KR830000352B1 - Rolling equipment for metal workpieces - Google Patents

Abstract

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Description

Rolling equipment for metal workpieces

1 is a graph showing the relationship between the forward force and the corresponding low angle.

2 is a diagram for explaining the corresponding contact angle.

(Figure 2a illustrates the inclination angle of the groove, and Figure 2b illustrates the contact angle located at the bottom of the groove of the roll.)

3 is a graph schematically showing a state in which the rolling load changes over time.

4 is a graph showing the relationship between the rolling speed and the corresponding contact angle.

5 is a schematic view showing an embodiment of the rolling mill of the present invention.

6 is a front view showing an embodiment of the guide roller used in the rolling mill of FIG.

7 is a diagram showing a groove arrangement of a diamond system.

8 is a diagram illustrating the arrangement of grooves in boxed and elliptical systems.

9 is a diagram illustrating the arrangement of a typical representative rolling mill.

(Figure 9a-c shows the arrangement of the billet rolling mill, and Figure 9d-e shows the approximate continuous rolling mill of the rod.)

10 is a diagram for explaining an arrangement example of a rolling mill according to the present invention.

(Fig. 10a shows a billet rolling mill, Fig. 10b shows a bar rolling mill, and Fig. 10c shows an approximate continuous rolling mill of a rod.)

11 is a block diagram of an adjusting device in the arrangement of the rolling mill according to the present invention.

12 is a diagram for explaining the accuracy of the groove.

13 shows an embodiment of a groove used in rolling a bar or rod.

The spring invention relates to apparatus for producing rolled plates, billets, bars and rods made of metal workpieces.

For known rollings where the reduction in cross-sectional area on a single pass is within 20-30%, the contact angle θ between the workpiece and the rolling mill must be taken into account to determine the maximum level of cross-sectional area reduction. That is, in order to perform rolling safely under the conditions of rolling speed and rolling work, the contact angle θ must be in the relationship of θ <tan ^-1 μ (μ represents the coefficient of friction in the engagement between the work and the rolling mill). Usually it was common to determine the maximum level of appropriate cross-sectional reduction within this range of contact angles.

On the other hand, the following relationship is known with respect to the coefficient of friction between the workpiece and the rolling mill, which assumes the coefficient of friction in the stable rolling condition after the end of engagement is μ '.

tan ^-1 μ '> tan ^-1 μ

From this relationship, the rolling having a large contact angle, that is, the rolling having a severe cross section reduction in the?

tan-1μ의 관계로 접촉각도 θ를 유지하도록 조정되며, 그리고 가공물이 밀리는 하중의 크기에 따라 전술한 간격을 갖는 로울 사이로 연속적으로 밀리는 동안 압연이 수행되는 것을 특징으로 한다.US Patent Application No. 759,868 is known as a method of rolling metal workpieces with a significant reduction in cross-sectional area. In this method, the metal workpiece is rolled by a rolling mill supported by working rolls so that the rolls are not moved in the direction of the workpiece.

The contact angle θ is adjusted to maintain a tan-1μ relationship, and the rolling is performed while the workpiece is continuously pushed between the rolls having the above-described spacing according to the magnitude of the load being pushed.

Here, the center point of the rolling is due to the pushing force, which is in the plane where the working roll and the workpiece contact each other. However, this method uses, for example, a main-sized pusher system as a large dimension pusher device which continuously and steadily pushes the workpiece along the entire workpiece length between the working rollers. In this device, the workpiece is pushed by the main pusher in the primary stand and the workpiece is pushed through the primary stand in the secondary stand. However, even in such a device, the passage is limited to two in order to continuously move the workpiece through the work roller, and it is practically impossible to move forward with two or more passages, and thus the limit to make the rolling mill small with the rolling with high reduction is limited. Will follow. Furthermore, there is a method of advancing the workpiece to push the workpiece to the roll interval by the pinch roll or the rolling mill itself. When the pusher device is used in this manner, the above problem can be eliminated. However, if the forward force goes to zero between the pinch rolls and rolling mills or between rolling mills, the tribute is rolled unstable. Because of this phenomenon, there is a risk of incomplete meshing, and in addition, especially the rolling work, elongation rate and quality adversely affect, that is, a larger variation occurs in the dimensions of the width direction. In order to solve this problem, it is also possible to perform rolling by connecting the front and rear of the workpiece by welding, but this operation requires another facility, which causes technically and extremely complex problems in equipment. The forward force applied to the workpiece also affects the deformation of the workpiece between the working rollers, so that the spread in the width direction over the entire length of the workpiece is increased and leads to deterioration of the deformation efficiency.

