JPS6376702A - Rolling method and rolling roller device for round steel bar - Google Patents

Abstract

PURPOSE:To permit rolling of a round steel bar having high dimensional accuracy by disposing a rolling roller device in which 2 sets of a pair of idle rollers are housed in the perpendicular direction to the outlet side of final rolling rolls and constituting the device in such a manner that the respective rolls can be freely rotated. CONSTITUTION:The rolling roller device for correcting the shoulder part and transverse part of the round steel bar where there is the tendency to filling to the outlet side of the final rolling rolls of a continuous rolling mill. The idle rollers 11, 12 and 13, 14 which are respectively paired are pivotally supported to each other in said roller device. The shafts of the rollers 11, 12 and 13, 14 maintain 90 deg. angle and are housed on the same plane within a housing 15. The rollers 11-14 are freely turnably mounted to an eccentric sleeve 17 key-fitted to a shaft 16. The rollers 11-14 are moved in the direction orthogonal with the shaft 16; i.e, around the housing 15 by turning the eccentric sleeve 17 so as to attach and detach to and from each other. The part of the rolled round steel bar where there is the tendency to filling is corrected by such device, by which the rolling of the round steel bar having high out-of-roundness is permitted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of rolling a round steel bar and a rolling roller device used in the rolling method.

(Prior art and its problems) When manufacturing a round bar using rolling rolls, a 1ffl billet with a regular rectangular cross section is rolled several times to form an elliptical cross-sectional material 2 as shown in FIG. 3, and then a pair of circular rL Mold roll 1.
1" to obtain the circular cross-sectional material 3.Here, in the circular cross-sectional material f43, the cross-sectional dimension 11 in the direction perpendicular to the roll axis 4.4" is called the vertical dimension, and the roll axis 4
．． The cross-sectional dimension B in the 4° direction is referred to as the width dimension.

Generally, in a finished circular hole type, a clearance angle θ is provided on the flange side as shown in FIG. 4, and this range is set to a radius larger than the finished radius R, for example, 2R. The reason for providing such a relief part (hereinafter referred to as the "shoulder part") is that during actual operation, temperature fluctuations in the rolled material and changes in the tension acting on the rolled material in the rolling direction (hereinafter referred to as the "inter-stand tension") occur. This is to prevent the width dimension B from fluctuating significantly in the longitudinal direction of the rolled material and causing the width portion to bulge out.

Therefore, in order to achieve precision rolling with high roundness, it is ideal to eliminate the fluctuation factors of the width dimension B and make the clearance angle θ zero, but as will be explained later, this is extremely difficult. Have difficulty. When we examine the dimensional variations in the longitudinal direction of the vertical dimension H and the width dimension B of a circular cross-sectional material, as shown in Figure 5, the variation in the vertical dimension H is small, but the width dimension B is large, and this causes a decrease in roundness. This is the main cause.

Therefore, as a method to improve dimensional accuracy, the width dimension B
It is conceivable to make the rolling conditions uniform in order to eliminate the fluctuation factors. To achieve this, it is necessary to control the temperature of the heating furnace over its entire length, to prevent uneven heating by increasing the soaking time, and to control the rotation speed of each stand by detecting the tension between the stands during rolling. However, this requires very expensive equipment and fuel costs, and also requires a technically very advanced control system.

Next, there has been an attempt to adjust the size by installing a 20-L type rotatable non-driven roller on the exit side of the finishing rolling mill and performing sizing with light rolling using this roller.

As mentioned above, in normal rolling, in order to prevent chewing, the width part with large dimensional fluctuations is slightly reduced (tendency to be underfilled).
However, in this case, in order to be able to size this part, the width part is actively rolled to a larger size than the intended size by giving it a tendency to fill up, and the direction of the finishing roll axis is A 20-L type sizing roller that is pivotally supported in a direction perpendicular to the sizing roller is used to perform sizing by applying light pressure so that the width portion, etc. becomes the desired size (Japanese Patent Publication No. 3285/1985). , JP-A-55-10359, etc.).

