the roll, even when the depth of the bottom groove 1 is less than 10% of the average product diameter, the angle θ is 10 ° or more and the groove width b ) Is 4% or more of the average diameter of the product so that no breakage of the roll occurs.

In addition, although the groove width b of the bottom groove 1 is wider and the angle θ is larger, the roller becomes more fragile, but these upper limits are set according to product standards determined by Japanese Industrial Standards.

The present invention further includes a semicircular circumferential groove formed on the roll circumferential surface over the entire circumferential direction, and a nod groove formed so as to intersect the circumferential groove on the circumferential groove and the circumferential direction of the circumferential groove throughout the circumferential direction. Provided is a rolled roll for rolling a rolled bar having a bottom groove having a wider opening portion width than the bottom portion width in a substantially trapezoidal shape.

It is preferable that the release bar rolling roll is disposed such that the bottom of the bottom groove and the bottom of the nodular groove coincide with each other and the nodular groove and the circumferential groove cross at right angles.

In the rolled roll for rolled rolled bar, the depth of the bottom groove is less than 10% of the average diameter of the product, and the bottom groove has an approximately equilateral trapezoidal shape with an angle of 10 ° or more between two non-parallel cross sections. It is preferable that the bottom part width is 4% or more of the average diameter.

EMBODIMENT OF THE INVENTION Hereinafter, in order to demonstrate this invention in detail, one Embodiment is attached according to attached drawing.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the roll of the 2 roll mill for final finishing used in this embodiment, (a) is a development view of a roll peripheral surface, (b) is corresponded to sectional drawing along the D-D line of (a).

Fig. 4 is a front view showing the roll hole mold of the final roll forming roll mill formed by the roll of Fig. 1 in this embodiment of the present invention.

Roll (R _1), (R ₂₎ As shown in Figure 1 has a substantially semi-circular circumferential groove 3 on the end surface is formed over the entire circumferential direction on the roll circumferential surface.

Further, the groove 3 of the predetermined width is formed in the circumferential groove 3 so as to cross at a right angle with the groove width direction center line L ₀ of the circumferential groove 3.

The nodular grooves 2 are formed at equal intervals along the circumferential direction of the circumferential groove 3 (ie, the groove width direction center line L ₀ ).

Moreover, the bottom groove 1 of which the opening part width | variety is larger than a bottom part width part is formed in the groove width direction center part of the circumferential groove 3 in an approximately equilateral trapezoidal shape in the whole circumferential direction.

As shown in FIG. 4, the bottom of the bottom groove 1 coincides with the bottom of the node groove 2.

In addition, the depth (c) of the bottom groove (1) and the node groove (2) is 0.85mm, the diameter of the hole mold (average diameter of the product) (A ₂ ) is 15.9mm, isometric to form a cross section of the bottom groove (1) The angle θ formed by two non-parallel parallel sides is 2.0 mm at the bottom width b of the 60 ° bottom groove 1.

Incidentally, the inclined portion 3a is formed at the boundary portion with the circumferential groove 3 of the circumferential surfaces of the rolls R ₁ and R ₂ .

The roll spacing d was 2.0 mm, and the angle β between the inclined portions 3a of both the rolls R ₁ and R ₂ was set to 60 °.

Here, the depth (c) of the bottom groove (1) is 5.3% of the average diameter (A ₂ ) of the product, the groove width (b) of the bottom side of the bottom groove (1) is 13% of the average diameter (A ₂ ) of the product Each corresponds to

Such a two-roller rolling mill was installed as a final finishing mill, and the rolled round bar material was rolled to a predetermined outer diameter in a normal two-roller rolling mill.

At that time, as shown in Fig. 2, the width H ₁ of the ribs 4a and 4b by squeezing out the raw material S exiting the final finishing mill is the diameter A of the cross-section circle of the nodular groove 2. _The roller spacing of the rolling mill arrange | positioned immediately before final finishing rolling mill was adjusted so that it might correspond to ₁ ).