US Pat. No. 3,533,997 is known as another embodiment in which the contact angle θ becomes θ> tan ⁻¹ μ and severely reduces the cross-sectional area, ie, rolls the workpiece. This rolling method is a method of performing a direct reduction in continuous casting, in which the shear of the workpiece opens the gap of the working rolls to pass through a certain range between the working rolls, and the workpiece is pulled by the working rolls. The roll spacing is then smaller to carry out the rolling with a large contact angle. In this rolling method, it is possible to roll so as to reduce the cross-sectional area of the workpiece relatively large, but the elongation of the tip portion of the workpiece is reduced.

This approach has the other problem that the roll spacing must be changed for all other workpieces, and the roll equipment becomes complicated and large. Furthermore, in this rolling method, the cross-sectional area of the leading part of the workpiece is larger than that of the subsequent part and changes rapidly so that an active moving guide is required on the inlet side of the next rolling stand, and the rolling speed also changes according to the change of the cross-section. And complicated adjusting equipment. Also in this rolling method, in the case of groove rolling, the shear portion of the workpiece having a large cross-sectional area is not suitable for the groove, and the rolling of billets, bars and rods is almost impossible.

To date, the methods of assisting the engagement of the workpieces have been envisaged by cutting the tip of the workpiece or by advancing the cold or hot workpiece against the trailing edge of the other workpiece to advance it between the working rolls. However, these methods are usually used in rolling with a relationship of contact angle θ <tan ⁻¹ μ. Moreover, this method has problems such as production capacity, facility maintenance, and stability of work, and thus cannot be practical.

It is an object of the present invention to solve the above-mentioned problems in rolling which greatly reduces the cross section and also to provide an apparatus for rolling a metal workpiece into a plate, billet, bar or rod with high working efficiency and productivity without exhibiting any drawbacks. have.

Another object of the present invention relates to a simple rolling device which greatly reduces the cross-sectional area of a workpiece by adding a simple device to an already installed press.

FIG. 1 schematically shows the relationship between the force for advancing the workpiece between the working rollers and the contact angle of the working rollers relative to the working rollers. In the graph, the forward force is represented as δ / k, which is the ratio between the compressive stress generated in the workpiece when moving forward and the yield stress k of the workpiece during rolling. The contact angle is also represented by the corresponding contact angle θe, which corrects the inclination angle of the work roller groove. As shown in FIG. 2, the angle α is defined between the work surface 3 of the groove 2 of the work roller 1 and the line 1 parallel to the roll axis. In addition, as shown in Fig. 2b, the low tactile angle θ at the bottom diameter D ₀ of the roll groove is represented, and the corresponding contact angle θe is expressed as follows.

θe = tan-1 (cosα × tanθ)

Thus, in the case of an elliptical groove, the elliptical groove is replaced by the angular groove and the inclination angle of the angular groove becomes the inclination angle of the elliptical groove. The replaced angular cross section and the longer diagonal are the same as the cross sectional area of the elliptical groove and the part of the long axis, groove rolling and flat when the corresponding contact angle θ e is used since α = 0, cosα = 1 when rolling by a flat roll. Both rolling can be shown.

The curve I shown in FIG. 1 is therefore a line representing the corresponding contact angle in the range to engage the workpiece in the roll. Point A represents the corresponding contact angle in the range of clamping the workpiece between the working rollers without forward force and the amount is θ e = tan ⁻¹ μ as described above. Curve II is a line showing the extent to which the workpiece is rolled in a rigid state after engaging the workpiece between the working rollers, that is, the slippage between the workpiece and the working rollers.

For example, this shows that rolling is possible with a high reduction of the part with the maximum corresponding contact angle D, given a forward force b. And in this case curve II shows that after the workpiece has been bitten into the work-roll, the rolling can be carried out firmly with the forward force b '. Point B also shows the corresponding contact angle in the range in which the workpiece is firmly rolled without forward force after the workpiece is bitten into the working roll, and the amount is θ e = tan ⁻¹ μ ′ as described above.

The range where the contact angle θe is from 0 to A is a range in which the workpiece is engaged in the working roller with a zero forward force. Normal rolling to reduce the cross section determines the rolling conditions based on the contact angle within this range. The range of BC is also the range in which the workpiece meshes with the forward force within the yield stress during rolling of the workpiece.In addition, even after the end of the engagement, the forward force continues to be applied so that rolling is carried out and the above-described high cross-sectional reduction rolling method This falls within this range. Furthermore, assuming a forward force of 1.0, the engagement can be performed at the corresponding contact angle at point C. Also, the minimum required forward force to continue the solid rolling is the forward force C, which is represented by intersecting a perpendicular line to the abscissa from the point B 'on curve II with the abscissa. Thus, if the forward force is exceeded 1.0, the workpiece at the time of biting will accept a higher forward force than the yield stress and deform before reaching the rolling mill and a corresponding range of corresponding contact strength greater than point C falls within this range. For example, extrusion methods with a large reduction in this range are used to roll container receiving heated workpieces and at the same time advance them into the holes due to the advancement carried out by the forwarding device.