However, even in this case, due to sizing, a slight bulge occurs in the non-contact area of the roller, resulting in ±O, Ir
There has been a problem in performing precision rolling of less than m. Moreover, adjusting the opening degree of the roller requires skill, and, for example,
As you can see in Figure 2, the gap is adjusted using a lever arm, and since there is a lot of play in the structure and it is not possible to increase the rigidity, it is necessary to make fine adjustments after rolling and measuring the material dimensions. As a result, it was not possible to follow the time-series changes in heating temperature, and therefore it was not possible to avoid a decrease in productivity, and the pass rate of precision rolling could not be high.In addition, the above-mentioned uneven width part during sanding could be eliminated. For this reason, there is a method in which sizing rollers of the same type are further arranged perpendicularly to the rear, and the bulge formed by the previous sizing roller is sized by the subsequent sizing roller (Japanese Patent Laid-Open No. 55-10359, Japanese Patent Application Laid-open No. 55-10359). 1
26302, etc.).

However, in this case as well, as long as the sizing roller is of the 20-mill type, there is a width difference in the width direction, and this is not a fundamental solution for ultra-precision rolling. In addition, since the equipment becomes more complex, it takes more than twice as much time to adjust it, resulting in extremely low productivity during actual operation.

(Process leading to the establishment of the present invention) Based on the above knowledge, as long as sizing is performed from two directions, there will be a width difference in the width direction, so ±0.10i
It was found that it was not possible to aim for ultra-precision rolling of less than n or less than ±0.051 m. In order to avoid this problem of widening, it is desirable that the entire surface be uniformly constrained.

(2) Therefore, the inventors of the present invention first considered replacing the sizing roller with a conical die and conducted an experiment. In this case, it was thought that the entire circumference would be uniformly constrained and the roundness would be high.

However, even when the outer diameter is reduced by about 1%, during hot sizing of round steel with a diameter of 30 mm or less, the material often gets stuck at the die inlet, resulting in buckling of the material. Of course, the die was placed as close as possible to the exit of the finishing roll. Moreover, in the case of conical dies, such hot extrusion requires lubrication,
Since it is difficult to cool the die, there are also problems in that it is difficult to avoid seizure and thermal expansion of the die.

■Next, we considered the application of sizing using multi-directional rollers, which are generally considered to have less width edge during rolling.

As mentioned above, from the standpoint of width, it is desirable to achieve uniform restraint as much as possible all around the circumference, and for this purpose, the more rollers there are, the better. There is a self-determined upper limit to the number of rollers because the number of free surfaces of the rollers becomes large, making it impossible to restrain those parts, and because the support parts of adjacent roller shaft necks tend to interfere with each other due to the structure.

[In the case of 3-way sizing] Therefore, the present inventors first studied a 30-L type sizing roller.

However, when the finishing mill is a two-way rolling mill, if finishing rolling is performed with a filling tendency in the width part and shoulder part as shown by the dashed line in Fig. 6, and then sizing is performed, The width portion and shoulder portion, which require dimensional adjustment through sizing, and the free surfaces between adjacent rollers of the sizing roller overlap, making it impossible to combine the geometric relationships well.

[Case of 4-way sizing] Next, sizing using a 40-rule sizing roller was studied.

In this case, unlike the 30-roll type, the rollers can be positioned at the width part and shoulder part of finish rolling, and sizing can be performed in this state. Therefore, we installed a 40-ru type sizing roller on the exit side of the finishing rolling mill and investigated its effect.
- There is no width part due to the round shape, ±0.0511
It was found that an outer diameter accuracy of .

[In the case of 5-way sizing or more] In the case of 50-rule type, 60-rule type, and 30-rule type, the free surface between adjacent rollers is the width part to be sized on the finish rolling mill exit side, Full circumference sizing is not possible because it overlaps the local position. Moreover, in the case of 70 mm or larger, this problem becomes even more pronounced and the housing structure has to be increased in size. Further, as for the number of rollers, from the above study, since the precision rolling effect can be sufficiently achieved with a 40-roll type, it is pointless to increase the number of rollers any further.

Based on the above considerations, the sizing rollers installed on the exit side of the two-way finishing rolling mill will be of the 4 [1-roll type].
It was found that extremely remarkable effects were produced, and super-precision space rolling of 10.05 mm could be achieved.

