Guide roll for rolling apparatus

Abstract

To provide a guide roll 6 that does not need to be replaced frequently.SOLUTION: A guide device comprises a plurality of guide rolls 6 arranged at an equal pitch angle around a center of a passing intermediate long steel product. Each guide roll 6 includes a guide groove 8 extending in a circumferential direction. In a cross section taken along a plane including an axis of the guide roll 6, the guide groove 8 includes a first straight zone 14a and a second straight zone 14b. Preferably, an angle formed between the first straight zone 14a and the second straight zone 14b is 120° to 140°, inclusive.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present specification relates to a rolling mill suitable for producing long steel products. In particular, the present specification discloses guide rolls that guide intermediate long steel products into a rolling mill. [Background technology]

[0002] Long steel can be obtained by continuous rolling. In a typical continuous rolling process, a steel billet is subjected to rough rolling, intermediate rolling, and finishing rolling. During these rolling processes, the intermediate long steel product is gradually reduced in diameter and length.

[0003] In the finishing train rolling, a plurality of multi-roll rolling mills are used. A guide device is arranged upstream of each rolling mill. This guide device has a plurality of guide rolls. Each guide roll has a guide groove. The shape of the portion of the outline of the intermediate long steel product that contacts the guide groove is generally an arc. Therefore, the cross-sectional shape of the guide groove is also a curve. An example of a guide roll is disclosed in JP 2003-001318 A. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-001318 A Summary of the Invention [Problem to be solved by the invention]

[0005] In factories, long steel bars of various sizes are produced. Therefore, intermediate long steel products of various sizes pass through the rolling mill. In the rolling mill, the rolling rolls are replaced with rolls of a size suitable for the size of the intermediate products. Along with this replacement, the guide rolls are also replaced. Frequent replacement of the guide rolls impedes the productivity of long steel bars.

[0006] The applicant's intention is to provide a guide roll that requires less frequent replacement. [Means for solving the problem]

[0007] The multi-roll guide device disclosed in this specification has a plurality of guide rolls arranged at equal pitch angles around the center of a passing intermediate long steel product. Each guide roll has a guide groove extending in the circumferential direction. In a cross section taken along a plane including the axis of the guide roll, this guide groove has a pair of straight zones for holding the intermediate long steel product.

[0008] Preferably, the angle formed between one straight zone and the other straight zone is equal to or greater than 120° and equal to or less than 140°. Preferably, the number of guide rolls is three.

[0009] The guide roll disclosed herein has a guide groove extending in the circumferential direction. In a cross section taken along a plane including the axis of the guide roll, the guide groove has a pair of straight zones. Preferably, the angle between one straight zone and the other straight zone is 120° or more and 140° or less.

[0010] The method for producing long steel bars disclosed in the present specification includes: A: A process for obtaining intermediate products of long steel. B: A process of guiding this intermediate long steel product to a rolling mill using a multi-roll guide device. and C: A process of rolling the intermediate long steel product using the rolling mill. The guide device used in this process B has a plurality of guide rolls arranged at equal pitch angles around the passing intermediate long steel product. Each guide roll has a guide groove extending in the circumferential direction. In a cross section taken along a plane including the axis of the guide roll, the guide groove has a pair of straight zones for holding the intermediate long steel product.

[0011] Preferably, in step B, the intermediate long steel product is guided by a guide device having guide rolls in which the angle formed between one straight zone and the other straight zone is 120° or more and 140° or less.

[0012] Preferably, in step B, a guide device having three guide rolls guides the intermediate long steel product.