This rolling method has a range of the contact angle in the range of AB shown in FIG. 1, and the amount of the contact angle is not compared with that of the rolling method with a large reduction and the extrusion method with a large reduction, and according to a conventional method. Greater than decrease. In addition, continuous rolling that passes two or more times in a large reduction extrusion method is practically impossible, and continuous rolling two or more times in a large reduction rolling is limited as described above. Another rolling device of the invention has the advantage of being able to roll the workpiece more than once.

In general, in rolling of billets, bars and rods, the overall elongation from the starting material to the product is 400-500, as is often used, and the relationship between the total elongation and the λ totalization and the elongation for each pass is as follows: have.

λ totalization = λ ₀ , λ ₂ , λ ₂ . … … … … … … … … … λ _n

The main technical problem is how the elongation at each pass becomes large or how to continue several rollings at high elongation. The focus of the present invention is here.

The forward force used in the rolling apparatus according to the invention is basically in the range of 0-a in FIG. 1 and again the range of cross-sectional reduction that can be achieved in this case is AB in the range of the corresponding contact angle as described above. Ie, tan ⁻¹ μ <θe <tan ⁻ '

Thus, when the workpiece is engaged into the working roll, the corresponding contact angle B can be achieved by applying a forward force a. Also in the present invention, after the workpiece is engaged in the working roll, rolling is continued unless a stress in the direction along the rolling line is generated on the workpiece in such a state. The time at which the leading end of the workpiece reaches the roll center line m (see also FIG. 2B) in the overall cross-sectional area is the time when the engagement of the workpiece is finished. Even if some of the tip of the workpiece (for example, metal debris) reaches the roll center line, the engagement of the workpiece is not completed.

3 shows the change of the rolling load during rolling, where point e represents the first engagement, ie the initial contact of the workpiece and the work roller, f represents the end of the bite, and point g represents the directional stress along the rolling line. It is indicated that it is no longer applied to the workpiece, and points i each show completeness. In FIG. 3, the part between the point e and the point g is an unstable rolling section in which the rolling load fluctuates greatly. Also, the part between the points g and h is the section in which the rolling load is fixed to the F value and the rolling is performed stably.

Even if the forward force is zero after the rolling has reached a stable state, the corresponding contact angle in FIG. 1 is in the range below the curve II, and thus no slip occurs between the workpiece and the work roller.

Thus, the state of point f can be detected by a load cell, a high temperature metal detector, or the like. The point g can also be changed by adjusting the peripheral speed of rolling, for example the following way can be taken. That is, the average rolling load F during stable rolling is known from the past rolling practice, and only when the workpiece is bitten by the work roll, the rolling load F occurs, and when the time reaches 0.8F, the timer is operated and a suitable time has elapsed. The circumferential velocity of is adjusted to remove the directional stress along the rolling line on the workpiece.

As described above, the magnitude of the forward force is essentially the magnitude in the range of 0-a in FIG. However, in order to obtain a stable forward force, the magnitude of the forward force is such that the compressive stress generated on the workpiece by the forward is 1% or more. The forward force can also be the size of the point at which the workpiece is bitten. However, before the workpiece is snapped into the working roll, the compressive stress generated on the workpiece should be below the yield stress of the workpiece during rolling in order to prevent the stress generated on the workpiece from exceeding the yield stress and plastic deformation. In other words, δ / k in FIG. 1 is required to be 1.0 or less.

tan^-1μ'로 되는 로울 간격으로 이루어지는 작업로울과 가공물 사이의 슬립을 발생시키지 않는 속도로 된다.As described above, after the workpiece is engaged, stable rolling is performed, but the circumferential speed of the roll has a corresponding contact angle θe of tna ^-1 μ <θe

It is a speed that does not generate slip between the work roller and the workpiece formed at the roll interval of tan ⁻¹ μ '.

As shown in FIG. 4, there is a close relationship between the rolling speed Vm and the given contact angle θe. The conclusion of FIG. 4 is obtained from hot steel workpieces.

Curve III in FIG. 4 is evident as a result of several experiments and shows the range curve of slip generation between work material and working roller under stable rolling when the forward force is zero. The upper region k of curve III is an area where continuous rolling is difficult due to slip occurrence. Curve IV shows the results of experiments conducted by the inventors in the case of hot rolling using a rolled surface and is a range curve of zero engagement force. The upper region L of curve IV indicates an area where engagement is difficult unless forward force is applied, and the lower region M of curve IV is an area that can be engaged without applying forward force. This curve is in full agreement with the results described by Double Oil Tafel (literature steel and iron 1921). Curve V is a curve showing the maximum level of the corresponding contact angle used in this hot rolling, and it can be said that the maximum clearance is given for the close angle. Curve VI does not cause problems from the point of slip, but in the upper region N of curve VI grooves or defects occur due to falling or tightening of the workpiece and also show curves of areas of insignificant importance.

The rolling speed employed in the present invention in FIG. 4 is the speed corresponding to the area enclosed by curves III, IV and VI. At this speed, as can be seen from the above, between the workpiece and the work roller under stable rolling conditions Slip does not occur.