The present invention aims to solve the above-mentioned conventional problems (achieved through various experiments and research conducted by the present inventors), and discloses a method for rolling a round steel bar with high dimensional accuracy, that is, high roundness, and a method thereof. It is an object of the present invention to provide a rolling roller device for use in the method.

(Means for Solving the Problems) The first aspect of the present invention is to provide a pair of opposed rollers supported perpendicularly to the axis of the final rolling roll on the exit side of the final rolling roll of a continuous rolling mill for producing round steel bars. and a pair of opposing idle rollers supported perpendicularly to the idle rollers in the same plane. This is a method for rolling a round steel bar, the gist of which is to correct the filling tendency portion of a round steel bar that has been rolled so that the shoulder and width portions of a dimension hole type have a filling tendency.

The second aspect of the present invention is a rolling roller device disposed on the exit side of the final rolling roll of a continuous rolling mill for producing round steel bars, in which a pair of freely rotatable rollers are pivotally supported to face each other. Then, the four rollers are connected at the same distance to a housing in which two pairs of rotatable rollers supported perpendicularly to each other in the same plane are housed. This rolling roller device is equipped with a mechanism for moving it away.

By the way, the rolling roller device according to the present invention has the following features: i) the housing has high rigidity, ii) the rolling reduction is easy to adjust and the setting dimension can be adjusted in the order of 0.010, and iii) it has a compact structure and is suitable for finishing rolling mills. It is necessary to satisfy the following conditions: that they can be brought close to each other. The reason for this is, as mentioned above, that with a 20-inch sizing roller, the roller gap is adjusted by a combination of adjustment by the opening of the lever arm and fine adjustment by rotation of the eccentric shaft of the roller shaft. ing. However, with this type of structure, there is a limit to the rigidity of the lever arm part, and it requires P-drilling to adjust the gap, and it is also necessary to actually roll it, measure the steel dimensions, and make fine adjustments again. .

On the other hand, when using a 40-hole type, the eccentric adjustment mechanism cannot be of the lever arm type as described above. Therefore, 3
It is necessary to use a system in which the roll shaft neck is supported by an eccentric force, such as that used in rolling mills, but if this structure is used as is,
The housing becomes larger, and the roller diameter must also be increased. In this case, it becomes impossible to place the sizing roller close to the finish rolling roll exit, and as the diameter of the roller increases, the contact area at the rolling portion also increases, resulting in an increase in passing resistance at the roller. Furthermore, if the material is of a narrow size, there is a possibility that the material will buckle, and after the material has been rolled by the finishing mill, it will not be able to pass through the sizing rollers solely due to the inertial force of the material. Therefore, it is necessary to place a pinch roller in front to pull out the material, which requires more equipment, and
There was a problem that handling flaws were likely to occur at that time.

For the above reasons, it is necessary to maintain a structure that is as compact and highly rigid as possible.

In addition to the precision finishing of the roller device according to the present invention, it can also be used in a method of applying rolling to shape and changing the diameter of the product.

(Embodiment) The present invention will be described below based on an embodiment shown in FIGS. 1 and 2.

FIG. 1 is a partial cross-sectional view showing the structure of a rolling roller device according to the present invention.

In the figure, reference numerals 11 to 14 denote rollers for correcting the filling tendency portion of a round steel bar that has been rolled so that the shoulder and width portions of the final rolling roll of the continuous rolling mill have a filling tendency. For example, rollers 11 and 12 and rollers 13 and 14 are supported in pairs and are opposed to each other. That is, the axes of the rollers 11.12 and 13.14 are disposed at an angle of 90 degrees and coplanar within the integral housing 15.

Reference numeral 16 designates the shafts of the rollers 11 to 14, and in this embodiment, the rollers 11 to 14 are rotatably attached to the shaft 16 via an eccentric sleeve 17 that is keyed to the shaft 16, for example, via a tapered roller bearing 21. installed. Therefore, when the shaft 16 is rotated by a required angle, the eccentric sleeve 17 is rotated by the same angle together with the shaft 16, and the rotation of the eccentric sleeve 17 causes the rollers 11 to 14 to move in the direction perpendicular to the axis I6, that is, in the direction of the housing 15. It moves toward and away from the center.