[0013] Preferably, in process B, the intermediate long steel product is guided by a guide device having guide rolls in which the ratio (L1 / L2) of the distance L1 from the contact point Pt between the straight zone and the intermediate long steel product to the inner end P1 of the straight zone to the distance L2 from this contact point Pt to the outer end P2 of the straight zone is 1.8 / 1.2 or more and 2.2 / 0.8 or less. [Effects of the Invention]

[0014] This guide roll is highly versatile, and a method for manufacturing a bar using this guide roll is highly productive. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a front view showing a guide device according to one embodiment together with a bar intermediate product. [Figure 2] FIG. 2 is a perspective view showing a guide roll of the guide device of FIG. [Figure 3] FIG. 3 is a front view showing the guide roll of FIG. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a portion of the guide roll of FIG. [Figure 5] FIG. 5 is a cross-sectional view showing the guide roll of FIG. 4 together with a part of the intermediate long steel product. [Figure 6] FIG. 6 is a flowchart showing an example of a method for manufacturing a bar in which the guide device of FIG. 1 is used. [Figure 7] FIG. 7 is a flowchart showing an example of the continuous rolling process of the method of manufacturing bar steel in FIG. [Figure 8] FIG. 8 is a block diagram showing an apparatus for finishing row rolling in the continuous rolling process of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, preferred embodiments will be described in detail with reference to the drawings as appropriate.

[0017] FIG. 1 shows a guide device 4 together with an intermediate long steel product 2. The intermediate long steel product 2 is rolled in a rolling mill upstream of this guide device 4. This rolling mill has a plurality of rolls, each of which has a caliber. The intermediate long steel product 2, whose shape reflects the shape of the caliber, reaches the guide device 4.

[0018] The guide device 4 has a first guide roll 6a, a second guide roll 6b, and a third guide roll 6c. The number of guide rolls 6 is three. These guide rolls 6 are arranged at equal pitch angles around the intermediate long product 2. In this embodiment, these guide rolls 6 are arranged at a pitch of 120°. Each guide roll 6 rotates around a shaft (not shown). The specifications of the second guide roll 6b are the same as those of the first guide roll 6a, except for the direction of rotation. The specifications of the third guide roll 6c are the same as those of the first guide roll 6a, except for the direction of rotation. The number of guide rolls 6 in the guide device 4 may be four.

[0019] 2 and 3 show the guide roll 6. The guide roll 6 has a guide groove 8. The guide groove 8 extends along the circumferential direction of the guide roll 6. The guide groove 8 is located at the center of the guide roll 6 in the axial direction. The guide roll 6 also has a pair of shaft holes 10. A shaft is inserted into each hole 10. The guide roll 6 has a shape that is mirror-symmetrical in the axial direction.

[0020] FIG. 4 shows a cross section of the guide roll 6 taken along a plane including the axis. In this cross section, the guide groove 8 has a central zone 12, a first straight zone 14a, and a second straight zone 14b. The cross-sectional shape of the central zone 12 is a curve. In this embodiment, the shape of the central zone 12 is an arc. The cross-sectional shape of the first straight zone 14a is a straight line. The cross-sectional shape of the second straight zone 14b is a straight line. In this embodiment, the second straight zone 14b is mirror-symmetrical to the first straight zone 14a. In FIG. 4, symbol P1 denotes the inner end of the straight zone 14, and symbol P2 denotes the outer end of the straight zone 14. The inner end P1 is also the boundary between the straight zone 14 and the central zone 12.

[0021] Figure 5 shows the guide rolls 6 and the intermediate long steel product 2. The intermediate long steel product 2 is held in the guide groove 8. Because the cross-sectional shape of each straight zone 14 (see Figure 4) is straight, the intermediate long steel product 2 comes into contact with this straight zone 14. The straight zone 14 comes into point contact with the intermediate long steel product 2. In Figure 6, the symbol Pt denotes the point of contact between the straight zone 14 and the intermediate long steel product 2. Because the guide groove 8 has two straight zones 14, the guide rolls 6 hold the intermediate long steel product 2 at the two points of contact Pt.

[0022] Since the number of guide rolls 6 is three, the intermediate long steel product 2 is held in the guide device 4 at the contact point Pt of 6. This holding suppresses twisting of the intermediate long steel product 2. Rolling using this guide device 4 can produce long steel with excellent dimensional accuracy.