Therefore, when the rolling speed such as the actual billet rolling mill and the loaded rod rolling mill is equivalent to the rolling speed shown in Fig. 4, it is about 2.5 M / S or less. That is, the rolling speed range employed in the invention in FIG. 4 is substantially suitable for rolling facilities for billets, bars and rods. Conversely, this rolling method shows that it is particularly effective for rough rolling billets, bars and rods. Moreover, in terms of high speed, curves III and VI approach each other so that there is no substantial difference between the two curves.

This rolling speed is generally 2-5 M / S.

The specific way of carrying out the rolling of the invention is described as follows.

5 shows one embodiment of the rolling mill of the present invention. The roller spacing of the working roller 6 of the primary stand is similar to that of the normal stand, so that the contact angle θe becomes θe <tan-1μ, but the roller spacing of the working rollers 6a and 6b of the secondary and tertiary stands 5a, 5b The contact angle θe is set in advance so that tan ⁻¹ μ <θe tan ⁻¹ μ '.

At the primary point, the workpiece M is supplied to the primary stand 5 by a normal device, that is, a roller table, but since the roller spacing is preset as described above, the workpiece M is not dependent on any special device, Engage in work roller 6. The workpiece M passing through the primary stand 5 reaches the primary stand 5a as long as it is guided by the warpage preventing device 16. Until the tip of the workpiece M reaches the secondary stand 5a, no directional stress along the rolling line is generated on the workpiece. However, when the front end of the work piece M reaches the secondary stand 5a, the work piece 6a does not immediately engage the work roll 6a because the roll spacing of the work roller 6a of the second stand 5a is preset.

And the compressive stress of the direction along a rolling line is generate | occur | produced on the workpiece arrange | positioned between the primary stand 5 and the secondary stand 5a. In this state, since the workpiece M is continuously discharged from the primary stand 5, the compressive stress of the workpiece M gradually increases, and finally exceeds the value shown in the curve I of FIG. 1, and the workpiece M is the secondary stand ( To the working roll 6a of 5a).

When the workpiece M is completely bitten by the working roll 6a of the secondary stand 5a, the rolling load F shown in FIG. 3 can be found by detecting it by means of the load cell 8a. The sense signal is transmitted to the tension sense signal amplifier 11a. On the other hand, the load cells 9 and 10 are installed in the primary stand 5, and the load cells 9a and 10a are installed in the secondary stand 5a and the primary stand 5 and the secondary stand. The workpiece tension between (5a) (ie the direction stress and minimum value along the rolling line represents the compressive stress) is sensed by the load cells 10 and 9a.

The tension sensing signal is amplified by the tension sensing signal amplifier 11a and also transmitted to the tension adjusting device 12. The output signal from the tension adjusting device 12 is compared with the output signal from the comparator 13a in the comparator 13. Again, the rotational speed of the drive motor 7 is detected by the oscillator 15 for the rotation system and the signal is applied to the automatic speed adjusting device 14 together with the signal from the comparator 13. The automatic speed adjusting device 14 adjusts the rotational speed of the drive motor 7 so that the strength does not act on the workpiece M disposed between the primary stand 5 and the secondary stand 5a.

The workpiece (M) discharged from the secondary stand (5a) is engaged with the tertiary stand (5b), in the case of continuous rolling, the tension adjustment of the workpiece (M) located between both stands is the tension sensing signal amplifier (11b), By adjusting the rotational speed of the drive motor 7a on the basis of signals from the load cells 8b, 10a and 9b by means of devices such as the tension adjusting device 2a, the tachometer oscillator 15a, and the like. do. In this case, the tension between the primary and secondary stands changes, and in order to fix such a change, the output signal corresponding to the output signal from the comparator 13a is used to adjust the rotational speed of the driving motor 7a. In order to transmit to the comparator 13, at the same time the rotational speed of the drive motor 7 is made. As described above, when the speed of the upper stand is changed, the speed of the entire stand is changed continuously. In FIG. 5, only the third stand 5b is shown, but the tension is the same as that of the load cell 10b, the tension adjusting device 12b, 14b, the comparator 13b, and the oscillator 15b. The apparatus is adjusted by adjusting the speed of the drive motor 7b as described above.

For example, although the foregoing is related to adjusting the uplink system, the object of the present invention is not limited to the uplink system but may be achieved by the method of adjusting the downlink system. In this adjustment each device is well known to those skilled in this field and also the rotational speed of the working roller can be adjusted by manual operation so that the tension is zero based on the sensed tension.

Work piece (M) is the second stand when engaged with the work roll (6a) of (5a), second circumferential speed is substantially V _R2 of the working roll (6a) of the primary stand (5a) <λ ₂ and adjusted to V _R1 In the case of regular rolling work, a little compression occurs. In floating, V _R1 and V _R2 indicate the respective circumferential speeds corresponding to the working diameters of the working rolls of the primary and secondary stands under non-tension conditions, and λ ₂ indicates the extension of the secondary stand under non-tension conditions. Indicates.