Bevel gears 18 are keyed to the shaft 16 so as to sandwich the rollers 11 to 14, and are attached to the housing 15 via ball bearings 19 so as to be rotatable integrally with the shaft 16. These bevel gears 18 are keyed to all the shafts 16 of the rollers 11 to 14 so that adjacent bevel gears 18 mesh with each other. 16, all the shafts 16 rotate around the center of the housing 15, and by the action of the eccentric sleeve 17, the housing I5
The rollers 11 to 14 move towards and away from the center of the image.

That is, by adjusting the positions of the eccentric sleeves 17 on each shaft 16 in the same way, by rotating one shaft 16, the rollers 11 to 14 with the same dimensions are aligned with respect to the center of the housing 15. They move toward and away from each other.

Note that one of the shafts 16 (in this embodiment, the shaft of the roller 11) is extended to extend outside the housing 15, and the rollers 11 to 1 are extended from the outside of the housing 15.
Make it possible to adjust the position 4, that is, the correction flat. In the figure, reference numeral 20 denotes a thrust bearing interposed between both side surfaces of each roller 11 to 14 and the housing 15, and is used to improve correction accuracy.

Although not shown in this embodiment, the shaft 16 of the roller 11
A scale may be provided on the extending portion from the housing 15 so that the amount of correction can be confirmed, and a guide may be installed on the entrance side of the rolling roller device of the present invention to smoothly guide the round steel bar from the final rolling roller. Of course, it may also be possible to do so. Furthermore, to adjust the positions of the rollers 11 to 14, in this embodiment, a method was adopted in which an eccentric sleeve 17 was fitted in the center of the shaft as shown in FIG. It is also possible to process it eccentrically.

However, the roller shaft neck portion and roller shaft connection portion should not be eccentric. This is because, during dimensional adjustment, the engagement surfaces of the connecting portions shift, resulting in a decrease in dimensional accuracy.

That is, the rolling roller device according to the present invention has the configuration described above, and its characteristics are as follows.

1) The rollers 11 to 14 are fitted to the shaft 16 via tapered roller bearings 21, and the rotation of the rollers 11 to 14 is caused by the rotation of the shaft 16.
6 is free.

ii) The neck portion of the shaft 16 is held in the housing 15 via a ball bearing 19, and both ends thereof are connected to each other by a bevel gear 18 or the like.

iii) The eccentric sleeve 17 or the like gives the shaft 16 an axially symmetrical eccentricity with respect to the pass line, and by rotating one shaft 16, the eccentricity of the four shafts 16 can be adjusted simultaneously.

iv) The housing 15 is made by accurately processing the neck support part of the shaft 16 into two pieces, one on the front and the other, the neck of the shaft 16 is held between them, and the housing 15 is tightened in place with bolts.

Note that it is desirable that each housing be made into one piece in terms of dimensions and rigidity.

(2) The side surfaces of the rollers 11 to 14 are slidably held in the housing 15 via thrust bearings 20 and the like.

That is, by adopting the configuration of the present invention, a compact, highly rigid, and easily adjustable rolling roller device can be realized.

The method of the present invention uses a rolling roller device having the above-mentioned configuration, and the rolling roller device is arranged on the exit side of the final rolling roll of a continuous rolling mill, and the local area and width of the final rolling roll are adjusted to the desired dimensions and width. This process corrects the filling tendency of a round steel bar that has been rolled so that it has a filling tendency.

Next, specific examples of the present invention will be explained.

A 40-roll type rolling roller device shown in No. 1M was installed close to the finishing roll of a group of continuous rolling mills that finish a 180mm billet to 40φ with 16 stands, and its straightening effect was studied. The experimental conditions are as follows.