As a result, a deformed bar was obtained in which no rib breakage occurred and four ribs were formed at substantially equal intervals in the circumferential direction, the outer circumferential surfaces of all the ribs coincided with the outer circumferential surfaces of the nodes, and the nodes were formed at right angles to the ribs.

Therefore, even if the obtained release bar 5 rotates in the feed roller 6 which is a feeder of a processing machine, as shown to FIG. 5 (a)-(c), each groove surface of the feed roller 6 ( At least one rib 4 is always in contact with 6a). Therefore, the release bar 5 is firmly supported by the feed roller 6, and is sent out correctly.

Moreover, since the node 12 is perpendicular to the rib 4, there is also an advantage that no distortion occurs during bending.

In the above embodiment, the depth c of the bottom groove 1 is 5.3% of the average diameter A ₂ of the product, and the groove width b of the bottom side of the bottom groove 1 is the average diameter A of the product. _{By setting it} as 13% of ₂ ), the release bar 5 which had four ribs 4 stably was obtained without causing the damage of a roll failure.

As described above, in the method of the present invention, the final finish rolling is performed by a two-roller rolling mill, whereby a release bar having a section and four ribs is stably obtained.

This makes it possible to obtain four ribs of the deformed bar by simply changing the roll of the final two-roller rolling mill using a rolling facility for producing the two-bar deformed bar. Therefore, the method and the roll of the present invention are very suitably used as a method for producing a four-bar deformed bar at low cost and a roll therefor.

Claims (6)

In a rolling method of a rolled steel bar in which a roll 12 and a rib 4 are formed on a circumferential surface of a material S sent by a final finishing mill of a hot rolling mill having a plurality of roll mills arranged in series. , The groove circumference of the circumferential groove 3 is formed on the roll circumferential surface, and the cross section formed over the entire circumferential direction has a semi-circular circumferential groove 3, and the groove on the circumferential groove surface is formed so as to intersect the circumferential groove 3 on the circumferential groove surface. End finish rolling is carried out by a pair of two rolls having a bottom groove 1 having an opening width of more than the bottom width of the cross section formed in the circumferential direction in the circumferential direction substantially in a trapezoid shape, and Rolling method of a mold release steel, characterized in that forming four ribs (4) by the bottom groove. The method of claim 1, The roll is arranged so that the bottom of the bottom groove 1 and the bottom of the nodular groove 2 coincide with each other, and the nodular groove 2 and the circumferential groove 3 intersect at right angles. Rolling method of rolling bar, characterized in that the rolling conditions are set so that the width (H ₁ ) between (4) matches or almost coincides with the diameter (A ₁ ) of the cross-section circle of the nodule groove (2). The method of claim 2, The depth of the bottom groove (1) is 10% or less of the average diameter of the product, the bottom groove (1) has an approximately equilateral trapezoidal cross section, the angle (θ) of two sides that are not parallel to each other is 10 ° or more, And the bottom portion width b of the bottom groove 1 is 4% or more of the average diameter A ₂ of the above-described product. The semicircular circumferential groove 3 having a cross section formed over the entire circumferential direction on the roll circumferential surface, the nodular groove 2 formed on the circumferential groove 3 surface to intersect the circumferential groove 3, and the above circumference. A rolled roll for rolled roll bar, characterized in that the groove width direction center portion of the groove (3) is formed in a substantially trapezoidal cross section with a bottom groove (1) whose opening portion width is larger than the bottom portion width. The method of claim 4, wherein The bottom surface of the bottom groove (1) and the bottom surface of the node grooves (2) coincide with each other, further characterized in that the node grooves (2) and the circumferential groove (3) is arranged to cross at a right angle. The method of claim 5, The depth (c) of the bottom groove (1) is less than 10% of the average diameter (A ₂ ) of the product, the bottom groove (1) has an approximately equilateral trapezoidal cross section, the angle formed by two sides that are not parallel to each other 10 ° or more And the bottom portion width of the bottom groove 1 is 4% or more of the average diameter of the product.