Of course, even if the circumferential speed of the work rollers of both stands is adjusted to V _R2 ≒ λ ₂ ㆍ V _R1 (here, in the normal rolling operation, the tension and uncompressed state are generated). Is the result of compressive stress, which is finally caught in the work roller. In both cases, when the workpiece is temporarily engaged in the working roller between the two stands, no fixed state in the passage is established. If the circumferential speeds of the working rolls 6 and 6a are also performed at the same circumferential speeds or in a similar value, the speeds of the working rolls 6 and 6a after the engagement is completed. The correction of is done to the minimum degree.

The warpage preventing device 16 is provided with a plurality of pairs of rotation guide rolls 17 which are stretched in front of the work rolls 6a and 6b along the moving direction of the workpiece M. FIG. . As the workpiece M is guided by these guide rolls 17, warping does not occur in the front of the stands 5a and 5b and the workpiece M is guided properly between the work rollers 6a and 6b. . The cross-sectional shape of the passageway formed by the guide roll 17 is similar to that of the workpiece M as shown in FIG. 6B, but these cross-sectional shapes have warpage prevention and guiding functions as shown in FIG. 6C. As long as they remain, they are different.

Thus, for a rolling stand employing severe cross-sectional reduction, the appropriate corresponding contact angle θe at the bottom side is usually chosen with some margin when compared to that of point B shown in FIG.

The reason is that even if it is immediately impervious to the stand at the bottom except for the final stand, it requires the application of forward force, and also the occurrence of difficulties due to sudden confusion during rolling can be avoided.

Furthermore, pinch rolls instead of the first stand 5 are used to snap the workpiece to the second stand 5a. Instead of detecting the completion of the engagement of the workpiece M with the load cells 8a and 8b, this can be done using a known high temperature metal detector.

In the case of grooved rolled grooves, the grooves are formed on the roll by the lathe, but the grooved system of the diamond-diamond system or the diamond-square system shown in FIG. 7 has advantages in operating and obtaining high quality products or achieving high elongation. . In addition, the box-box system or the elliptical-square system shown in FIG. 8 can obtain a high elongation, but there is a risk of falling workpieces or wrinkles or grooves on the grooves, and a high level of operating technology is required. Difficulties are involved. By the way, a square groove having a conventional reduction ratio employed in conventional rolling in the case where the final cross-sectional formation is a billet thin square cross section is disposed behind the diamond groove, and also in the case of round steel rods, a conventional reduction employed in conventional rolling. Rain and square grooves and circular grooves are arranged behind the die grooves.

Although apparent from the foregoing description, in the present invention, a severe cross section similar to the continuous rolling of a conventional cross section reduction method is applied without a tension and a compressive force applied to a workpiece to the extent that difficulty in rolling operation is not entirely present. Reduction continuous rolling can be carried out. This means the removal of rolling under unstable conditions and the dimensions are precise and advantageous in productivity.

Also, rolling is carried out continuously with severe cross-sectional reductions exceeding conventional standards, which is of great advantage in terms of improving the overall elongation.

Also, if one wants to severely reduce the cross section, rolling with severe reduction of the cross section can be achieved by reducing the corresponding contact angle for the relatively larger diameter of the working roller. However, in this case the facility is unnecessarily large and also impractical. In this respect, in the present invention, a rolling mill having a required minimum diameter working roll and having a high cross section can be performed as a simple rolling facility having a high efficiency.

When rolling a starting material of 230 millimeter square steel into a 100 millimeter square product, the present invention is compared with the conventional method in terms of the facility. Table 1 shows a comparison of the diameter of the working roll of the rolling mill for rolling the product.

Table 1

In this table, the roller diameter of the device according to the invention is determined by curve III in FIG. 4 and the roller diameter of the conventional method is determined by curve V. FIG. Therefore, the fifth stand of the present invention performs the rolling with the conventional method of reducing the cross section. As will be evident from the table, the roll diameter according to the invention is very small compared to the conventional diameter. In the conventional method, the above-mentioned large diameter working roller is not actually used, and the diameter of the ordinary roller is 800 mm or less, and the number of stands is adjusted to 7-8 to compensate for the diameter.

Although the work is described in the above in the case of steel, it is evident from the construction, operation and effects of the present invention that the device according to the invention can be applied with a material other than steel, for example aluminum alloy or copper alloy.

Next, the continuous rolling mill of the present invention will be described through comparison with a conventional rolling mill.

9 shows a typical representative rolling mill.

Symbol 21 in the figure denotes a furnace, M denotes a rolled workpiece, and 23 denotes a breaker. In Figs. 9a, 9b and 9c, 6-8 continuous billet mills 24 and 24a are required to obtain 85% overall cross-sectional reduction rate.