[0023] Since the straight zone 14 comes into point contact with the long steel intermediate product 2, the guide rolls 6 can also hold other long steel intermediate products 2 having sizes different from the size of the long steel intermediate product 2 shown in FIG. 5. The guide rolls 6 can guide a plurality of types of long steel intermediate products 2 having different sizes. In a long steel plant, after a first long steel product is produced, the rolling rolls are replaced before a second long steel product having a size different from the first long steel product is produced. In this case, the second long steel product can be produced without replacing the guide rolls 6. The guide rolls 6 do not need to be replaced frequently. The guide rolls 6 are highly versatile. The guide rolls 6 can contribute to the productivity of long steel products.

[0024] In Figure 4, the arrow θ indicates the angle between the first straight zone 14a and the second straight zone 14b. The angle θ is preferably 120° or greater and 140° or less. A guide roll 6 with an angle θ of 120° or greater has excellent versatility. From this perspective, the angle θ is particularly preferably 125° or greater. A guide roll 6 with an angle θ of 140° or less can produce bar steel with excellent dimensional accuracy. From this perspective, the angle θ is particularly preferably 135° or less.

[0025] The ratio (L1 / L2) of the distance L1 from the contact point Pt to the inner end P1 to the distance L2 from this contact point Pt to the outer end P2 is preferably 1.8 / 1.2 or more and 2.2 / 0.8 or less. A rolling mill having a ratio (L1 / L2) within this range can produce bar steel with excellent dimensional accuracy. From this perspective, the ratio (L1 / L2) is particularly preferably 1.9 / 1.1 or more and 2.1 / 0.9 or less.

[0026] FIG. 6 shows a flowchart of an example of a method for manufacturing long steel. In this manufacturing method, a steel slab is obtained through refining (STEP 1), ingot making (STEP 2), and blooming (STEP 3). The steel slab is heated in a heating furnace (STEP 4). The steel slab is subjected to continuous hot rolling (STEP 5). In this continuous rolling, a long steel intermediate product 2 is obtained from the steel slab, and this long steel intermediate product 2 is gradually reduced in diameter and length. This long steel intermediate product 2 is cut to a predetermined length (STEP 6). After cutting, the long steel intermediate product 2 is subjected to processes such as heat treatment, straightening, and inspection as necessary to obtain long steel. Examples of long steel include steel bars and steel wires.

[0027] A flowchart of an example of continuous rolling (STEP 5) is shown in Figure 7. In this continuous rolling (STEP 5), rough row rolling (STEP 5.1), intermediate row rolling (STEP 5.2), and finish row rolling (STEP 5.3) are performed.

[0028] FIG. 8 shows an apparatus 16 for finishing train rolling (STEP 5.3). This apparatus 16 includes a first stand 18a, a second stand 18b, a third stand 18c, a fourth stand 18d, and a fifth stand 18e. The first stand 18a includes a rolling mill 20a. The second stand 18b includes a guide device 4b and a rolling mill 20b. The third stand 18c includes a guide device 4c and a rolling mill 20c. The fourth stand 18d includes a guide device 4d and a rolling mill 20d. The fifth stand 18e includes a guide device 4e and a rolling mill 20e. The rolling mills 20 in each stand 18 are of a three-roll type. The rollers of these rolling mills 20 have calibers. The guide device 4 in each stand 18 includes three guide rolls 6. Each guide roll 6 has a guide groove 8 having the shape shown in FIG. 4.

[0029] The intermediate long steel product 2 that has passed through the intermediate row rolling (STEP 5.2) proceeds to the first stand 18a. The intermediate long steel product 2 is rolled by the rolling mill 20a of this first stand 18a (STEP 5.3.1).

[0030] The intermediate long product 2 proceeds to the second stand 18b. The guide grooves 8 of the guide rolls 6 in the second stand 18b have a shape corresponding to the caliber of the rolling rolls in the first stand 18a. The intermediate long product 2 is guided to the rolling mill 20b by the guide device 4b of the second stand 18b (STEP 5.3.2). The intermediate long product 2 is rolled by the rolling mill 20b (STEP 5.3.3).

[0031] The intermediate long product 2 proceeds to the third stand 18c. The guide grooves 8 of the guide rolls 6 in the third stand 18c have a shape corresponding to the caliber of the rolling rolls in the second stand 18b. The intermediate long product 2 is guided to the rolling mill 20c by the guide device 4c of the third stand 18c (STEP 5.3.4). The intermediate long product 2 is rolled by the rolling mill 20c (STEP 5.3.5).