・Material: 548C ・Heating temperature: 1100°C (before charging continuous rolling mill group) ・Continuous rolling mill group: HV rolling mill orthogonal arrangement Stands 1 to 10 are diamond square shaped, stands 11 to 16 are oval round Hole type series/Roller: Roller diameter 120φ (groove bottom diameter) Eccentricity IQ,
3 Tobisho / outer diameter correction amount: 0.1 + n, 0.3 Tsuru, 0.5 va,
0.7 mm (4 levels) Finished material length: Approximately 300 m For comparison, dimensions by normal rolling were also measured. When straightening was performed, the width part was given a tendency to fill up during finish rolling. Further, the temperature at the exit of the finishing mill was about 1000°C.

The results are shown in Table 1 and Figure 2.

Table 1 As a result, as shown in Table 1, ±0.
For an outer diameter accuracy of 2 mm, ・0.1 mm sizing results in ±0.161 hazy, ・0
, 3 Iris I sizing is ±0.0511, ・0.5
It was found that the sizing of the seal converges to ±0.05 mm, and the sizing of the 0.7 forehead converges to ±0.13 mm over the entire circumference and length.

It has become clear that extremely precise rolling of ±0.05++ m can be stably achieved by applying the sizing amount in accordance with the difference in diameter of the finishing rolling mill.

Incidentally, if the sizing amount was made too large, an unpressed lower part of the roller (a gap between adjacent rollers) remained, so that outer diameter accuracy could not be obtained.

That is, it is most desirable to set the sizing amount so that the dimensions of the full part (width part) of the front and rear finishing rolling mills are made equal to the desired outer diameter dimension (vertical dimension).

(Effects of the Invention) As explained above, the present invention provides a pair of opposing idle rollers supported perpendicularly to the axis of the final rolling roll on the exit side of the final rolling roll of a continuous rolling mill for producing round steel bars. A rolling roller device is arranged in which a pair of opposing idle rollers that are supported perpendicularly to these idle rollers are housed in the same plane, and the desired size and hole shape of the final rolling roll is determined by the rolling roller device. correcting the filling tendency portion of the rolled round steel bar so that the shoulder and width portions of the rolled steel bar have a filling tendency; In a rolling roller device arranged to correct the filling tendency portion of a round steel bar rolled so that the shoulder and width portions of a period-sized hole shape have a filling tendency, a pair of two rollers are supported so as to face each other. The four rollers are housed in a housing in which a rotatable roller and a pair of rotatable rollers supported perpendicularly to the axes of these rollers so as to face each other are housed in the same plane. Since a mechanism is provided to move the two members toward and away from each other by the same distance, it is possible to easily obtain a round steel bar with high dimensional accuracy, that is, high roundness.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the configuration of the device of the present invention, Fig. 2 is a drawing showing the effect of the method of the present invention, Figs. 3 and 4 are explanatory diagrams of the conventional method, and Fig. 5 is a diagram of the conventional method. FIG. 6 is a diagram illustrating problems when using a 30-L type sizing roller. 11 to 14 are rollers, 15 is a housing, 16 is a shaft, 1
7 is an eccentric sleeve, 18 is a bevel gear, 19 is a ball bearing, 20
is a thrust bearing, and 21 is a tapered roller bearing. Patent Applicant: Sumitomo Metal Industries, Ltd. Ka2W/E Mountain (#Senken $me/5's Big Brother (^) Fig. 3 2"L" Fig. 5 Gore material tip 46゛En distance Figure 6

Claims (2)

[Claims] (1) On the exit side of the final rolling roll of a continuous rolling mill that manufactures round steel bars, there is a pair of opposing idle rollers supported perpendicular to the axis of the final rolling roll, and a pair of idle rollers supported perpendicularly to the idle rollers. A rolling roller device is arranged in which a pair of opposing idle rollers are housed in the same plane, and the rolling roller device tends to fill the shoulder and width portions of the holes with the desired dimensions of the final rolling roll. A method for rolling a round steel bar, which comprises correcting the filling tendency portion of the rolled steel bar. (2) In a rolling roller device disposed on the exit side of the final rolling roll of a continuous rolling mill that manufactures round steel bars, a pair of freely rotatable rollers that are pivotally supported to face each other, and the shafts of these rollers 2 which are pivoted to face each other at right angles to
A rolling roller device for producing round steel bars, characterized in that a housing in which a pair of rotatable rollers are housed in the same plane is provided with a mechanism for moving the four rollers toward and away from each other by the same distance.