In addition, in Figs. 9d and 9e, a similar number of rough bar rolling mills 25 and 25a are required to achieve similar overall cross-sectional reduction. By the way, the symbols 26 and 26a represent wheat after the intermediate wheat.

On the other hand, Figure 10 shows the rolling mill of the present invention.

That is, FIGS. 10a, b, and c show an example of arrangement in the case of producing a billet, a round bar or rod from ingot, blue or continuous casting blue.

The workpiece M heated or heat-blocked to a predetermined temperature by the furnace 21 is extracted by an extraction device (not shown), which is sufficient to roll to severe cross-sectional reduction after the next stand has a low reduction rate. And through the pinch rolls 27, which are adjusted to provide the necessary forward force. Alternatively, the starting material (M) is passed through the rolling mill 27 to facilitate the workpiece bite without the auxiliary forward force to enter the high draw mill 28, that is to say 10-30% regular cross-sectional reduction.

Essentially the above reason means that a device is provided which moves the workpiece to the primary rolling mill and allows the workpiece to slightly bite into a roller, such as a roller table or a simple pinch roller.

The number of components of a high drawing mill with a large reduction in cross section is dependent on the reduction of the overall cross section from the starting material to the product and the effective exit maximum speed of the rolling mill group (i.e., within the effective speed range of the high drawing rolling method shown in FIG. 4). Is determined by The workpiece is then roll mill group 29 having a typical cross sectional reduction of about 10-30% (i.e. one or more of the diminishing roll mills having extremely low cross sectional reduction rates are arranged in this order for shape and size). By passing through), the workpiece is finished to the shape of the product.

Thus, in actual rolling, the work piece is not shown, but becomes a final product through a shear or a cooling device.

tan^-1μ의 압연스탠드를 보여주며, 기호 4 및 51은 tan^-1μ＜θ₂＜tan^-1μ'의 압연스탠드를 보여준다.In Fig. 11, the symbol 31,61 is θ ₁

A rolling stand of tan ⁻¹ μ is shown, and symbols 4 and 51 show a rolling stand of tan ⁻¹ μ <θ ₂ <tan ⁻¹ μ '.

The final stand 51 of rolling with the contact angle θ ₂ becomes a pivot stand. The reason is that the rolling range with the contact angle θ ₂ as shown in FIG. 4 is affected by the limit of the rolling speed, and thus the method of adjusting the rotational speed of other rolling mills is affected by the limit of the maximum rolling speed. Therefore, the method of adjusting the rotational speed of the other rolling mill is preferably by adjusting the maximum rotational speed of the working roller (rolling speed) of the final stand 51 which is the maximum rolling speed.

The adjustment method is shown in FIG. 11 using the non-tension and non-compression adjustment system of the current memory device as an embodiment.

In the drawings, symbols 32, 42, 52 and 62 are current detectors, symbols 33, 43, 53 and 63 are current memories, 34, 44, 54 and 64 are rotation controllers and 45, 55 are rolling speed controls. Device, 46,56 is a signal for providing a critical speed range, 48,58 is a pilot oscillator and 49,59 is a high temperature metal detector.

The workpiece M is bitten by the rolling stand 31, and at this moment, the constant current value excluding the impact portion is detected by the current detecting device 32 and stored in the memory device 33. Next, the workpiece is bitten by the rolling stand 41 after receiving the auxiliary advance force from the rolling stand 31. At this time, a compression force is temporarily generated between the rolling stand 31 and the rolling stand 41, and the current of the driving motor of the rolling stand 31 is increased. However, when the bite is completed, it becomes a fixed current value, which is detected by the rotation adjusting device 34 to adjust the rotational speed of the roll of the rolling stand 31 and is also compared with the previously stored current value. Thus, non-tension and uncompressed states occur. In this case, the completion of the bite is confirmed by the high temperature metal detectors 49 and 59, which can be adjusted using the signal, and in the event of a misalignment, the signal can be used as a countermeasure against the previous value. .

The workpiece M is engaged by the rolling stand 51 under an auxiliary forward force of engagement from the rolling stand 41. However, the adjustment between the rolling stand 51 and 41 is performed similarly to the adjustment between the rolling stand 31 and the rolling stand 41. However, before adjusting the rolling stands 41 and 51, it is good to complete the adjustment between the rolling stands 31 and 41. FIG.