[0032] The intermediate long product 2 proceeds to the fourth stand 18d. The guide grooves 8 of the guide rolls 6 in the fourth stand 18d have a shape corresponding to the caliber of the rolling rolls in the third stand 18c. The intermediate long product 2 is guided to the rolling mill 20d by the guide device 4d of the fourth stand 18d (STEP 5.3.6). The intermediate long product 2 is rolled by the rolling mill 20d (STEP 5.3.7).

[0033] The intermediate long product 2 proceeds to the fifth stand 18e. The guide grooves 8 of the guide rolls 6 in the fifth stand 18e have a shape corresponding to the caliber of the rolling rolls in the fourth stand 18d. The intermediate long product 2 is guided to the rolling mill 20e by the guide device 4e of the fifth stand 18e (STEP 5.3.8). The intermediate long product 2 is rolled by the rolling mill 20e (STEP 5.3.9).

[0034] In each stand 18, the guide device 4 can securely hold the intermediate long steel product 2. Even when another intermediate long steel product 2 having a size slightly different from that of the intermediate long steel product 2 is passed through the device 16 in Fig. 8, there is no need to replace each guide roll 6. [Industrial Applicability]

[0035] The guide rolls described above are suitable for guiding a variety of metal products. [Explanation of symbols]

[0036] 2. Intermediate long steel products 4. Guide device 6 Guide roll 6a···First guide roll 6b Second guide roll 6c···Third guide roll 8 Guide groove 10. Shaft hole 12. Central Zone 14. Straight Zone 14a First Straight Zone 14b Second Straight Zone 18···Stand 18a First Stand 18b...Second stand 18c···Third Stand 18d···Fourth Stand 18e···Fifth Stand 20. Rolling mill

Claims

1. It has multiple guide rolls arranged at equal pitch angles around the intermediate steel bar passing through it. Each guide roll has a guide groove extending in the circumferential direction, A multi-roll guide device, wherein the guide groove has a pair of straight zones for holding the intermediate long steel product in a cross section taken along a plane including the axis of the guide roll.

2. 2. The guide device according to claim 1, wherein an angle formed between one straight zone and the other straight zone is equal to or greater than 120 degrees and equal to or less than 140 degrees.

3. 3. The guide device according to claim 1, wherein the number of guide rolls is three.

4. It has a guide groove extending in the circumferential direction, A guide roll, wherein the guide groove has a pair of straight zones in a cross section taken along a plane including the axis.

5. 5. The guide roll according to claim 4, wherein an angle formed between one straight zone and the other straight zone is 120° or more and 140° or less.

6. A: A process for obtaining a long steel intermediate product; B: A step of guiding the intermediate long steel product to a rolling mill using a multi-roll guide device; and C: A step of rolling the intermediate steel bar product using the rolling mill It is equipped with A method for manufacturing long steel bars, wherein the guide device used in the above-mentioned process B has a plurality of guide rolls arranged at equal pitch angles around the passing long steel intermediate product, each guide roll having a guide groove extending circumferentially, and in a cross section along a plane including the axis of the guide roll, the guide groove has a pair of straight zones for holding the long steel intermediate product.

7. 7. The manufacturing method according to claim 6, wherein in step B, the intermediate long steel product is guided by a guide device having guide rolls in which the angle formed between one straight zone and the other straight zone is 120° or more and 140° or less.

8. 8. The manufacturing method according to claim 6, wherein in step B, a guide device having three guide rolls guides the intermediate long steel product.

9. 8. A manufacturing method according to claim 6 or 7, wherein in step B, the intermediate section steel product is guided by a guide device having guide rolls in which the ratio (L1 / L2) of the distance L1 from the contact point Pt between the straight zone and the intermediate section steel product to the inner end P1 of the straight zone to the distance L2 from the contact point Pt to the outer end P2 of the straight zone is 1.8 / 1.2 or more and 2.2 / 0.8 or less.

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