Therefore, of course, the rotational speed of the working roll of the rolling stand 31 in the rolling stands 41 and 51 changes by continuous adjustment when the rotational speed of the roll of the rolling stand 41 changes.

tan^-1μ를 가지게 되므로 물림의 보조전진력은 불필요하게 되며, 안정한 압연에서의 비장력 및 비압축의 조정은 압연스탠드(61)의 작업로울의 회전속도를 조정함으로써 보상된다. 이와 유사한 조정이 연속스탠드에 적용된다. 따라서 피보트스탠드(51)의 압연속도는 압연속도 조정장치(55)에 의해서 항상 조정되며 또한 제4도에서의 압연속도 V_m및 해당 접촉각도 θe의 관계로 부터 측정된 속도표준치(56)과 비교되며 그 범위내에서 조정된다. 이러한 경우 예를들면 압연스탠드(51)의 압연속도의 조정이 요구되는 경우, 전체적인 선속도를 변화시키는 방법이 채택된다.The workpiece is then bitten by the rolling stand 61 but in this case the rolling mill is θ1

Since tan ⁻¹ μ, the auxiliary forward force of the bite becomes unnecessary, and the adjustment of the specific tension and non-compression in stable rolling is compensated by adjusting the rotational speed of the working roller of the rolling stand 61. Similar adjustments apply to continuous stands. Therefore, the rolling speed of the pivot stand 51 is always adjusted by the rolling speed adjusting device 55, and also the speed standard value 56 measured from the relationship between the rolling speed V _m and the corresponding contact angle θe in FIG. Are compared and adjusted within that range. In this case, for example, when adjustment of the rolling speed of the rolling stand 51 is required, a method of changing the overall linear speed is adopted.

Although one embodiment of a current memory system has been described from the foregoing, the above-described adjustment method is sufficiently effective when uniform heating is sufficiently performed in a regular walking beam heating furnace. In addition, in the case where adjustment is performed under the condition that slippage occurs or uniform heating is deteriorated, in addition to the load value, the current value is rolled when adjustment is performed between the rolling stands 41 and 51 as described above. Known current memory load receivers with a scheme of using ratios or performing adjustments in the stands 31 and 41 are most preferred, but do not necessarily require fixing the device and require more than two components. Snapping to multiple stands makes it possible to use known full length adjustment systems in which adjustments affect the overall length.

의 빌레트가 300

의 연속 주조블루움으로부터 제조되는 경우의 배치와 빌레트밀의 실시예를 보여주고 있다. 이러한 경우 전체 압연기의 부품수효는 4-5개의 스탠드이며, 가령 제조가 가능하다고 실시예는 도식적인 것이다. 압연스탠드 사이의 신장율 분포는 다음 표와 같다.Known adjustment methods can be used in which the tension generated between the stands is directly detected and then reduced to zero. Figure 10 shows the case where a total growth rate of 6.25 is required.

Billet 300

Examples of batches and billet mills when produced from continuous casting blues of are shown. In this case, the number of parts of the whole rolling mill is 4-5 stands, for example, the embodiment is schematic. The elongation distribution between the rolling stands is shown in the following table.

Table 2 shows that the small elongation occurred in the primary stand and the rolling mill is of a much simpler type than the conventional rolling mill, and the main purpose is to engage the workpiece in the secondary stand.

TABLE 2

Note: The symbols of the grooves show the following shapes, each of which is shown in Fig. 2.

D: Diamond DS: Square similar to diamond S: Square

Stands 2 and 3 have a high elongation which is well above the conventional level. In stand 4, even if high elongation is employed, a diamond groove with a similar axis-groove ratio of 1.0 is used to obtain a workpiece similar to the square final section. Therefore, only small elongation is required for stand 5 and the dimensional change due to the width change in the rolled workpiece at the exit of stand 4 is entirely eliminated, resulting in a product with high dimensional accuracy and extremely good shape. Can be.

Furthermore, the rolling mill of stand 5 can be of compact dimensions.

Considered as a group of rolling mills, this arrangement can produce extremely simple billet mills. And since stand 1 and stand 5 can be of extremely simple dimensions, substantially the overall elongation can be obtained with the stand 3.

Therefore, even if the rolling speed can be selected in relation to the dimensions of the mill, as a normal rolling work factor, for a mill of 50,000 tons / month to 200,000 tons / month, the rolling speed is sufficiently within the range of the effective rolling speed shown in FIG. Can also be chosen freely.

Table 3 shows that stands 1 and 4 are adjusted at the conventional rolling level and high elongation is applied to stands 2 and 3, and the dimensional accuracy is slightly less than Table 2 and Show that you are in a rough dimension. Overall, however, the adjustment of stand # 4 is sufficient to carry out the work and is an arrangement having advantages in the line length of the mill and in the installation.

TABLE 3

Note: Symbols of grooves are shown in Table 1.

로 부터 120

까지의 제품을 생산하기위해서는 약 8번의 통과가 필요하다. 그리고 브레이크 다움 밀(break down mill) 1개, 연속밀 4개 또는 7-8스탠드의 연속밀이 부가된다. 따라서 이에 의해서 종래의 밀 그룹이 본 발명의 장치와 비교해서 상당히 큰 시설을 요구한다는 것이 통상적인 실시이다.Therefore, in the group of rolling mills according to the conventional method,

From 120

It takes about eight passes to produce the products up to. Then, one break down mill, four continuous mills or 7-8 stands of continuous mills are added. It is therefore common practice that conventional mill groups require significantly larger facilities compared to the apparatus of the present invention.

Next, the arrangement in which round bars are made will be made in relation to FIG. A workpiece having a square cross section is formed from Bluum by using the process shown in FIG. 10A.

Thereafter, at least two rolling mills with regularly reduced cross sections are arranged as a continuous process, thus making it possible to essentially make round bars.

Generally, however, the required dimensions of a round bar vary by a few millimeters and are of various midrange widths.

Therefore, it is necessary to increase the rolling stand because it depends on the range of dimensions.

In the case of a round bar whose cross section is similar to the cross section of the starting material, it is not necessary to take an excessively high elongation and a groove for the manufacture of the round bar in the process of FIG. 10a is provided and can be manufactured thereby.

Thus, two types of 13a, b degrees and both can be adopted for the manufacture of round bars, such as the latter half, oval and groove in the round.

In order to achieve high elongation in one pass, there is a separation point in comparison with the aforementioned diamond or square groove. The examples describe the case of bars and rolling lines in FIG. 10C.

의 실시예로 부터 5.5

에 이르기까지 명백하여진 바와 같이 전체적인 신장은 약 500 정도의 높은 신장을 요구한다.120 normal for bars and rods

5.5 from the embodiment

As apparent from the overall elongation requires as high as about 500.

Thus many mills with high elongation of the rows of rolling stands 28 are adjusted by the dimensions of the workpiece and the maximum rolling speed.

A typical example of a bar and rod is a rough mill manufactured with 200 millimeter bar steel and round mills from 120 millimeters to 5.5 millimeters with finishing at speeds of 20 M / sec (1200 M / min) and 60 M / sec (3600 M / min). Are shown in Table 1 and Table 5.

Table 4

The numbers in parentheses indicate the corresponding changed dimensions of the square cross section.

Table 5

The numbers in parentheses indicate the corresponding changed dimensions of the square cross section.

Table 4 shows an example of a bar steel rolling line where a high elongation rolling mill is placed in stands 2-5. The reason for arranging the rolling mill with high elongation up to 5 is that the rolling speed after the 5th stand exceeds the effective rolling speed range shown in FIG. Therefore, longitudinal stands of the corresponding contact angle range, adjusted by curve IV, are performed on stands after stand # 6.

Table 5 also shows examples of rod rolling lines. The rolling mill with high elongation here is arranged in stands 2-6. In this case, the rolling speed in the stands after the seventh stand exceeds the effective rolling speed range shown in FIG.

In other words, there are 4 stands with high elongation of 1.8 in Table 4 and 5 in Table 5, and the total elongation with the rough rolling stand is 1.2 × 1.8 ⁴ = 12.6 in Table 4 and 1.2 × 1.8 ⁵ = 22.7 in Table 5. To reach. In a conventional rolling mill having a elongation level of 1.25 in one pass, 11-14 stands are required if these total elongations are affected by the rough rolling mill. In contrast, in the present invention, the number of stands of the rough rolling mill is 5-6, so that 6-8 stands are removed. Therefore, the effect on the present invention is surprising. In the case of this invention it is also a very good arrangement for a facility which includes this as short as possible, to significantly reduce the cost.

Of course, the rolling effect of simplifying the rolling mill in the above-described embodiment is considered. And rolling mill fundamental principle with the maximum angle shown in FIG. For example, even if the diameter of the roll becomes relatively smaller as a whole facility, there is a higher effect as described above.

Claims (1)

The contact angle θ between the rolled roll and the workpiece is θ

primary rolling stand (5) in which the roller spacing is set such that tan ^-1 μ (μ: coefficient of friction between the rolling roll and the workpiece), the contact angle θ is at least θ

for detecting the circumferential speed of the working rollers of a plurality of secondary rolling stands 5a and 5b and secondary rolling stands 5a, which are set at a roller interval to be tan ⁻¹ μ and arranged in series behind the primary rolling stand. Speed detecting means 15a, means for detecting the completion of the bite of the workpiece in the secondary rolling stand 5a, 8a, compressive stress of about 1% and yield stress of less than 100% The roller circumferential speed of the primary rolling stand 5 is adjusted based on the signal from the speed detecting means 15a so as to occur on the workpiece on the inlet side of the primary rolling stand 5a, and the workpiece is the secondary rolling stand 5a. Circumference of the roll of the primary or secondary rolling stand 5 or 5a based on a signal from the bite completion detecting means so that a stress does not occur on the workpiece on the inlet side of the secondary rolling stand 5a after being bitten by In the means (14) for adjusting the speed, the secondary rolling stand (5a) Arithmetic processing means (12, 12a) and a bite which memorize the slip limit curves related to the contact angle and the rolling speed, and compare the slip limit speed with the speed signal from the speed detector (15a) to generate a speed correction value as an output; A rolling device of a metal workpiece composed of means (14a) for adjusting the circumferential speed of the roll of the secondary rolling stand (5a) in response to a completion signal and a speed correction value signal.

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